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doc/Makefile
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MD_TARGETS=$(addsuffix .xml, $(basename $(wildcard ./*.md ./**/*.md)))
.PHONY: all
all: validate out/html/index.html out/epub/manual.epub
all: validate format out/html/index.html out/epub/manual.epub
.PHONY: debug
debug:
nix-shell --run "xmloscopy --docbook5 ./manual.xml ./manual-full.xml"
.PHONY: format
format:
find . -iname '*.xml' -type f -print0 | xargs -0 -I{} -n1 \
xmlformat --config-file "$$XMLFORMAT_CONFIG" -i {}
.PHONY: clean
clean:
rm -f ${MD_TARGETS} .version manual-full.xml

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@ -1,42 +1,51 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-packageconfig">
<title>Global configuration</title>
<para>Nix comes with certain defaults about what packages can and
cannot be installed, based on a package's metadata. By default, Nix
will prevent installation if any of the following criteria are
true:</para>
<itemizedlist>
<listitem><para>The package is thought to be broken, and has had
its <literal>meta.broken</literal> set to
<literal>true</literal>.</para></listitem>
<listitem><para>The package isn't intended to run on the given system, as none of its <literal>meta.platforms</literal> match the given system.</para></listitem>
<listitem><para>The package's <literal>meta.license</literal> is set
to a license which is considered to be unfree.</para></listitem>
<listitem><para>The package has known security vulnerabilities but
has not or can not be updated for some reason, and a list of issues
has been entered in to the package's
<literal>meta.knownVulnerabilities</literal>.</para></listitem>
</itemizedlist>
<para>Note that all this is checked during evaluation already,
and the check includes any package that is evaluated.
In particular, all build-time dependencies are checked.
<literal>nix-env -qa</literal> will (attempt to) hide any packages
that would be refused.
</para>
<para>Each of these criteria can be altered in the nixpkgs
configuration.</para>
<para>The nixpkgs configuration for a NixOS system is set in the
<literal>configuration.nix</literal>, as in the following example:
<title>Global configuration</title>
<para>
Nix comes with certain defaults about what packages can and cannot be
installed, based on a package's metadata. By default, Nix will prevent
installation if any of the following criteria are true:
</para>
<itemizedlist>
<listitem>
<para>
The package is thought to be broken, and has had its
<literal>meta.broken</literal> set to <literal>true</literal>.
</para>
</listitem>
<listitem>
<para>
The package isn't intended to run on the given system, as none of its
<literal>meta.platforms</literal> match the given system.
</para>
</listitem>
<listitem>
<para>
The package's <literal>meta.license</literal> is set to a license which is
considered to be unfree.
</para>
</listitem>
<listitem>
<para>
The package has known security vulnerabilities but has not or can not be
updated for some reason, and a list of issues has been entered in to the
package's <literal>meta.knownVulnerabilities</literal>.
</para>
</listitem>
</itemizedlist>
<para>
Note that all this is checked during evaluation already, and the check
includes any package that is evaluated. In particular, all build-time
dependencies are checked. <literal>nix-env -qa</literal> will (attempt to)
hide any packages that would be refused.
</para>
<para>
Each of these criteria can be altered in the nixpkgs configuration.
</para>
<para>
The nixpkgs configuration for a NixOS system is set in the
<literal>configuration.nix</literal>, as in the following example:
<programlisting>
{
nixpkgs.config = {
@ -44,187 +53,197 @@ configuration.</para>
};
}
</programlisting>
However, this does not allow unfree software for individual users.
Their configurations are managed separately.</para>
<para>A user's of nixpkgs configuration is stored in a user-specific
configuration file located at
<filename>~/.config/nixpkgs/config.nix</filename>. For example:
However, this does not allow unfree software for individual users. Their
configurations are managed separately.
</para>
<para>
A user's of nixpkgs configuration is stored in a user-specific configuration
file located at <filename>~/.config/nixpkgs/config.nix</filename>. For
example:
<programlisting>
{
allowUnfree = true;
}
</programlisting>
</para>
<para>Note that we are not able to test or build unfree software on Hydra
due to policy. Most unfree licenses prohibit us from either executing or
distributing the software.</para>
<section xml:id="sec-allow-broken">
</para>
<para>
Note that we are not able to test or build unfree software on Hydra due to
policy. Most unfree licenses prohibit us from either executing or
distributing the software.
</para>
<section xml:id="sec-allow-broken">
<title>Installing broken packages</title>
<para>There are two ways to try compiling a package which has been
marked as broken.</para>
<para>
There are two ways to try compiling a package which has been marked as
broken.
</para>
<itemizedlist>
<listitem><para>
For allowing the build of a broken package once, you can use an
environment variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_BROKEN=1</programlisting>
</para></listitem>
<listitem><para>
For permanently allowing broken packages to be built, you may
add <literal>allowBroken = true;</literal> to your user's
configuration file, like this:
<listitem>
<para>
For allowing the build of a broken package once, you can use an
environment variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_BROKEN=1</programlisting>
</para>
</listitem>
<listitem>
<para>
For permanently allowing broken packages to be built, you may add
<literal>allowBroken = true;</literal> to your user's configuration file,
like this:
<programlisting>
{
allowBroken = true;
}
</programlisting>
</para></listitem>
</para>
</listitem>
</itemizedlist>
</section>
<section xml:id="sec-allow-unsupported-system">
</section>
<section xml:id="sec-allow-unsupported-system">
<title>Installing packages on unsupported systems</title>
<para>
There are also two ways to try compiling a package which has been marked as unsuported for the given system.
There are also two ways to try compiling a package which has been marked as
unsuported for the given system.
</para>
<itemizedlist>
<listitem><para>
For allowing the build of a broken package once, you can use an environment variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_UNSUPPORTED_SYSTEM=1</programlisting>
</para></listitem>
<listitem>
<para>
For permanently allowing broken packages to be built, you may add <literal>allowUnsupportedSystem = true;</literal> to your user's configuration file, like this:
<listitem>
<para>
For allowing the build of a broken package once, you can use an
environment variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_UNSUPPORTED_SYSTEM=1</programlisting>
</para>
</listitem>
<listitem>
<para>
For permanently allowing broken packages to be built, you may add
<literal>allowUnsupportedSystem = true;</literal> to your user's
configuration file, like this:
<programlisting>
{
allowUnsupportedSystem = true;
}
</programlisting>
</para>
</listitem>
</para>
</listitem>
</itemizedlist>
<para>
The difference between an a package being unsupported on some system and being broken is admittedly a bit fuzzy.
If a program <emphasis>ought</emphasis> to work on a certain platform, but doesn't, the platform should be included in <literal>meta.platforms</literal>, but marked as broken with e.g. <literal>meta.broken = !hostPlatform.isWindows</literal>.
Of course, this begs the question of what "ought" means exactly.
That is left to the package maintainer.
The difference between an a package being unsupported on some system and
being broken is admittedly a bit fuzzy. If a program
<emphasis>ought</emphasis> to work on a certain platform, but doesn't, the
platform should be included in <literal>meta.platforms</literal>, but marked
as broken with e.g. <literal>meta.broken =
!hostPlatform.isWindows</literal>. Of course, this begs the question of what
"ought" means exactly. That is left to the package maintainer.
</para>
</section>
<section xml:id="sec-allow-unfree">
</section>
<section xml:id="sec-allow-unfree">
<title>Installing unfree packages</title>
<para>There are several ways to tweak how Nix handles a package
which has been marked as unfree.</para>
<para>
There are several ways to tweak how Nix handles a package which has been
marked as unfree.
</para>
<itemizedlist>
<listitem><para>
To temporarily allow all unfree packages, you can use an
environment variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_UNFREE=1</programlisting>
</para></listitem>
<listitem><para>
It is possible to permanently allow individual unfree packages,
while still blocking unfree packages by default using the
<literal>allowUnfreePredicate</literal> configuration
option in the user configuration file.</para>
<para>This option is a function which accepts a package as a
parameter, and returns a boolean. The following example
configuration accepts a package and always returns false:
<listitem>
<para>
To temporarily allow all unfree packages, you can use an environment
variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_UNFREE=1</programlisting>
</para>
</listitem>
<listitem>
<para>
It is possible to permanently allow individual unfree packages, while
still blocking unfree packages by default using the
<literal>allowUnfreePredicate</literal> configuration option in the user
configuration file.
</para>
<para>
This option is a function which accepts a package as a parameter, and
returns a boolean. The following example configuration accepts a package
and always returns false:
<programlisting>
{
allowUnfreePredicate = (pkg: false);
}
</programlisting>
</para>
<para>A more useful example, the following configuration allows
only allows flash player and visual studio code:
</para>
<para>
A more useful example, the following configuration allows only allows
flash player and visual studio code:
<programlisting>
{
allowUnfreePredicate = (pkg: elem (builtins.parseDrvName pkg.name).name [ "flashplayer" "vscode" ]);
}
</programlisting>
</para></listitem>
<listitem>
<para>It is also possible to whitelist and blacklist licenses
that are specifically acceptable or not acceptable, using
<literal>whitelistedLicenses</literal> and
<literal>blacklistedLicenses</literal>, respectively.
</para>
<para>The following example configuration whitelists the
licenses <literal>amd</literal> and <literal>wtfpl</literal>:
</para>
</listitem>
<listitem>
<para>
It is also possible to whitelist and blacklist licenses that are
specifically acceptable or not acceptable, using
<literal>whitelistedLicenses</literal> and
<literal>blacklistedLicenses</literal>, respectively.
</para>
<para>
The following example configuration whitelists the licenses
<literal>amd</literal> and <literal>wtfpl</literal>:
<programlisting>
{
whitelistedLicenses = with stdenv.lib.licenses; [ amd wtfpl ];
}
</programlisting>
</para>
<para>The following example configuration blacklists the
<literal>gpl3</literal> and <literal>agpl3</literal> licenses:
</para>
<para>
The following example configuration blacklists the <literal>gpl3</literal>
and <literal>agpl3</literal> licenses:
<programlisting>
{
blacklistedLicenses = with stdenv.lib.licenses; [ agpl3 gpl3 ];
}
</programlisting>
</para>
</listitem>
</para>
</listitem>
</itemizedlist>
<para>A complete list of licenses can be found in the file
<filename>lib/licenses.nix</filename> of the nixpkgs tree.</para>
</section>
<para>
A complete list of licenses can be found in the file
<filename>lib/licenses.nix</filename> of the nixpkgs tree.
</para>
</section>
<section xml:id="sec-allow-insecure">
<title>Installing insecure packages</title>
<section xml:id="sec-allow-insecure">
<title>
Installing insecure packages
</title>
<para>There are several ways to tweak how Nix handles a package
which has been marked as insecure.</para>
<para>
There are several ways to tweak how Nix handles a package which has been
marked as insecure.
</para>
<itemizedlist>
<listitem><para>
To temporarily allow all insecure packages, you can use an
environment variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_INSECURE=1</programlisting>
</para></listitem>
<listitem><para>
It is possible to permanently allow individual insecure
packages, while still blocking other insecure packages by
default using the <literal>permittedInsecurePackages</literal>
configuration option in the user configuration file.</para>
<para>The following example configuration permits the
installation of the hypothetically insecure package
<literal>hello</literal>, version <literal>1.2.3</literal>:
<listitem>
<para>
To temporarily allow all insecure packages, you can use an environment
variable for a single invocation of the nix tools:
<programlisting>$ export NIXPKGS_ALLOW_INSECURE=1</programlisting>
</para>
</listitem>
<listitem>
<para>
It is possible to permanently allow individual insecure packages, while
still blocking other insecure packages by default using the
<literal>permittedInsecurePackages</literal> configuration option in the
user configuration file.
</para>
<para>
The following example configuration permits the installation of the
hypothetically insecure package <literal>hello</literal>, version
<literal>1.2.3</literal>:
<programlisting>
{
permittedInsecurePackages = [
@ -232,47 +251,44 @@ distributing the software.</para>
];
}
</programlisting>
</para>
</listitem>
<listitem><para>
It is also possible to create a custom policy around which
insecure packages to allow and deny, by overriding the
<literal>allowInsecurePredicate</literal> configuration
option.</para>
<para>The <literal>allowInsecurePredicate</literal> option is a
function which accepts a package and returns a boolean, much
like <literal>allowUnfreePredicate</literal>.</para>
<para>The following configuration example only allows insecure
packages with very short names:
</para>
</listitem>
<listitem>
<para>
It is also possible to create a custom policy around which insecure
packages to allow and deny, by overriding the
<literal>allowInsecurePredicate</literal> configuration option.
</para>
<para>
The <literal>allowInsecurePredicate</literal> option is a function which
accepts a package and returns a boolean, much like
<literal>allowUnfreePredicate</literal>.
</para>
<para>
The following configuration example only allows insecure packages with
very short names:
<programlisting>
{
allowInsecurePredicate = (pkg: (builtins.stringLength (builtins.parseDrvName pkg.name).name) &lt;= 5);
}
</programlisting>
</para>
<para>Note that <literal>permittedInsecurePackages</literal> is
only checked if <literal>allowInsecurePredicate</literal> is not
specified.
</para></listitem>
</para>
<para>
Note that <literal>permittedInsecurePackages</literal> is only checked if
<literal>allowInsecurePredicate</literal> is not specified.
</para>
</listitem>
</itemizedlist>
</section>
</section>
<!--============================================================-->
<section xml:id="sec-modify-via-packageOverrides">
<title>Modify packages via <literal>packageOverrides</literal></title>
<section xml:id="sec-modify-via-packageOverrides"><title>Modify
packages via <literal>packageOverrides</literal></title>
<para>You can define a function called
<varname>packageOverrides</varname> in your local
<filename>~/.config/nixpkgs/config.nix</filename> to override nix packages. It
must be a function that takes pkgs as an argument and return modified
set of packages.
<para>
You can define a function called <varname>packageOverrides</varname> in your
local <filename>~/.config/nixpkgs/config.nix</filename> to override nix
packages. It must be a function that takes pkgs as an argument and return
modified set of packages.
<programlisting>
{
packageOverrides = pkgs: rec {
@ -280,30 +296,27 @@ set of packages.
};
}
</programlisting>
</para>
</section>
<section xml:id="sec-declarative-package-management">
</para>
</section>
<section xml:id="sec-declarative-package-management">
<title>Declarative Package Management</title>
<section xml:id="sec-building-environment">
<title>Build an environment</title>
<title>Build an environment</title>
<para>
Using <literal>packageOverrides</literal>, it is possible to manage
packages declaratively. This means that we can list all of our desired
packages within a declarative Nix expression. For example, to have
<literal>aspell</literal>, <literal>bc</literal>,
<literal>ffmpeg</literal>, <literal>coreutils</literal>,
<literal>gdb</literal>, <literal>nixUnstable</literal>,
<literal>emscripten</literal>, <literal>jq</literal>,
<literal>nox</literal>, and <literal>silver-searcher</literal>, we could
use the following in <filename>~/.config/nixpkgs/config.nix</filename>:
</para>
<para>
Using <literal>packageOverrides</literal>, it is possible to manage
packages declaratively. This means that we can list all of our desired
packages within a declarative Nix expression. For example, to have
<literal>aspell</literal>, <literal>bc</literal>,
<literal>ffmpeg</literal>, <literal>coreutils</literal>,
<literal>gdb</literal>, <literal>nixUnstable</literal>,
<literal>emscripten</literal>, <literal>jq</literal>,
<literal>nox</literal>, and <literal>silver-searcher</literal>, we could
use the following in <filename>~/.config/nixpkgs/config.nix</filename>:
</para>
<screen>
<screen>
{
packageOverrides = pkgs: with pkgs; {
myPackages = pkgs.buildEnv {
@ -314,17 +327,17 @@ set of packages.
}
</screen>
<para>
To install it into our environment, you can just run <literal>nix-env -iA
nixpkgs.myPackages</literal>. If you want to load the packages to be built
from a working copy of <literal>nixpkgs</literal> you just run
<literal>nix-env -f. -iA myPackages</literal>. To explore what's been
installed, just look through <filename>~/.nix-profile/</filename>. You can
see that a lot of stuff has been installed. Some of this stuff is useful
some of it isn't. Let's tell Nixpkgs to only link the stuff that we want:
</para>
<para>
To install it into our environment, you can just run <literal>nix-env -iA
nixpkgs.myPackages</literal>. If you want to load the packages to be built
from a working copy of <literal>nixpkgs</literal> you just run
<literal>nix-env -f. -iA myPackages</literal>. To explore what's been
installed, just look through <filename>~/.nix-profile/</filename>. You can
see that a lot of stuff has been installed. Some of this stuff is useful
some of it isn't. Let's tell Nixpkgs to only link the stuff that we want:
</para>
<screen>
<screen>
{
packageOverrides = pkgs: with pkgs; {
myPackages = pkgs.buildEnv {
@ -336,31 +349,30 @@ set of packages.
}
</screen>
<para>
<literal>pathsToLink</literal> tells Nixpkgs to only link the paths listed
which gets rid of the extra stuff in the profile.
<filename>/bin</filename> and <filename>/share</filename> are good
defaults for a user environment, getting rid of the clutter. If you are
running on Nix on MacOS, you may want to add another path as well,
<filename>/Applications</filename>, that makes GUI apps available.
</para>
<para>
<literal>pathsToLink</literal> tells Nixpkgs to only link the paths listed
which gets rid of the extra stuff in the profile. <filename>/bin</filename>
and <filename>/share</filename> are good defaults for a user environment,
getting rid of the clutter. If you are running on Nix on MacOS, you may
want to add another path as well, <filename>/Applications</filename>, that
makes GUI apps available.
</para>
</section>
<section xml:id="sec-getting-documentation">
<title>Getting documentation</title>
<title>Getting documentation</title>
<para>
After building that new environment, look through
<filename>~/.nix-profile</filename> to make sure everything is there that
we wanted. Discerning readers will note that some files are missing. Look
inside <filename>~/.nix-profile/share/man/man1/</filename> to verify this.
There are no man pages for any of the Nix tools! This is because some
packages like Nix have multiple outputs for things like documentation (see
section 4). Let's make Nix install those as well.
</para>
<para>
After building that new environment, look through
<filename>~/.nix-profile</filename> to make sure everything is there that
we wanted. Discerning readers will note that some files are missing. Look
inside <filename>~/.nix-profile/share/man/man1/</filename> to verify this.
There are no man pages for any of the Nix tools! This is because some
packages like Nix have multiple outputs for things like documentation (see
section 4). Let's make Nix install those as well.
</para>
<screen>
<screen>
{
packageOverrides = pkgs: with pkgs; {
myPackages = pkgs.buildEnv {
@ -373,14 +385,13 @@ set of packages.
}
</screen>
<para>
This provides us with some useful documentation for using our packages.
However, if we actually want those manpages to be detected by man, we need
to set up our environment. This can also be managed within Nix
expressions.
</para>
<para>
This provides us with some useful documentation for using our packages.
However, if we actually want those manpages to be detected by man, we need
to set up our environment. This can also be managed within Nix expressions.
</para>
<screen>
<screen>
{
packageOverrides = pkgs: with pkgs; rec {
myProfile = writeText "my-profile" ''
@ -412,13 +423,13 @@ cp ${myProfile} $out/etc/profile.d/my-profile.sh
}
</screen>
<para>
For this to work fully, you must also have this script sourced when you
are logged in. Try adding something like this to your
<filename>~/.profile</filename> file:
</para>
<para>
For this to work fully, you must also have this script sourced when you are
logged in. Try adding something like this to your
<filename>~/.profile</filename> file:
</para>
<screen>
<screen>
#!/bin/sh
if [ -d $HOME/.nix-profile/etc/profile.d ]; then
for i in $HOME/.nix-profile/etc/profile.d/*.sh; do
@ -429,23 +440,22 @@ if [ -d $HOME/.nix-profile/etc/profile.d ]; then
fi
</screen>
<para>
Now just run <literal>source $HOME/.profile</literal> and you can starting
loading man pages from your environent.
</para>
<para>
Now just run <literal>source $HOME/.profile</literal> and you can starting
loading man pages from your environent.
</para>
</section>
<section xml:id="sec-gnu-info-setup">
<title>GNU info setup</title>
<title>GNU info setup</title>
<para>
Configuring GNU info is a little bit trickier than man pages. To work
correctly, info needs a database to be generated. This can be done with
some small modifications to our environment scripts.
</para>
<para>
Configuring GNU info is a little bit trickier than man pages. To work
correctly, info needs a database to be generated. This can be done with
some small modifications to our environment scripts.
</para>
<screen>
<screen>
{
packageOverrides = pkgs: with pkgs; rec {
myProfile = writeText "my-profile" ''
@ -487,16 +497,13 @@ cp ${myProfile} $out/etc/profile.d/my-profile.sh
}
</screen>
<para>
<literal>postBuild</literal> tells Nixpkgs to run a command after building
the environment. In this case, <literal>install-info</literal> adds the
installed info pages to <literal>dir</literal> which is GNU info's default
root node. Note that <literal>texinfoInteractive</literal> is added to the
environment to give the <literal>install-info</literal> command.
</para>
<para>
<literal>postBuild</literal> tells Nixpkgs to run a command after building
the environment. In this case, <literal>install-info</literal> adds the
installed info pages to <literal>dir</literal> which is GNU info's default
root node. Note that <literal>texinfoInteractive</literal> is added to the
environment to give the <literal>install-info</literal> command.
</para>
</section>
</section>
</section>
</chapter>

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@ -1,35 +1,35 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-contributing">
<title>Contributing to this documentation</title>
<para>The DocBook sources of the Nixpkgs manual are in the <filename
<title>Contributing to this documentation</title>
<para>
The DocBook sources of the Nixpkgs manual are in the
<filename
xlink:href="https://github.com/NixOS/nixpkgs/tree/master/doc">doc</filename>
subdirectory of the Nixpkgs repository.</para>
<para>You can quickly check your edits with <command>make</command>:</para>
subdirectory of the Nixpkgs repository.
</para>
<para>
You can quickly check your edits with <command>make</command>:
</para>
<screen>
$ cd /path/to/nixpkgs/doc
$ nix-shell
[nix-shell]$ make
</screen>
<para>If you experience problems, run <command>make debug</command>
to help understand the docbook errors.</para>
<para>After making modifications to the manual, it's important to
build it before committing. You can do that as follows:
<para>
If you experience problems, run <command>make debug</command> to help
understand the docbook errors.
</para>
<para>
After making modifications to the manual, it's important to build it before
committing. You can do that as follows:
<screen>
$ cd /path/to/nixpkgs/doc
$ nix-shell
[nix-shell]$ make clean
[nix-shell]$ nix-build .
</screen>
If the build succeeds, the manual will be in
<filename>./result/share/doc/nixpkgs/manual.html</filename>.</para>
If the build succeeds, the manual will be in
<filename>./result/share/doc/nixpkgs/manual.html</filename>.
</para>
</chapter>

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<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-cross">
<title>Cross-compilation</title>
<section xml:id="sec-cross-intro">
<title>Cross-compilation</title>
<section xml:id="sec-cross-intro">
<title>Introduction</title>
<para>
"Cross-compilation" means compiling a program on one machine for another type of machine.
For example, a typical use of cross compilation is to compile programs for embedded devices.
These devices often don't have the computing power and memory to compile their own programs.
One might think that cross-compilation is a fairly niche concern, but there are advantages to being rigorous about distinguishing build-time vs run-time environments even when one is developing and deploying on the same machine.
Nixpkgs is increasingly adopting the opinion that packages should be written with cross-compilation in mind, and nixpkgs should evaluate in a similar way (by minimizing cross-compilation-specific special cases) whether or not one is cross-compiling.
"Cross-compilation" means compiling a program on one machine for another
type of machine. For example, a typical use of cross compilation is to
compile programs for embedded devices. These devices often don't have the
computing power and memory to compile their own programs. One might think
that cross-compilation is a fairly niche concern, but there are advantages
to being rigorous about distinguishing build-time vs run-time environments
even when one is developing and deploying on the same machine. Nixpkgs is
increasingly adopting the opinion that packages should be written with
cross-compilation in mind, and nixpkgs should evaluate in a similar way (by
minimizing cross-compilation-specific special cases) whether or not one is
cross-compiling.
</para>
<para>
This chapter will be organized in three parts.
First, it will describe the basics of how to package software in a way that supports cross-compilation.
Second, it will describe how to use Nixpkgs when cross-compiling.
Third, it will describe the internal infrastructure supporting cross-compilation.
This chapter will be organized in three parts. First, it will describe the
basics of how to package software in a way that supports cross-compilation.
Second, it will describe how to use Nixpkgs when cross-compiling. Third, it
will describe the internal infrastructure supporting cross-compilation.
</para>
</section>
</section>
<!--============================================================-->
<section xml:id="sec-cross-packaging">
<section xml:id="sec-cross-packaging">
<title>Packaging in a cross-friendly manner</title>
<section>
<title>Platform parameters</title>
<para>
Nixpkgs follows the <link xlink:href="https://gcc.gnu.org/onlinedocs/gccint/Configure-Terms.html">common historical convention of GNU autoconf</link> of distinguishing between 3 types of platform: <wordasword>build</wordasword>, <wordasword>host</wordasword>, and <wordasword>target</wordasword>.
<title>Platform parameters</title>
In summary, <wordasword>build</wordasword> is the platform on which a package is being built, <wordasword>host</wordasword> is the platform on which it is to run. The third attribute, <wordasword>target</wordasword>, is relevant only for certain specific compilers and build tools.
</para>
<para>
Nixpkgs follows the
<link xlink:href="https://gcc.gnu.org/onlinedocs/gccint/Configure-Terms.html">common
historical convention of GNU autoconf</link> of distinguishing between 3
types of platform: <wordasword>build</wordasword>,
<wordasword>host</wordasword>, and <wordasword>target</wordasword>. In
summary, <wordasword>build</wordasword> is the platform on which a package
is being built, <wordasword>host</wordasword> is the platform on which it
is to run. The third attribute, <wordasword>target</wordasword>, is
relevant only for certain specific compilers and build tools.
</para>
<para>
In Nixpkgs, these three platforms are defined as attribute sets under the names <literal>buildPlatform</literal>, <literal>hostPlatform</literal>, and <literal>targetPlatform</literal>.
All three are always defined as attributes in the standard environment, and at the top level. That means one can get at them just like a dependency in a function that is imported with <literal>callPackage</literal>:
<programlisting>{ stdenv, buildPlatform, hostPlatform, fooDep, barDep, .. }: ...buildPlatform...</programlisting>, or just off <varname>stdenv</varname>:
<programlisting>{ stdenv, fooDep, barDep, .. }: ...stdenv.buildPlatform...</programlisting>.
</para>
<variablelist>
<varlistentry>
<term><varname>buildPlatform</varname></term>
<listitem><para>
The "build platform" is the platform on which a package is built.
Once someone has a built package, or pre-built binary package, the build platform should not matter and be safe to ignore.
</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>hostPlatform</varname></term>
<listitem><para>
The "host platform" is the platform on which a package will be run.
This is the simplest platform to understand, but also the one with the worst name.
</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>targetPlatform</varname></term>
<listitem>
<para>
The "target platform" attribute is, unlike the other two attributes, not actually fundamental to the process of building software.
Instead, it is only relevant for compatibility with building certain specific compilers and build tools.
It can be safely ignored for all other packages.
</para>
<para>
The build process of certain compilers is written in such a way that the compiler resulting from a single build can itself only produce binaries for a single platform.
The task specifying this single "target platform" is thus pushed to build time of the compiler.
The root cause of this mistake is often that the compiler (which will be run on the host) and the the standard library/runtime (which will be run on the target) are built by a single build process.
</para>
<para>
There is no fundamental need to think about a single target ahead of time like this.
If the tool supports modular or pluggable backends, both the need to specify the target at build time and the constraint of having only a single target disappear.
An example of such a tool is LLVM.
</para>
<para>
Although the existence of a "target platfom" is arguably a historical mistake, it is a common one: examples of tools that suffer from it are GCC, Binutils, GHC and Autoconf.
Nixpkgs tries to avoid sharing in the mistake where possible.
Still, because the concept of a target platform is so ingrained, it is best to support it as is.
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
The exact schema these fields follow is a bit ill-defined due to a long and convoluted evolution, but this is slowly being cleaned up.
You can see examples of ones used in practice in <literal>lib.systems.examples</literal>; note how they are not all very consistent.
For now, here are few fields can count on them containing:
</para>
<variablelist>
<varlistentry>
<term><varname>system</varname></term>
<listitem>
<para>
This is a two-component shorthand for the platform.
Examples of this would be "x86_64-darwin" and "i686-linux"; see <literal>lib.systems.doubles</literal> for more.
This format isn't very standard, but has built-in support in Nix, such as the <varname>builtins.currentSystem</varname> impure string.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>config</varname></term>
<listitem>
<para>
This is a 3- or 4- component shorthand for the platform.
Examples of this would be "x86_64-unknown-linux-gnu" and "aarch64-apple-darwin14".
This is a standard format called the "LLVM target triple", as they are pioneered by LLVM and traditionally just used for the <varname>targetPlatform</varname>.
This format is strictly more informative than the "Nix host double", as the previous format could analogously be termed.
This needs a better name than <varname>config</varname>!
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>parsed</varname></term>
<listitem>
<para>
This is a nix representation of a parsed LLVM target triple with white-listed components.
This can be specified directly, or actually parsed from the <varname>config</varname>.
[Technically, only one need be specified and the others can be inferred, though the precision of inference may not be very good.]
See <literal>lib.systems.parse</literal> for the exact representation.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>libc</varname></term>
<listitem>
<para>
This is a string identifying the standard C library used.
Valid identifiers include "glibc" for GNU libc, "libSystem" for Darwin's Libsystem, and "uclibc" for µClibc.
It should probably be refactored to use the module system, like <varname>parse</varname>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>is*</varname></term>
<listitem>
<para>
These predicates are defined in <literal>lib.systems.inspect</literal>, and slapped on every platform.
They are superior to the ones in <varname>stdenv</varname> as they force the user to be explicit about which platform they are inspecting.
Please use these instead of those.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>platform</varname></term>
<listitem>
<para>
This is, quite frankly, a dumping ground of ad-hoc settings (it's an attribute set).
See <literal>lib.systems.platforms</literal> for examples—there's hopefully one in there that will work verbatim for each platform that is working.
Please help us triage these flags and give them better homes!
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
In Nixpkgs, these three platforms are defined as attribute sets under the
names <literal>buildPlatform</literal>, <literal>hostPlatform</literal>,
and <literal>targetPlatform</literal>. All three are always defined as
attributes in the standard environment, and at the top level. That means
one can get at them just like a dependency in a function that is imported
with <literal>callPackage</literal>:
<programlisting>{ stdenv, buildPlatform, hostPlatform, fooDep, barDep, .. }: ...buildPlatform...</programlisting>
, or just off <varname>stdenv</varname>:
<programlisting>{ stdenv, fooDep, barDep, .. }: ...stdenv.buildPlatform...</programlisting>
.
</para>
<variablelist>
<varlistentry>
<term><varname>buildPlatform</varname>
</term>
<listitem>
<para>
The "build platform" is the platform on which a package is built. Once
someone has a built package, or pre-built binary package, the build
platform should not matter and be safe to ignore.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>hostPlatform</varname>
</term>
<listitem>
<para>
The "host platform" is the platform on which a package will be run. This
is the simplest platform to understand, but also the one with the worst
name.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>targetPlatform</varname>
</term>
<listitem>
<para>
The "target platform" attribute is, unlike the other two attributes, not
actually fundamental to the process of building software. Instead, it is
only relevant for compatibility with building certain specific compilers
and build tools. It can be safely ignored for all other packages.
</para>
<para>
The build process of certain compilers is written in such a way that the
compiler resulting from a single build can itself only produce binaries
for a single platform. The task specifying this single "target platform"
is thus pushed to build time of the compiler. The root cause of this
mistake is often that the compiler (which will be run on the host) and
the the standard library/runtime (which will be run on the target) are
built by a single build process.
</para>
<para>
There is no fundamental need to think about a single target ahead of
time like this. If the tool supports modular or pluggable backends, both
the need to specify the target at build time and the constraint of
having only a single target disappear. An example of such a tool is
LLVM.
</para>
<para>
Although the existence of a "target platfom" is arguably a historical
mistake, it is a common one: examples of tools that suffer from it are
GCC, Binutils, GHC and Autoconf. Nixpkgs tries to avoid sharing in the
mistake where possible. Still, because the concept of a target platform
is so ingrained, it is best to support it as is.
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
The exact schema these fields follow is a bit ill-defined due to a long and
convoluted evolution, but this is slowly being cleaned up. You can see
examples of ones used in practice in
<literal>lib.systems.examples</literal>; note how they are not all very
consistent. For now, here are few fields can count on them containing:
</para>
<variablelist>
<varlistentry>
<term><varname>system</varname>
</term>
<listitem>
<para>
This is a two-component shorthand for the platform. Examples of this
would be "x86_64-darwin" and "i686-linux"; see
<literal>lib.systems.doubles</literal> for more. This format isn't very
standard, but has built-in support in Nix, such as the
<varname>builtins.currentSystem</varname> impure string.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>config</varname>
</term>
<listitem>
<para>
This is a 3- or 4- component shorthand for the platform. Examples of
this would be "x86_64-unknown-linux-gnu" and "aarch64-apple-darwin14".
This is a standard format called the "LLVM target triple", as they are
pioneered by LLVM and traditionally just used for the
<varname>targetPlatform</varname>. This format is strictly more
informative than the "Nix host double", as the previous format could
analogously be termed. This needs a better name than
<varname>config</varname>!
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>parsed</varname>
</term>
<listitem>
<para>
This is a nix representation of a parsed LLVM target triple with
white-listed components. This can be specified directly, or actually
parsed from the <varname>config</varname>. [Technically, only one need
be specified and the others can be inferred, though the precision of
inference may not be very good.] See
<literal>lib.systems.parse</literal> for the exact representation.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>libc</varname>
</term>
<listitem>
<para>
This is a string identifying the standard C library used. Valid
identifiers include "glibc" for GNU libc, "libSystem" for Darwin's
Libsystem, and "uclibc" for µClibc. It should probably be refactored to
use the module system, like <varname>parse</varname>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>is*</varname>
</term>
<listitem>
<para>
These predicates are defined in <literal>lib.systems.inspect</literal>,
and slapped on every platform. They are superior to the ones in
<varname>stdenv</varname> as they force the user to be explicit about
which platform they are inspecting. Please use these instead of those.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>platform</varname>
</term>
<listitem>
<para>
This is, quite frankly, a dumping ground of ad-hoc settings (it's an
attribute set). See <literal>lib.systems.platforms</literal> for
examples—there's hopefully one in there that will work verbatim for
each platform that is working. Please help us triage these flags and
give them better homes!
</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>Specifying Dependencies</title>
<title>Specifying Dependencies</title>
<para>
In this section we explore the relationship between both runtime and
buildtime dependencies and the 3 Autoconf platforms.
</para>
<para>
A runtime dependency between 2 packages implies that between them both the
host and target platforms match. This is directly implied by the meaning of
"host platform" and "runtime dependency": The package dependency exists
while both packages are running on a single host platform.
</para>
<para>
A build time dependency, however, implies a shift in platforms between the
depending package and the depended-on package. The meaning of a build time
dependency is that to build the depending package we need to be able to run
the depended-on's package. The depending package's build platform is
therefore equal to the depended-on package's host platform. Analogously,
the depending package's host platform is equal to the depended-on package's
target platform.
</para>
<para>
In this manner, given the 3 platforms for one package, we can determine the
three platforms for all its transitive dependencies. This is the most
important guiding principle behind cross-compilation with Nixpkgs, and will
be called the <wordasword>sliding window principle</wordasword>.
</para>
<para>
Some examples will probably make this clearer. If a package is being built
with a <literal>(build, host, target)</literal> platform triple of
<literal>(foo, bar, bar)</literal>, then its build-time dependencies would
have a triple of <literal>(foo, foo, bar)</literal>, and <emphasis>those
packages'</emphasis> build-time dependencies would have triple of
<literal>(foo, foo, foo)</literal>. In other words, it should take two
"rounds" of following build-time dependency edges before one reaches a
fixed point where, by the sliding window principle, the platform triple no
longer changes. Indeed, this happens with cross compilation, where only
rounds of native dependencies starting with the second necessarily coincide
with native packages.
</para>
<note>
<para>
In this section we explore the relationship between both runtime and buildtime dependencies and the 3 Autoconf platforms.
The depending package's target platform is unconstrained by the sliding
window principle, which makes sense in that one can in principle build
cross compilers targeting arbitrary platforms.
</para>
</note>
<para>
How does this work in practice? Nixpkgs is now structured so that
build-time dependencies are taken from <varname>buildPackages</varname>,
whereas run-time dependencies are taken from the top level attribute set.
For example, <varname>buildPackages.gcc</varname> should be used at build
time, while <varname>gcc</varname> should be used at run time. Now, for
most of Nixpkgs's history, there was no <varname>buildPackages</varname>,
and most packages have not been refactored to use it explicitly. Instead,
one can use the six (<emphasis>gasp</emphasis>) attributes used for
specifying dependencies as documented in
<xref linkend="ssec-stdenv-dependencies"/>. We "splice" together the
run-time and build-time package sets with <varname>callPackage</varname>,
and then <varname>mkDerivation</varname> for each of four attributes pulls
the right derivation out. This splicing can be skipped when not cross
compiling as the package sets are the same, but is a bit slow for cross
compiling. Because of this, a best-of-both-worlds solution is in the works
with no splicing or explicit access of <varname>buildPackages</varname>
needed. For now, feel free to use either method.
</para>
<note>
<para>
A runtime dependency between 2 packages implies that between them both the host and target platforms match.
This is directly implied by the meaning of "host platform" and "runtime dependency":
The package dependency exists while both packages are running on a single host platform.
There is also a "backlink" <varname>targetPackages</varname>, yielding a
package set whose <varname>buildPackages</varname> is the current package
set. This is a hack, though, to accommodate compilers with lousy build
systems. Please do not use this unless you are absolutely sure you are
packaging such a compiler and there is no other way.
</para>
<para>
A build time dependency, however, implies a shift in platforms between the depending package and the depended-on package.
The meaning of a build time dependency is that to build the depending package we need to be able to run the depended-on's package.
The depending package's build platform is therefore equal to the depended-on package's host platform.
Analogously, the depending package's host platform is equal to the depended-on package's target platform.
</para>
<para>
In this manner, given the 3 platforms for one package, we can determine the three platforms for all its transitive dependencies.
This is the most important guiding principle behind cross-compilation with Nixpkgs, and will be called the <wordasword>sliding window principle</wordasword>.
</para>
<para>
Some examples will probably make this clearer.
If a package is being built with a <literal>(build, host, target)</literal> platform triple of <literal>(foo, bar, bar)</literal>, then its build-time dependencies would have a triple of <literal>(foo, foo, bar)</literal>, and <emphasis>those packages'</emphasis> build-time dependencies would have triple of <literal>(foo, foo, foo)</literal>.
In other words, it should take two "rounds" of following build-time dependency edges before one reaches a fixed point where, by the sliding window principle, the platform triple no longer changes.
Indeed, this happens with cross compilation, where only rounds of native dependencies starting with the second necessarily coincide with native packages.
</para>
<note><para>
The depending package's target platform is unconstrained by the sliding window principle, which makes sense in that one can in principle build cross compilers targeting arbitrary platforms.
</para></note>
<para>
How does this work in practice? Nixpkgs is now structured so that build-time dependencies are taken from <varname>buildPackages</varname>, whereas run-time dependencies are taken from the top level attribute set.
For example, <varname>buildPackages.gcc</varname> should be used at build time, while <varname>gcc</varname> should be used at run time.
Now, for most of Nixpkgs's history, there was no <varname>buildPackages</varname>, and most packages have not been refactored to use it explicitly.
Instead, one can use the six (<emphasis>gasp</emphasis>) attributes used for specifying dependencies as documented in <xref linkend="ssec-stdenv-dependencies"/>.
We "splice" together the run-time and build-time package sets with <varname>callPackage</varname>, and then <varname>mkDerivation</varname> for each of four attributes pulls the right derivation out.
This splicing can be skipped when not cross compiling as the package sets are the same, but is a bit slow for cross compiling.
Because of this, a best-of-both-worlds solution is in the works with no splicing or explicit access of <varname>buildPackages</varname> needed.
For now, feel free to use either method.
</para>
<note><para>
There is also a "backlink" <varname>targetPackages</varname>, yielding a package set whose <varname>buildPackages</varname> is the current package set.
This is a hack, though, to accommodate compilers with lousy build systems.
Please do not use this unless you are absolutely sure you are packaging such a compiler and there is no other way.
</para></note>
</note>
</section>
<section>
<title>Cross packagaing cookbook</title>
<para>
Some frequently problems when packaging for cross compilation are good to just spell and answer.
Ideally the information above is exhaustive, so this section cannot provide any new information,
but its ludicrous and cruel to expect everyone to spend effort working through the interaction of many features just to figure out the same answer to the same common problem.
Feel free to add to this list!
</para>
<qandaset>
<qandaentry>
<question><para>
What if my package's build system needs to build a C program to be run under the build environment?
</para></question>
<answer><para>
<programlisting>depsBuildBuild = [ buildPackages.stdenv.cc ];</programlisting>
Add it to your <function>mkDerivation</function> invocation.
</para></answer>
</qandaentry>
<qandaentry>
<question><para>
My package fails to find <command>ar</command>.
</para></question>
<answer><para>
Many packages assume that an unprefixed <command>ar</command> is available, but Nix doesn't provide one.
It only provides a prefixed one, just as it only does for all the other binutils programs.
It may be necessary to patch the package to fix the build system to use a prefixed `ar`.
</para></answer>
</qandaentry>
<qandaentry>
<question><para>
My package's testsuite needs to run host platform code.
</para></question>
<answer><para>
<programlisting>doCheck = stdenv.hostPlatform != stdenv.buildPlatfrom;</programlisting>
Add it to your <function>mkDerivation</function> invocation.
</para></answer>
</qandaentry>
</qandaset>
</section>
</section>
<title>Cross packagaing cookbook</title>
<para>
Some frequently problems when packaging for cross compilation are good to
just spell and answer. Ideally the information above is exhaustive, so this
section cannot provide any new information, but its ludicrous and cruel to
expect everyone to spend effort working through the interaction of many
features just to figure out the same answer to the same common problem.
Feel free to add to this list!
</para>
<qandaset>
<qandaentry>
<question>
<para>
What if my package's build system needs to build a C program to be run
under the build environment?
</para>
</question>
<answer>
<para>
<programlisting>depsBuildBuild = [ buildPackages.stdenv.cc ];</programlisting>
Add it to your <function>mkDerivation</function> invocation.
</para>
</answer>
</qandaentry>
<qandaentry>
<question>
<para>
My package fails to find <command>ar</command>.
</para>
</question>
<answer>
<para>
Many packages assume that an unprefixed <command>ar</command> is
available, but Nix doesn't provide one. It only provides a prefixed one,
just as it only does for all the other binutils programs. It may be
necessary to patch the package to fix the build system to use a prefixed
`ar`.
</para>
</answer>
</qandaentry>
<qandaentry>
<question>
<para>
My package's testsuite needs to run host platform code.
</para>
</question>
<answer>
<para>
<programlisting>doCheck = stdenv.hostPlatform != stdenv.buildPlatfrom;</programlisting>
Add it to your <function>mkDerivation</function> invocation.
</para>
</answer>
</qandaentry>
</qandaset>
</section>
</section>
<!--============================================================-->
<section xml:id="sec-cross-usage">
<section xml:id="sec-cross-usage">
<title>Cross-building packages</title>
<note><para>
More information needs to moved from the old wiki, especially <link xlink:href="https://nixos.org/wiki/CrossCompiling" />, for this section.
</para></note>
<note>
<para>
More information needs to moved from the old wiki, especially
<link xlink:href="https://nixos.org/wiki/CrossCompiling" />, for this
section.
</para>
</note>
<para>
Nixpkgs can be instantiated with <varname>localSystem</varname> alone, in which case there is no cross compiling and everything is built by and for that system,
or also with <varname>crossSystem</varname>, in which case packages run on the latter, but all building happens on the former.
Both parameters take the same schema as the 3 (build, host, and target) platforms defined in the previous section.
As mentioned above, <literal>lib.systems.examples</literal> has some platforms which are used as arguments for these parameters in practice.
You can use them programmatically, or on the command line: <programlisting>
Nixpkgs can be instantiated with <varname>localSystem</varname> alone, in
which case there is no cross compiling and everything is built by and for
that system, or also with <varname>crossSystem</varname>, in which case
packages run on the latter, but all building happens on the former. Both
parameters take the same schema as the 3 (build, host, and target) platforms
defined in the previous section. As mentioned above,
<literal>lib.systems.examples</literal> has some platforms which are used as
arguments for these parameters in practice. You can use them
programmatically, or on the command line:
<programlisting>
nix-build &lt;nixpkgs&gt; --arg crossSystem '(import &lt;nixpkgs/lib&gt;).systems.examples.fooBarBaz' -A whatever</programlisting>
</para>
<note>
<para>
Eventually we would like to make these platform examples an unnecessary convenience so that <programlisting>
<para>
Eventually we would like to make these platform examples an unnecessary
convenience so that
<programlisting>
nix-build &lt;nixpkgs&gt; --arg crossSystem.config '&lt;arch&gt;-&lt;os&gt;-&lt;vendor&gt;-&lt;abi&gt;' -A whatever</programlisting>
works in the vast majority of cases.
The problem today is dependencies on other sorts of configuration which aren't given proper defaults.
We rely on the examples to crudely to set those configuration parameters in some vaguely sane manner on the users behalf.
Issue <link xlink:href="https://github.com/NixOS/nixpkgs/issues/34274">#34274</link> tracks this inconvenience along with its root cause in crufty configuration options.
</para>
works in the vast majority of cases. The problem today is dependencies on
other sorts of configuration which aren't given proper defaults. We rely on
the examples to crudely to set those configuration parameters in some
vaguely sane manner on the users behalf. Issue
<link xlink:href="https://github.com/NixOS/nixpkgs/issues/34274">#34274</link>
tracks this inconvenience along with its root cause in crufty configuration
options.
</para>
</note>
<para>
While one is free to pass both parameters in full, there's a lot of logic to fill in missing fields.
As discussed in the previous section, only one of <varname>system</varname>, <varname>config</varname>, and <varname>parsed</varname> is needed to infer the other two.
Additionally, <varname>libc</varname> will be inferred from <varname>parse</varname>.
Finally, <literal>localSystem.system</literal> is also <emphasis>impurely</emphasis> inferred based on the platform evaluation occurs.
This means it is often not necessary to pass <varname>localSystem</varname> at all, as in the command-line example in the previous paragraph.
While one is free to pass both parameters in full, there's a lot of logic to
fill in missing fields. As discussed in the previous section, only one of
<varname>system</varname>, <varname>config</varname>, and
<varname>parsed</varname> is needed to infer the other two. Additionally,
<varname>libc</varname> will be inferred from <varname>parse</varname>.
Finally, <literal>localSystem.system</literal> is also
<emphasis>impurely</emphasis> inferred based on the platform evaluation
occurs. This means it is often not necessary to pass
<varname>localSystem</varname> at all, as in the command-line example in the
previous paragraph.
</para>
<note>
<para>
Many sources (manual, wiki, etc) probably mention passing <varname>system</varname>, <varname>platform</varname>, along with the optional <varname>crossSystem</varname> to nixpkgs:
<literal>import &lt;nixpkgs&gt; { system = ..; platform = ..; crossSystem = ..; }</literal>.
Passing those two instead of <varname>localSystem</varname> is still supported for compatibility, but is discouraged.
Indeed, much of the inference we do for these parameters is motivated by compatibility as much as convenience.
</para>
<para>
Many sources (manual, wiki, etc) probably mention passing
<varname>system</varname>, <varname>platform</varname>, along with the
optional <varname>crossSystem</varname> to nixpkgs: <literal>import
&lt;nixpkgs&gt; { system = ..; platform = ..; crossSystem = ..;
}</literal>. Passing those two instead of <varname>localSystem</varname> is
still supported for compatibility, but is discouraged. Indeed, much of the
inference we do for these parameters is motivated by compatibility as much
as convenience.
</para>
</note>
<para>
One would think that <varname>localSystem</varname> and <varname>crossSystem</varname> overlap horribly with the three <varname>*Platforms</varname> (<varname>buildPlatform</varname>, <varname>hostPlatform,</varname> and <varname>targetPlatform</varname>; see <varname>stage.nix</varname> or the manual).
Actually, those identifiers are purposefully not used here to draw a subtle but important distinction:
While the granularity of having 3 platforms is necessary to properly *build* packages, it is overkill for specifying the user's *intent* when making a build plan or package set.
A simple "build vs deploy" dichotomy is adequate: the sliding window principle described in the previous section shows how to interpolate between the these two "end points" to get the 3 platform triple for each bootstrapping stage.
That means for any package a given package set, even those not bound on the top level but only reachable via dependencies or <varname>buildPackages</varname>, the three platforms will be defined as one of <varname>localSystem</varname> or <varname>crossSystem</varname>, with the former replacing the latter as one traverses build-time dependencies.
A last simple difference then is <varname>crossSystem</varname> should be null when one doesn't want to cross-compile, while the <varname>*Platform</varname>s are always non-null.
<varname>localSystem</varname> is always non-null.
One would think that <varname>localSystem</varname> and
<varname>crossSystem</varname> overlap horribly with the three
<varname>*Platforms</varname> (<varname>buildPlatform</varname>,
<varname>hostPlatform,</varname> and <varname>targetPlatform</varname>; see
<varname>stage.nix</varname> or the manual). Actually, those identifiers are
purposefully not used here to draw a subtle but important distinction: While
the granularity of having 3 platforms is necessary to properly *build*
packages, it is overkill for specifying the user's *intent* when making a
build plan or package set. A simple "build vs deploy" dichotomy is adequate:
the sliding window principle described in the previous section shows how to
interpolate between the these two "end points" to get the 3 platform triple
for each bootstrapping stage. That means for any package a given package
set, even those not bound on the top level but only reachable via
dependencies or <varname>buildPackages</varname>, the three platforms will
be defined as one of <varname>localSystem</varname> or
<varname>crossSystem</varname>, with the former replacing the latter as one
traverses build-time dependencies. A last simple difference then is
<varname>crossSystem</varname> should be null when one doesn't want to
cross-compile, while the <varname>*Platform</varname>s are always non-null.
<varname>localSystem</varname> is always non-null.
</para>
</section>
</section>
<!--============================================================-->
<section xml:id="sec-cross-infra">
<section xml:id="sec-cross-infra">
<title>Cross-compilation infrastructure</title>
<para>To be written.</para>
<note><para>
If one explores nixpkgs, they will see derivations with names like <literal>gccCross</literal>.
Such <literal>*Cross</literal> derivations is a holdover from before we properly distinguished between the host and target platforms
—the derivation with "Cross" in the name covered the <literal>build = host != target</literal> case, while the other covered the <literal>host = target</literal>, with build platform the same or not based on whether one was using its <literal>.nativeDrv</literal> or <literal>.crossDrv</literal>.
This ugliness will disappear soon.
</para></note>
</section>
<para>
To be written.
</para>
<note>
<para>
If one explores nixpkgs, they will see derivations with names like
<literal>gccCross</literal>. Such <literal>*Cross</literal> derivations is
a holdover from before we properly distinguished between the host and
target platforms —the derivation with "Cross" in the name covered the
<literal>build = host != target</literal> case, while the other covered the
<literal>host = target</literal>, with build platform the same or not based
on whether one was using its <literal>.nativeDrv</literal> or
<literal>.crossDrv</literal>. This ugliness will disappear soon.
</para>
</note>
</section>
</chapter>

3
doc/default.nix
View File

@ -7,7 +7,7 @@ in
pkgs.stdenv.mkDerivation {
name = "nixpkgs-manual";
buildInputs = with pkgs; [ pandoc libxml2 libxslt zip jing ];
buildInputs = with pkgs; [ pandoc libxml2 libxslt zip jing xmlformat ];
src = ./.;
@ -18,6 +18,7 @@ pkgs.stdenv.mkDerivation {
HIGHLIGHTJS = pkgs.documentation-highlighter;
XSL = "${pkgs.docbook5_xsl}/xml/xsl";
RNG = "${pkgs.docbook5}/xml/rng/docbook/docbook.rng";
XMLFORMAT_CONFIG = ../nixos/doc/xmlformat.conf;
xsltFlags = lib.concatStringsSep " " [
"--param section.autolabel 1"
"--param section.label.includes.component.label 1"

1097
doc/functions.xml
View File

File diff suppressed because it is too large Load Diff

520
doc/languages-frameworks/beam.xml
View File

@ -1,124 +1,137 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-beam">
<title>BEAM Languages (Erlang, Elixir &amp; LFE)</title>
<title>BEAM Languages (Erlang, Elixir &amp; LFE)</title>
<section xml:id="beam-introduction">
<title>Introduction</title>
<para>
In this document and related Nix expressions, we use the term,
<emphasis>BEAM</emphasis>, to describe the environment. BEAM is the name
of the Erlang Virtual Machine and, as far as we're concerned, from a
packaging perspective, all languages that run on the BEAM are
interchangeable. That which varies, like the build system, is transparent
to users of any given BEAM package, so we make no distinction.
</para>
</section>
<section xml:id="beam-structure">
<title>Structure</title>
<para>
All BEAM-related expressions are available via the top-level
<literal>beam</literal> attribute, which includes:
</para>
<itemizedlist>
<listitem>
<para>
<literal>interpreters</literal>: a set of compilers running on the
BEAM, including multiple Erlang/OTP versions
(<literal>beam.interpreters.erlangR19</literal>, etc), Elixir
(<literal>beam.interpreters.elixir</literal>) and LFE
(<literal>beam.interpreters.lfe</literal>).
</para>
</listitem>
<listitem>
<para>
<literal>packages</literal>: a set of package sets, each compiled with
a specific Erlang/OTP version, e.g.
<literal>beam.packages.erlangR19</literal>.
</para>
</listitem>
</itemizedlist>
<para>
The default Erlang compiler, defined by
<literal>beam.interpreters.erlang</literal>, is aliased as
<literal>erlang</literal>. The default BEAM package set is defined by
<literal>beam.packages.erlang</literal> and aliased at the top level as
<literal>beamPackages</literal>.
</para>
<para>
To create a package set built with a custom Erlang version, use the
lambda, <literal>beam.packagesWith</literal>, which accepts an Erlang/OTP
derivation and produces a package set similar to
<literal>beam.packages.erlang</literal>.
</para>
<para>
Many Erlang/OTP distributions available in
<literal>beam.interpreters</literal> have versions with ODBC and/or Java
enabled. For example, there's
<literal>beam.interpreters.erlangR19_odbc_javac</literal>, which
corresponds to <literal>beam.interpreters.erlangR19</literal>.
</para>
<para xml:id="erlang-call-package">
We also provide the lambda,
<literal>beam.packages.erlang.callPackage</literal>, which simplifies
writing BEAM package definitions by injecting all packages from
<literal>beam.packages.erlang</literal> into the top-level context.
</para>
</section>
<section xml:id="build-tools">
<title>Build Tools</title>
<section xml:id="build-tools-rebar3">
<title>Rebar3</title>
<para>
By default, Rebar3 wants to manage its own dependencies. This is perfectly
acceptable in the normal, non-Nix setup, but in the Nix world, it is not.
To rectify this, we provide two versions of Rebar3:
<itemizedlist>
<listitem>
<para>
<literal>rebar3</literal>: patched to remove the ability to download
anything. When not running it via <literal>nix-shell</literal> or
<literal>nix-build</literal>, it's probably not going to work as
desired.
</para>
</listitem>
<listitem>
<para>
<literal>rebar3-open</literal>: the normal, unmodified Rebar3. It
should work exactly as would any other version of Rebar3. Any Erlang
package should rely on <literal>rebar3</literal> instead. See <xref
linkend="rebar3-packages"/>.
</para>
</listitem>
</itemizedlist>
</para>
</section>
<section xml:id="build-tools-other">
<title>Mix &amp; Erlang.mk</title>
<para>
Both Mix and Erlang.mk work exactly as expected. There is a bootstrap
process that needs to be run for both, however, which is supported by the
<literal>buildMix</literal> and <literal>buildErlangMk</literal>
derivations, respectively.
</para>
</section>
</section>
<section xml:id="beam-introduction">
<title>Introduction</title>
<section xml:id="how-to-install-beam-packages">
<title>How to Install BEAM Packages</title>
<para>
BEAM packages are not registered at the top level, simply because they are
not relevant to the vast majority of Nix users. They are installable using
the <literal>beam.packages.erlang</literal> attribute set (aliased as
<literal>beamPackages</literal>), which points to packages built by the
default Erlang/OTP version in Nixpkgs, as defined by
<literal>beam.interpreters.erlang</literal>.
In this document and related Nix expressions, we use the term,
<emphasis>BEAM</emphasis>, to describe the environment. BEAM is the name of
the Erlang Virtual Machine and, as far as we're concerned, from a packaging
perspective, all languages that run on the BEAM are interchangeable. That
which varies, like the build system, is transparent to users of any given
BEAM package, so we make no distinction.
</para>
</section>
To list the available packages in
<literal>beamPackages</literal>, use the following command:
<section xml:id="beam-structure">
<title>Structure</title>
<para>
All BEAM-related expressions are available via the top-level
<literal>beam</literal> attribute, which includes:
</para>
<programlisting>
<itemizedlist>
<listitem>
<para>
<literal>interpreters</literal>: a set of compilers running on the BEAM,
including multiple Erlang/OTP versions
(<literal>beam.interpreters.erlangR19</literal>, etc), Elixir
(<literal>beam.interpreters.elixir</literal>) and LFE
(<literal>beam.interpreters.lfe</literal>).
</para>
</listitem>
<listitem>
<para>
<literal>packages</literal>: a set of package sets, each compiled with a
specific Erlang/OTP version, e.g.
<literal>beam.packages.erlangR19</literal>.
</para>
</listitem>
</itemizedlist>
<para>
The default Erlang compiler, defined by
<literal>beam.interpreters.erlang</literal>, is aliased as
<literal>erlang</literal>. The default BEAM package set is defined by
<literal>beam.packages.erlang</literal> and aliased at the top level as
<literal>beamPackages</literal>.
</para>
<para>
To create a package set built with a custom Erlang version, use the lambda,
<literal>beam.packagesWith</literal>, which accepts an Erlang/OTP derivation
and produces a package set similar to
<literal>beam.packages.erlang</literal>.
</para>
<para>
Many Erlang/OTP distributions available in
<literal>beam.interpreters</literal> have versions with ODBC and/or Java
enabled. For example, there's
<literal>beam.interpreters.erlangR19_odbc_javac</literal>, which corresponds
to <literal>beam.interpreters.erlangR19</literal>.
</para>
<para xml:id="erlang-call-package">
We also provide the lambda,
<literal>beam.packages.erlang.callPackage</literal>, which simplifies
writing BEAM package definitions by injecting all packages from
<literal>beam.packages.erlang</literal> into the top-level context.
</para>
</section>
<section xml:id="build-tools">
<title>Build Tools</title>
<section xml:id="build-tools-rebar3">
<title>Rebar3</title>
<para>
By default, Rebar3 wants to manage its own dependencies. This is perfectly
acceptable in the normal, non-Nix setup, but in the Nix world, it is not.
To rectify this, we provide two versions of Rebar3:
<itemizedlist>
<listitem>
<para>
<literal>rebar3</literal>: patched to remove the ability to download
anything. When not running it via <literal>nix-shell</literal> or
<literal>nix-build</literal>, it's probably not going to work as
desired.
</para>
</listitem>
<listitem>
<para>
<literal>rebar3-open</literal>: the normal, unmodified Rebar3. It should
work exactly as would any other version of Rebar3. Any Erlang package
should rely on <literal>rebar3</literal> instead. See
<xref
linkend="rebar3-packages"/>.
</para>
</listitem>
</itemizedlist>
</para>
</section>
<section xml:id="build-tools-other">
<title>Mix &amp; Erlang.mk</title>
<para>
Both Mix and Erlang.mk work exactly as expected. There is a bootstrap
process that needs to be run for both, however, which is supported by the
<literal>buildMix</literal> and <literal>buildErlangMk</literal>
derivations, respectively.
</para>
</section>
</section>
<section xml:id="how-to-install-beam-packages">
<title>How to Install BEAM Packages</title>
<para>
BEAM packages are not registered at the top level, simply because they are
not relevant to the vast majority of Nix users. They are installable using
the <literal>beam.packages.erlang</literal> attribute set (aliased as
<literal>beamPackages</literal>), which points to packages built by the
default Erlang/OTP version in Nixpkgs, as defined by
<literal>beam.interpreters.erlang</literal>. To list the available packages
in <literal>beamPackages</literal>, use the following command:
</para>
<programlisting>
$ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -qaP -A beamPackages
beamPackages.esqlite esqlite-0.2.1
beamPackages.goldrush goldrush-0.1.7
@ -128,34 +141,43 @@ beamPackages.lager lager-3.0.2
beamPackages.meck meck-0.8.3
beamPackages.rebar3-pc pc-1.1.0
</programlisting>
<para>
To install any of those packages into your profile, refer to them by their
attribute path (first column):
To install any of those packages into your profile, refer to them by their
attribute path (first column):
</para>
<programlisting>
<programlisting>
$ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.ibrowse
</programlisting>
<para>
The attribute path of any BEAM package corresponds to the name of that
particular package in <link xlink:href="https://hex.pm">Hex</link> or its
OTP Application/Release name.
The attribute path of any BEAM package corresponds to the name of that
particular package in <link xlink:href="https://hex.pm">Hex</link> or its
OTP Application/Release name.
</para>
</section>
<section xml:id="packaging-beam-applications">
</section>
<section xml:id="packaging-beam-applications">
<title>Packaging BEAM Applications</title>
<section xml:id="packaging-erlang-applications">
<title>Erlang Applications</title>
<section xml:id="rebar3-packages">
<title>Rebar3 Packages</title>
<para>
The Nix function, <literal>buildRebar3</literal>, defined in
<literal>beam.packages.erlang.buildRebar3</literal> and aliased at the
top level, can be used to build a derivation that understands how to
build a Rebar3 project. For example, we can build <link
xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link> as
follows:
</para>
<programlisting>
<title>Erlang Applications</title>
<section xml:id="rebar3-packages">
<title>Rebar3 Packages</title>
<para>
The Nix function, <literal>buildRebar3</literal>, defined in
<literal>beam.packages.erlang.buildRebar3</literal> and aliased at the top
level, can be used to build a derivation that understands how to build a
Rebar3 project. For example, we can build
<link
xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link>
as follows:
</para>
<programlisting>
{ stdenv, fetchFromGitHub, buildRebar3, ibrowse, jsx, erlware_commons }:
buildRebar3 rec {
@ -172,33 +194,40 @@ $ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.ibrowse
beamDeps = [ ibrowse jsx erlware_commons ];
}
</programlisting>
<para>
Such derivations are callable with
<literal>beam.packages.erlang.callPackage</literal> (see <xref
linkend="erlang-call-package"/>). To call this package using the normal
<literal>callPackage</literal>, refer to dependency packages via
<literal>beamPackages</literal>, e.g.
<literal>beamPackages.ibrowse</literal>.
</para>
<para>
Notably, <literal>buildRebar3</literal> includes
<literal>beamDeps</literal>, while
<literal>stdenv.mkDerivation</literal> does not. BEAM dependencies added
there will be correctly handled by the system.
</para>
<para>
If a package needs to compile native code via Rebar3's port compilation
mechanism, add <literal>compilePort = true;</literal> to the derivation.
</para>
</section>
<section xml:id="erlang-mk-packages">
<title>Erlang.mk Packages</title>
<para>
Erlang.mk functions similarly to Rebar3, except we use
<literal>buildErlangMk</literal> instead of
<literal>buildRebar3</literal>.
</para>
<programlisting>
<para>
Such derivations are callable with
<literal>beam.packages.erlang.callPackage</literal> (see
<xref
linkend="erlang-call-package"/>). To call this package using
the normal <literal>callPackage</literal>, refer to dependency packages
via <literal>beamPackages</literal>, e.g.
<literal>beamPackages.ibrowse</literal>.
</para>
<para>
Notably, <literal>buildRebar3</literal> includes
<literal>beamDeps</literal>, while <literal>stdenv.mkDerivation</literal>
does not. BEAM dependencies added there will be correctly handled by the
system.
</para>
<para>
If a package needs to compile native code via Rebar3's port compilation
mechanism, add <literal>compilePort = true;</literal> to the derivation.
</para>
</section>
<section xml:id="erlang-mk-packages">
<title>Erlang.mk Packages</title>
<para>
Erlang.mk functions similarly to Rebar3, except we use
<literal>buildErlangMk</literal> instead of
<literal>buildRebar3</literal>.
</para>
<programlisting>
{ buildErlangMk, fetchHex, cowlib, ranch }:
buildErlangMk {
@ -222,14 +251,17 @@ $ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.ibrowse
};
}
</programlisting>
</section>
<section xml:id="mix-packages">
<title>Mix Packages</title>
<para>
Mix functions similarly to Rebar3, except we use
<literal>buildMix</literal> instead of <literal>buildRebar3</literal>.
</para>
<programlisting>
</section>
<section xml:id="mix-packages">
<title>Mix Packages</title>
<para>
Mix functions similarly to Rebar3, except we use
<literal>buildMix</literal> instead of <literal>buildRebar3</literal>.
</para>
<programlisting>
{ buildMix, fetchHex, plug, absinthe }:
buildMix {
@ -253,10 +285,12 @@ $ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.ibrowse
};
}
</programlisting>
<para>
Alternatively, we can use <literal>buildHex</literal> as a shortcut:
</para>
<programlisting>
<para>
Alternatively, we can use <literal>buildHex</literal> as a shortcut:
</para>
<programlisting>
{ buildHex, buildMix, plug, absinthe }:
buildHex {
@ -278,21 +312,25 @@ $ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.ibrowse
};
}
</programlisting>
</section>
</section>
</section>
</section>
<section xml:id="how-to-develop">
</section>
<section xml:id="how-to-develop">
<title>How to Develop</title>
<section xml:id="accessing-an-environment">
<title>Accessing an Environment</title>
<para>
Often, we simply want to access a valid environment that contains a
specific package and its dependencies. We can accomplish that with the
<literal>env</literal> attribute of a derivation. For example, let's say
we want to access an Erlang REPL with <literal>ibrowse</literal> loaded
up. We could do the following:
</para>
<programlisting>
<title>Accessing an Environment</title>
<para>
Often, we simply want to access a valid environment that contains a
specific package and its dependencies. We can accomplish that with the
<literal>env</literal> attribute of a derivation. For example, let's say we
want to access an Erlang REPL with <literal>ibrowse</literal> loaded up. We
could do the following:
</para>
<programlisting>
$ nix-shell -A beamPackages.ibrowse.env --run "erl"
Erlang/OTP 18 [erts-7.0] [source] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false]
@ -333,22 +371,25 @@ $ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.ibrowse
ok
2>
</programlisting>
<para>
Notice the <literal>-A beamPackages.ibrowse.env</literal>. That is the key
to this functionality.
</para>
<para>
Notice the <literal>-A beamPackages.ibrowse.env</literal>. That is the key
to this functionality.
</para>
</section>
<section xml:id="creating-a-shell">
<title>Creating a Shell</title>
<para>
Getting access to an environment often isn't enough to do real
development. Usually, we need to create a <literal>shell.nix</literal>
file and do our development inside of the environment specified therein.
This file looks a lot like the packaging described above, except that
<literal>src</literal> points to the project root and we call the package
directly.
</para>
<programlisting>
<title>Creating a Shell</title>
<para>
Getting access to an environment often isn't enough to do real development.
Usually, we need to create a <literal>shell.nix</literal> file and do our
development inside of the environment specified therein. This file looks a
lot like the packaging described above, except that <literal>src</literal>
points to the project root and we call the package directly.
</para>
<programlisting>
{ pkgs ? import &quot;&lt;nixpkgs&quot;&gt; {} }:
with pkgs;
@ -368,13 +409,16 @@ in
drv
</programlisting>
<section xml:id="building-in-a-shell">
<section xml:id="building-in-a-shell">
<title>Building in a Shell (for Mix Projects)</title>
<para>
We can leverage the support of the derivation, irrespective of the build
derivation, by calling the commands themselves.
We can leverage the support of the derivation, irrespective of the build
derivation, by calling the commands themselves.
</para>
<programlisting>
<programlisting>
# =============================================================================
# Variables
# =============================================================================
@ -431,44 +475,54 @@ analyze: build plt
$(NIX_SHELL) --run "mix dialyzer --no-compile"
</programlisting>
<para>
Using a <literal>shell.nix</literal> as described (see <xref
Using a <literal>shell.nix</literal> as described (see
<xref
linkend="creating-a-shell"/>) should just work. Aside from
<literal>test</literal>, <literal>plt</literal>, and
<literal>analyze</literal>, the Make targets work just fine for all of the
build derivations.
<literal>test</literal>, <literal>plt</literal>, and
<literal>analyze</literal>, the Make targets work just fine for all of the
build derivations.
</para>
</section>
</section>
</section>
</section>
<section xml:id="generating-packages-from-hex-with-hex2nix">
</section>
<section xml:id="generating-packages-from-hex-with-hex2nix">
<title>Generating Packages from Hex with <literal>hex2nix</literal></title>
<para>
Updating the <link xlink:href="https://hex.pm">Hex</link> package set
requires <link
xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link>. Given the
path to the Erlang modules (usually
<literal>pkgs/development/erlang-modules</literal>), it will dump a file
called <literal>hex-packages.nix</literal>, containing all the packages that
use a recognized build system in <link
xlink:href="https://hex.pm">Hex</link>. It can't be determined, however,
whether every package is buildable.
</para>
<para>
To make life easier for our users, try to build every <link
xlink:href="https://hex.pm">Hex</link> package and remove those that fail.
To do that, simply run the following command in the root of your
<literal>nixpkgs</literal> repository:
</para>
<programlisting>
Updating the <link xlink:href="https://hex.pm">Hex</link> package set
requires
<link
xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link>.
Given the path to the Erlang modules (usually
<literal>pkgs/development/erlang-modules</literal>), it will dump a file
called <literal>hex-packages.nix</literal>, containing all the packages that
use a recognized build system in
<link
xlink:href="https://hex.pm">Hex</link>. It can't be determined,
however, whether every package is buildable.
</para>
<para>
To make life easier for our users, try to build every
<link
xlink:href="https://hex.pm">Hex</link> package and remove those
that fail. To do that, simply run the following command in the root of your
<literal>nixpkgs</literal> repository:
</para>
<programlisting>
$ nix-build -A beamPackages
</programlisting>
<para>
That will attempt to build every package in
<literal>beamPackages</literal>. Then manually remove those that fail.
Hopefully, someone will improve <link
xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link> in the
future to automate the process.
</para>
</section>
<para>
That will attempt to build every package in <literal>beamPackages</literal>.
Then manually remove those that fail. Hopefully, someone will improve
<link
xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link>
in the future to automate the process.
</para>
</section>
</section>

279
doc/languages-frameworks/bower.xml
View File

@ -1,40 +1,37 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-bower">
<title>Bower</title>
<title>Bower</title>
<para>
<link xlink:href="http://bower.io">Bower</link> is a package manager for web
site front-end components. Bower packages (comprising of build artefacts and
sometimes sources) are stored in <command>git</command> repositories,
typically on Github. The package registry is run by the Bower team with
package metadata coming from the <filename>bower.json</filename> file within
each package.
</para>
<para>
<link xlink:href="http://bower.io">Bower</link> is a package manager
for web site front-end components. Bower packages (comprising of
build artefacts and sometimes sources) are stored in
<command>git</command> repositories, typically on Github. The
package registry is run by the Bower team with package metadata
coming from the <filename>bower.json</filename> file within each
package.
</para>
<para>
The end result of running Bower is a <filename>bower_components</filename>
directory which can be included in the web app's build process.
</para>
<para>
The end result of running Bower is a
<filename>bower_components</filename> directory which can be included
in the web app's build process.
</para>
<para>
<para>
Bower can be run interactively, by installing
<varname>nodePackages.bower</varname>. More interestingly, the Bower
components can be declared in a Nix derivation, with the help of
<varname>nodePackages.bower2nix</varname>.
</para>
</para>
<section xml:id="ssec-bower2nix-usage">
<section xml:id="ssec-bower2nix-usage">
<title><command>bower2nix</command> usage</title>
<para>
Suppose you have a <filename>bower.json</filename> with the following contents:
<example xml:id="ex-bowerJson"><title><filename>bower.json</filename></title>
<para>
Suppose you have a <filename>bower.json</filename> with the following
contents:
<example xml:id="ex-bowerJson">
<title><filename>bower.json</filename></title>
<programlisting language="json">
<![CDATA[{
"name": "my-web-app",
@ -44,14 +41,12 @@
}
}]]>
</programlisting>
</example>
</para>
<para>
Running <command>bower2nix</command> will produce something like the
following output:
</example>
</para>
<para>
Running <command>bower2nix</command> will produce something like the
following output:
<programlisting language="nix">
<![CDATA[{ fetchbower, buildEnv }:
buildEnv { name = "bower-env"; ignoreCollisions = true; paths = [
@ -60,31 +55,31 @@ buildEnv { name = "bower-env"; ignoreCollisions = true; paths = [
(fetchbower "jquery" "2.2.2" "1.9.1 - 2" "10sp5h98sqwk90y4k6hbdviwqzvzwqf47r3r51pakch5ii2y7js1")
]; }]]>
</programlisting>
</para>
<para>
Using the <command>bower2nix</command> command line arguments, the
output can be redirected to a file. A name like
<filename>bower-packages.nix</filename> would be fine.
</para>
<para>
The resulting derivation is a union of all the downloaded Bower
packages (and their dependencies). To use it, they still need to be
linked together by Bower, which is where
<varname>buildBowerComponents</varname> is useful.
</para>
</section>
<section xml:id="ssec-build-bower-components"><title><varname>buildBowerComponents</varname> function</title>
</para>
<para>
The function is implemented in <link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/bower-modules/generic/default.nix">
<filename>pkgs/development/bower-modules/generic/default.nix</filename></link>.
Example usage:
Using the <command>bower2nix</command> command line arguments, the output
can be redirected to a file. A name like
<filename>bower-packages.nix</filename> would be fine.
</para>
<example xml:id="ex-buildBowerComponents"><title>buildBowerComponents</title>
<para>
The resulting derivation is a union of all the downloaded Bower packages
(and their dependencies). To use it, they still need to be linked together
by Bower, which is where <varname>buildBowerComponents</varname> is useful.
</para>
</section>
<section xml:id="ssec-build-bower-components">
<title><varname>buildBowerComponents</varname> function</title>
<para>
The function is implemented in
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/bower-modules/generic/default.nix">
<filename>pkgs/development/bower-modules/generic/default.nix</filename></link>.
Example usage:
<example xml:id="ex-buildBowerComponents">
<title>buildBowerComponents</title>
<programlisting language="nix">
bowerComponents = buildBowerComponents {
name = "my-web-app";
@ -92,42 +87,42 @@ bowerComponents = buildBowerComponents {
src = myWebApp; <co xml:id="ex-buildBowerComponents-2" />
};
</programlisting>
</example>
</example>
</para>
<para>
In <xref linkend="ex-buildBowerComponents" />, the following arguments
are of special significance to the function:
<para>
In <xref linkend="ex-buildBowerComponents" />, the following arguments are
of special significance to the function:
<calloutlist>
<callout arearefs="ex-buildBowerComponents-1">
<para>
<varname>generated</varname> specifies the file which was created by
<command>bower2nix</command>.
</para>
</callout>
<callout arearefs="ex-buildBowerComponents-2">
<para>
<varname>src</varname> is your project's sources. It needs to contain a
<filename>bower.json</filename> file.
</para>
</callout>
</calloutlist>
</para>
<calloutlist>
<callout arearefs="ex-buildBowerComponents-1">
<para>
<varname>generated</varname> specifies the file which was created by <command>bower2nix</command>.
</para>
</callout>
<para>
<varname>buildBowerComponents</varname> will run Bower to link together the
output of <command>bower2nix</command>, resulting in a
<filename>bower_components</filename> directory which can be used.
</para>
<callout arearefs="ex-buildBowerComponents-2">
<para>
<varname>src</varname> is your project's sources. It needs to
contain a <filename>bower.json</filename> file.
</para>
</callout>
</calloutlist>
</para>
<para>
Here is an example of a web frontend build process using
<command>gulp</command>. You might use <command>grunt</command>, or anything
else.
</para>
<para>
<varname>buildBowerComponents</varname> will run Bower to link
together the output of <command>bower2nix</command>, resulting in a
<filename>bower_components</filename> directory which can be used.
</para>
<para>
Here is an example of a web frontend build process using
<command>gulp</command>. You might use <command>grunt</command>, or
anything else.
</para>
<example xml:id="ex-bowerGulpFile"><title>Example build script (<filename>gulpfile.js</filename>)</title>
<example xml:id="ex-bowerGulpFile">
<title>Example build script (<filename>gulpfile.js</filename>)</title>
<programlisting language="javascript">
<![CDATA[var gulp = require('gulp');
@ -142,10 +137,10 @@ gulp.task('build', [], function () {
.pipe(gulp.dest("./gulpdist/"));
});]]>
</programlisting>
</example>
</example>
<example xml:id="ex-buildBowerComponentsDefaultNix">
<title>Full example — <filename>default.nix</filename></title>
<example xml:id="ex-buildBowerComponentsDefaultNix">
<title>Full example — <filename>default.nix</filename></title>
<programlisting language="nix">
{ myWebApp ? { outPath = ./.; name = "myWebApp"; }
, pkgs ? import &lt;nixpkgs&gt; {}
@ -172,73 +167,63 @@ pkgs.stdenv.mkDerivation {
installPhase = "mv gulpdist $out";
}
</programlisting>
</example>
</example>
<para>
A few notes about <xref linkend="ex-buildBowerComponentsDefaultNix" />:
<calloutlist>
<callout arearefs="ex-buildBowerComponentsDefault-1">
<para>
The result of <varname>buildBowerComponents</varname> is an
input to the frontend build.
</para>
</callout>
<callout arearefs="ex-buildBowerComponentsDefault-2">
<para>
Whether to symlink or copy the
<filename>bower_components</filename> directory depends on the
build tool in use. In this case a copy is used to avoid
<command>gulp</command> silliness with permissions.
</para>
</callout>
<callout arearefs="ex-buildBowerComponentsDefault-3">
<para>
<command>gulp</command> requires <varname>HOME</varname> to
refer to a writeable directory.
</para>
</callout>
<callout arearefs="ex-buildBowerComponentsDefault-4">
<para>
<para>
A few notes about <xref linkend="ex-buildBowerComponentsDefaultNix" />:
<calloutlist>
<callout arearefs="ex-buildBowerComponentsDefault-1">
<para>
The result of <varname>buildBowerComponents</varname> is an input to the
frontend build.
</para>
</callout>
<callout arearefs="ex-buildBowerComponentsDefault-2">
<para>
Whether to symlink or copy the <filename>bower_components</filename>
directory depends on the build tool in use. In this case a copy is used
to avoid <command>gulp</command> silliness with permissions.
</para>
</callout>
<callout arearefs="ex-buildBowerComponentsDefault-3">
<para>
<command>gulp</command> requires <varname>HOME</varname> to refer to a
writeable directory.
</para>
</callout>
<callout arearefs="ex-buildBowerComponentsDefault-4">
<para>
The actual build command. Other tools could be used.
</para>
</callout>
</calloutlist>
</para>
</section>
</para>
</callout>
</calloutlist>
</para>
</section>
<section xml:id="ssec-bower2nix-troubleshooting">
<section xml:id="ssec-bower2nix-troubleshooting">
<title>Troubleshooting</title>
<variablelist>
<varlistentry>
<term>
<literal>ENOCACHE</literal> errors from
<variablelist>
<varlistentry>
<term><literal>ENOCACHE</literal> errors from
<varname>buildBowerComponents</varname>
</term>
<listitem>
<para>
This means that Bower was looking for a package version which
doesn't exist in the generated
<filename>bower-packages.nix</filename>.
</para>
<para>
If <filename>bower.json</filename> has been updated, then run
<command>bower2nix</command> again.
</para>
<para>
It could also be a bug in <command>bower2nix</command> or
<command>fetchbower</command>. If possible, try reformulating
the version specification in <filename>bower.json</filename>.
</para>
<para>
This means that Bower was looking for a package version which doesn't
exist in the generated <filename>bower-packages.nix</filename>.
</para>
<para>
If <filename>bower.json</filename> has been updated, then run
<command>bower2nix</command> again.
</para>
<para>
It could also be a bug in <command>bower2nix</command> or
<command>fetchbower</command>. If possible, try reformulating the version
specification in <filename>bower.json</filename>.
</para>
</listitem>
</varlistentry>
</variablelist>
</section>
</varlistentry>
</variablelist>
</section>
</section>

60
doc/languages-frameworks/coq.xml
View File

@ -1,36 +1,38 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-coq">
<title>Coq</title>
<title>Coq</title>
<para>
Coq libraries should be installed in
<literal>$(out)/lib/coq/${coq.coq-version}/user-contrib/</literal>.
Such directories are automatically added to the
<literal>$COQPATH</literal> environment variable by the hook defined
in the Coq derivation.
</para>
<para>
Some libraries require OCaml and sometimes also Camlp5 or findlib.
The exact versions that were used to build Coq are saved in the
<literal>coq.ocaml</literal> and <literal>coq.camlp5</literal>
and <literal>coq.findlib</literal> attributes.
</para>
<para>
Coq libraries may be compatible with some specific versions of Coq only.
The <literal>compatibleCoqVersions</literal> attribute is used to
precisely select those versions of Coq that are compatible with this
derivation.
</para>
<para>
Here is a simple package example. It is a pure Coq library, thus it
depends on Coq. It builds on the Mathematical Components library, thus it
also takes <literal>mathcomp</literal> as <literal>buildInputs</literal>.
Its <literal>Makefile</literal> has been generated using
<literal>coq_makefile</literal> so we only have to
set the <literal>$COQLIB</literal> variable at install time.
</para>
<programlisting>
<para>
Coq libraries should be installed in
<literal>$(out)/lib/coq/${coq.coq-version}/user-contrib/</literal>. Such
directories are automatically added to the <literal>$COQPATH</literal>
environment variable by the hook defined in the Coq derivation.
</para>
<para>
Some libraries require OCaml and sometimes also Camlp5 or findlib. The exact
versions that were used to build Coq are saved in the
<literal>coq.ocaml</literal> and <literal>coq.camlp5</literal> and
<literal>coq.findlib</literal> attributes.
</para>
<para>
Coq libraries may be compatible with some specific versions of Coq only. The
<literal>compatibleCoqVersions</literal> attribute is used to precisely
select those versions of Coq that are compatible with this derivation.
</para>
<para>
Here is a simple package example. It is a pure Coq library, thus it depends
on Coq. It builds on the Mathematical Components library, thus it also takes
<literal>mathcomp</literal> as <literal>buildInputs</literal>. Its
<literal>Makefile</literal> has been generated using
<literal>coq_makefile</literal> so we only have to set the
<literal>$COQLIB</literal> variable at install time.
</para>
<programlisting>
{ stdenv, fetchFromGitHub, coq, mathcomp }:
stdenv.mkDerivation rec {

164
doc/languages-frameworks/go.xml
View File

@ -1,14 +1,14 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-go">
<title>Go</title>
<title>Go</title>
<para>
The function <varname>buildGoPackage</varname> builds standard Go programs.
</para>
<para>The function <varname>buildGoPackage</varname> builds
standard Go programs.
</para>
<example xml:id='ex-buildGoPackage'><title>buildGoPackage</title>
<example xml:id='ex-buildGoPackage'>
<title>buildGoPackage</title>
<programlisting>
deis = buildGoPackage rec {
name = "deis-${version}";
@ -29,55 +29,56 @@ deis = buildGoPackage rec {
buildFlags = "--tags release"; <co xml:id='ex-buildGoPackage-4' />
}
</programlisting>
</example>
</example>
<para><xref linkend='ex-buildGoPackage'/> is an example expression using buildGoPackage,
the following arguments are of special significance to the function:
<calloutlist>
<callout arearefs='ex-buildGoPackage-1'>
<para>
<xref linkend='ex-buildGoPackage'/> is an example expression using
buildGoPackage, the following arguments are of special significance to the
function:
<calloutlist>
<callout arearefs='ex-buildGoPackage-1'>
<para>
<varname>goPackagePath</varname> specifies the package's canonical Go import path.
<varname>goPackagePath</varname> specifies the package's canonical Go
import path.
</para>
</callout>
<callout arearefs='ex-buildGoPackage-2'>
</callout>
<callout arearefs='ex-buildGoPackage-2'>
<para>
<varname>subPackages</varname> limits the builder from building child packages that
have not been listed. If <varname>subPackages</varname> is not specified, all child
packages will be built.
<varname>subPackages</varname> limits the builder from building child
packages that have not been listed. If <varname>subPackages</varname> is
not specified, all child packages will be built.
</para>
<para>
In this example only <literal>github.com/deis/deis/client</literal> will be built.
In this example only <literal>github.com/deis/deis/client</literal> will
be built.
</para>
</callout>
<callout arearefs='ex-buildGoPackage-3'>
</callout>
<callout arearefs='ex-buildGoPackage-3'>
<para>
<varname>goDeps</varname> is where the Go dependencies of a Go program are listed
as a list of package source identified by Go import path.
It could be imported as a separate <varname>deps.nix</varname> file for
readability. The dependency data structure is described below.
<varname>goDeps</varname> is where the Go dependencies of a Go program are
listed as a list of package source identified by Go import path. It could
be imported as a separate <varname>deps.nix</varname> file for
readability. The dependency data structure is described below.
</para>
</callout>
<callout arearefs='ex-buildGoPackage-4'>
</callout>
<callout arearefs='ex-buildGoPackage-4'>
<para>
<varname>buildFlags</varname> is a list of flags passed to the go build command.
<varname>buildFlags</varname> is a list of flags passed to the go build
command.
</para>
</callout>
</callout>
</calloutlist>
</para>
</calloutlist>
<para>
The <varname>goDeps</varname> attribute can be imported from a separate
<varname>nix</varname> file that defines which Go libraries are needed and
should be included in <varname>GOPATH</varname> for
<varname>buildPhase</varname>.
</para>
</para>
<para>The <varname>goDeps</varname> attribute can be imported from a separate
<varname>nix</varname> file that defines which Go libraries are needed and should
be included in <varname>GOPATH</varname> for <varname>buildPhase</varname>.
</para>
<example xml:id='ex-goDeps'><title>deps.nix</title>
<example xml:id='ex-goDeps'>
<title>deps.nix</title>
<programlisting>
[ <co xml:id='ex-goDeps-1' />
{
@ -100,67 +101,60 @@ the following arguments are of special significance to the function:
}
]
</programlisting>
</example>
</example>
<para>
<calloutlist>
<callout arearefs='ex-goDeps-1'>
<para>
<calloutlist>
<callout arearefs='ex-goDeps-1'>
<para>
<varname>goDeps</varname> is a list of Go dependencies.
<varname>goDeps</varname> is a list of Go dependencies.
</para>
</callout>
<callout arearefs='ex-goDeps-2'>
</callout>
<callout arearefs='ex-goDeps-2'>
<para>
<varname>goPackagePath</varname> specifies Go package import path.
<varname>goPackagePath</varname> specifies Go package import path.
</para>
</callout>
<callout arearefs='ex-goDeps-3'>
</callout>
<callout arearefs='ex-goDeps-3'>
<para>
<varname>fetch type</varname> that needs to be used to get package source. If <varname>git</varname>
is used there should be <varname>url</varname>, <varname>rev</varname> and <varname>sha256</varname>
defined next to it.
<varname>fetch type</varname> that needs to be used to get package source.
If <varname>git</varname> is used there should be <varname>url</varname>,
<varname>rev</varname> and <varname>sha256</varname> defined next to it.
</para>
</callout>
</callout>
</calloutlist>
</para>
</calloutlist>
<para>
To extract dependency information from a Go package in automated way use
<link xlink:href="https://github.com/kamilchm/go2nix">go2nix</link>. It can
produce complete derivation and <varname>goDeps</varname> file for Go
programs.
</para>
</para>
<para>To extract dependency information from a Go package in automated way use <link xlink:href="https://github.com/kamilchm/go2nix">go2nix</link>.
It can produce complete derivation and <varname>goDeps</varname> file for Go programs.</para>
<para>
<varname>buildGoPackage</varname> produces <xref linkend='chap-multiple-output' xrefstyle="select: title" />
where <varname>bin</varname> includes program binaries. You can test build a Go binary as follows:
<screen>
<para>
<varname>buildGoPackage</varname> produces
<xref linkend='chap-multiple-output' xrefstyle="select: title" /> where
<varname>bin</varname> includes program binaries. You can test build a Go
binary as follows:
<screen>
$ nix-build -A deis.bin
</screen>
or build all outputs with:
<screen>
<screen>
$ nix-build -A deis.all
</screen>
<varname>bin</varname> output will be installed by default with
<varname>nix-env -i</varname> or <varname>systemPackages</varname>.
</para>
<varname>bin</varname> output will be installed by default with <varname>nix-env -i</varname>
or <varname>systemPackages</varname>.
</para>
<para>
You may use Go packages installed into the active Nix profiles by adding
the following to your ~/.bashrc:
<para>
You may use Go packages installed into the active Nix profiles by adding the
following to your ~/.bashrc:
<screen>
for p in $NIX_PROFILES; do
GOPATH="$p/share/go:$GOPATH"
done
</screen>
</para>
</para>
</section>

59
doc/languages-frameworks/index.xml
View File

@ -1,36 +1,31 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xi="http://www.w3.org/2001/XInclude"
xml:id="chap-language-support">
<title>Support for specific programming languages and frameworks</title>
<para>The <link linkend="chap-stdenv">standard build
environment</link> makes it easy to build typical Autotools-based
packages with very little code. Any other kind of package can be
accomodated by overriding the appropriate phases of
<literal>stdenv</literal>. However, there are specialised functions
in Nixpkgs to easily build packages for other programming languages,
such as Perl or Haskell. These are described in this chapter.</para>
<xi:include href="beam.xml" />
<xi:include href="bower.xml" />
<xi:include href="coq.xml" />
<xi:include href="go.xml" />
<xi:include href="haskell.section.xml" />
<xi:include href="idris.section.xml" />
<xi:include href="java.xml" />
<xi:include href="lua.xml" />
<xi:include href="node.section.xml" />
<xi:include href="perl.xml" />
<xi:include href="python.section.xml" />
<xi:include href="qt.xml" />
<xi:include href="r.section.xml" />
<xi:include href="ruby.xml" />
<xi:include href="rust.section.xml" />
<xi:include href="texlive.xml" />
<xi:include href="vim.section.xml" />
<xi:include href="emscripten.section.xml" />
<title>Support for specific programming languages and frameworks</title>
<para>
The <link linkend="chap-stdenv">standard build environment</link> makes it
easy to build typical Autotools-based packages with very little code. Any
other kind of package can be accomodated by overriding the appropriate phases
of <literal>stdenv</literal>. However, there are specialised functions in
Nixpkgs to easily build packages for other programming languages, such as
Perl or Haskell. These are described in this chapter.
</para>
<xi:include href="beam.xml" />
<xi:include href="bower.xml" />
<xi:include href="coq.xml" />
<xi:include href="go.xml" />
<xi:include href="haskell.section.xml" />
<xi:include href="idris.section.xml" />
<xi:include href="java.xml" />
<xi:include href="lua.xml" />
<xi:include href="node.section.xml" />
<xi:include href="perl.xml" />
<xi:include href="python.section.xml" />
<xi:include href="qt.xml" />
<xi:include href="r.section.xml" />
<xi:include href="ruby.xml" />
<xi:include href="rust.section.xml" />
<xi:include href="texlive.xml" />
<xi:include href="vim.section.xml" />
<xi:include href="emscripten.section.xml" />
</chapter>

76
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@ -1,11 +1,10 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-java">
<title>Java</title>
<title>Java</title>
<para>Ant-based Java packages are typically built from source as follows:
<para>
Ant-based Java packages are typically built from source as follows:
<programlisting>
stdenv.mkDerivation {
name = "...";
@ -16,33 +15,33 @@ stdenv.mkDerivation {
buildPhase = "ant";
}
</programlisting>
Note that <varname>jdk</varname> is an alias for the OpenJDK.
</para>
Note that <varname>jdk</varname> is an alias for the OpenJDK.</para>
<para>JAR files that are intended to be used by other packages should
be installed in <filename>$out/share/java</filename>. The OpenJDK has
a stdenv setup hook that adds any JARs in the
<filename>share/java</filename> directories of the build inputs to the
<envar>CLASSPATH</envar> environment variable. For instance, if the
package <literal>libfoo</literal> installs a JAR named
<filename>foo.jar</filename> in its <filename>share/java</filename>
directory, and another package declares the attribute
<para>
JAR files that are intended to be used by other packages should be installed
in <filename>$out/share/java</filename>. The OpenJDK has a stdenv setup hook
that adds any JARs in the <filename>share/java</filename> directories of the
build inputs to the <envar>CLASSPATH</envar> environment variable. For
instance, if the package <literal>libfoo</literal> installs a JAR named
<filename>foo.jar</filename> in its <filename>share/java</filename>
directory, and another package declares the attribute
<programlisting>
buildInputs = [ jdk libfoo ];
</programlisting>
then <envar>CLASSPATH</envar> will be set to
<filename>/nix/store/...-libfoo/share/java/foo.jar</filename>.
</para>
then <envar>CLASSPATH</envar> will be set to
<filename>/nix/store/...-libfoo/share/java/foo.jar</filename>.</para>
<para>Private JARs
should be installed in a location like
<filename>$out/share/<replaceable>package-name</replaceable></filename>.</para>
<para>If your Java package provides a program, you need to generate a
wrapper script to run it using the OpenJRE. You can use
<literal>makeWrapper</literal> for this:
<para>
Private JARs should be installed in a location like
<filename>$out/share/<replaceable>package-name</replaceable></filename>.
</para>
<para>
If your Java package provides a program, you need to generate a wrapper
script to run it using the OpenJRE. You can use
<literal>makeWrapper</literal> for this:
<programlisting>
buildInputs = [ makeWrapper ];
@ -53,23 +52,20 @@ installPhase =
--add-flags "-cp $out/share/java/foo.jar org.foo.Main"
'';
</programlisting>
Note the use of <literal>jre</literal>, which is the part of the OpenJDK
package that contains the Java Runtime Environment. By using
<literal>${jre}/bin/java</literal> instead of
<literal>${jdk}/bin/java</literal>, you prevent your package from depending
on the JDK at runtime.
</para>
Note the use of <literal>jre</literal>, which is the part of the
OpenJDK package that contains the Java Runtime Environment. By using
<literal>${jre}/bin/java</literal> instead of
<literal>${jdk}/bin/java</literal>, you prevent your package from
depending on the JDK at runtime.</para>
<para>It is possible to use a different Java compiler than
<command>javac</command> from the OpenJDK. For instance, to use the
GNU Java Compiler:
<para>
It is possible to use a different Java compiler than <command>javac</command>
from the OpenJDK. For instance, to use the GNU Java Compiler:
<programlisting>
buildInputs = [ gcj ant ];
</programlisting>
Here, Ant will automatically use <command>gij</command> (the GNU Java
Runtime) instead of the OpenJRE.</para>
Here, Ant will automatically use <command>gij</command> (the GNU Java
Runtime) instead of the OpenJRE.
</para>
</section>

43
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@ -1,24 +1,22 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-lua">
<title>Lua</title>
<title>Lua</title>
<para>
Lua packages are built by the <varname>buildLuaPackage</varname> function. This function is
implemented
in <link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/lua-modules/generic/default.nix">
<para>
Lua packages are built by the <varname>buildLuaPackage</varname> function.
This function is implemented in
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/lua-modules/generic/default.nix">
<filename>pkgs/development/lua-modules/generic/default.nix</filename></link>
and works similarly to <varname>buildPerlPackage</varname>. (See
<xref linkend="sec-language-perl"/> for details.)
</para>
</para>
<para>
Lua packages are defined
in <link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/lua-packages.nix"><filename>pkgs/top-level/lua-packages.nix</filename></link>.
<para>
Lua packages are defined in
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/lua-packages.nix"><filename>pkgs/top-level/lua-packages.nix</filename></link>.
Most of them are simple. For example:
<programlisting>
<programlisting>
fileSystem = buildLuaPackage {
name = "filesystem-1.6.2";
src = fetchurl {
@ -32,20 +30,19 @@ fileSystem = buildLuaPackage {
};
};
</programlisting>
</para>
</para>
<para>
<para>
Though, more complicated package should be placed in a seperate file in
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/lua-modules"><filename>pkgs/development/lua-modules</filename></link>.
</para>
<para>
Lua packages accept additional parameter <varname>disabled</varname>, which defines
the condition of disabling package from luaPackages. For example, if package has
<varname>disabled</varname> assigned to <literal>lua.luaversion != "5.1"</literal>,
it will not be included in any luaPackages except lua51Packages, making it
only be built for lua 5.1.
</para>
</para>
<para>
Lua packages accept additional parameter <varname>disabled</varname>, which
defines the condition of disabling package from luaPackages. For example, if
package has <varname>disabled</varname> assigned to <literal>lua.luaversion
!= "5.1"</literal>, it will not be included in any luaPackages except
lua51Packages, making it only be built for lua 5.1.
</para>
</section>

219
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@ -1,24 +1,27 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-perl">
<title>Perl</title>
<title>Perl</title>
<para>
Nixpkgs provides a function <varname>buildPerlPackage</varname>, a generic
package builder function for any Perl package that has a standard
<varname>Makefile.PL</varname>. It’s implemented in
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/perl-modules/generic"><filename>pkgs/development/perl-modules/generic</filename></link>.
</para>
<para>Nixpkgs provides a function <varname>buildPerlPackage</varname>,
a generic package builder function for any Perl package that has a
standard <varname>Makefile.PL</varname>. It’s implemented in <link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/perl-modules/generic"><filename>pkgs/development/perl-modules/generic</filename></link>.</para>
<para>Perl packages from CPAN are defined in <link
<para>
Perl packages from CPAN are defined in
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/perl-packages.nix"><filename>pkgs/top-level/perl-packages.nix</filename></link>,
rather than <filename>pkgs/all-packages.nix</filename>. Most Perl
packages are so straight-forward to build that they are defined here
directly, rather than having a separate function for each package
called from <filename>perl-packages.nix</filename>. However, more
complicated packages should be put in a separate file, typically in
<filename>pkgs/development/perl-modules</filename>. Here is an
example of the former:
rather than <filename>pkgs/all-packages.nix</filename>. Most Perl packages
are so straight-forward to build that they are defined here directly, rather
than having a separate function for each package called from
<filename>perl-packages.nix</filename>. However, more complicated packages
should be put in a separate file, typically in
<filename>pkgs/development/perl-modules</filename>. Here is an example of the
former:
<programlisting>
ClassC3 = buildPerlPackage rec {
name = "Class-C3-0.21";
@ -28,74 +31,72 @@ ClassC3 = buildPerlPackage rec {
};
};
</programlisting>
Note the use of <literal>mirror://cpan/</literal>, and the
<literal>${name}</literal> in the URL definition to ensure that the
name attribute is consistent with the source that we’re actually
downloading. Perl packages are made available in
<filename>all-packages.nix</filename> through the variable
<varname>perlPackages</varname>. For instance, if you have a package
that needs <varname>ClassC3</varname>, you would typically write
Note the use of <literal>mirror://cpan/</literal>, and the
<literal>${name}</literal> in the URL definition to ensure that the name
attribute is consistent with the source that we’re actually downloading.
Perl packages are made available in <filename>all-packages.nix</filename>
through the variable <varname>perlPackages</varname>. For instance, if you
have a package that needs <varname>ClassC3</varname>, you would typically
write
<programlisting>
foo = import ../path/to/foo.nix {
inherit stdenv fetchurl ...;
inherit (perlPackages) ClassC3;
};
</programlisting>
in <filename>all-packages.nix</filename>. You can test building a
Perl package as follows:
in <filename>all-packages.nix</filename>. You can test building a Perl
package as follows:
<screen>
$ nix-build -A perlPackages.ClassC3
</screen>
<varname>buildPerlPackage</varname> adds <literal>perl-</literal> to
the start of the name attribute, so the package above is actually
called <literal>perl-Class-C3-0.21</literal>. So to install it, you
can say:
<varname>buildPerlPackage</varname> adds <literal>perl-</literal> to the
start of the name attribute, so the package above is actually called
<literal>perl-Class-C3-0.21</literal>. So to install it, you can say:
<screen>
$ nix-env -i perl-Class-C3
</screen>
(Of course you can also install using the attribute name: <literal>nix-env -i
-A perlPackages.ClassC3</literal>.)
</para>
(Of course you can also install using the attribute name:
<literal>nix-env -i -A perlPackages.ClassC3</literal>.)</para>
<para>So what does <varname>buildPerlPackage</varname> do? It does
the following:
<orderedlist>
<listitem><para>In the configure phase, it calls <literal>perl
Makefile.PL</literal> to generate a Makefile. You can set the
variable <varname>makeMakerFlags</varname> to pass flags to
<filename>Makefile.PL</filename></para></listitem>
<listitem><para>It adds the contents of the <envar>PERL5LIB</envar>
environment variable to <literal>#! .../bin/perl</literal> line of
Perl scripts as <literal>-I<replaceable>dir</replaceable></literal>
flags. This ensures that a script can find its
dependencies.</para></listitem>
<listitem><para>In the fixup phase, it writes the propagated build
inputs (<varname>propagatedBuildInputs</varname>) to the file
<filename>$out/nix-support/propagated-user-env-packages</filename>.
<command>nix-env</command> recursively installs all packages listed
in this file when you install a package that has it. This ensures
that a Perl package can find its dependencies.</para></listitem>
</orderedlist>
</para>
<para><varname>buildPerlPackage</varname> is built on top of
<varname>stdenv</varname>, so everything can be customised in the
usual way. For instance, the <literal>BerkeleyDB</literal> module has
a <varname>preConfigure</varname> hook to generate a configuration
file used by <filename>Makefile.PL</filename>:
<para>
So what does <varname>buildPerlPackage</varname> do? It does the following:
<orderedlist>
<listitem>
<para>
In the configure phase, it calls <literal>perl Makefile.PL</literal> to
generate a Makefile. You can set the variable
<varname>makeMakerFlags</varname> to pass flags to
<filename>Makefile.PL</filename>
</para>
</listitem>
<listitem>
<para>
It adds the contents of the <envar>PERL5LIB</envar> environment variable
to <literal>#! .../bin/perl</literal> line of Perl scripts as
<literal>-I<replaceable>dir</replaceable></literal> flags. This ensures
that a script can find its dependencies.
</para>
</listitem>
<listitem>
<para>
In the fixup phase, it writes the propagated build inputs
(<varname>propagatedBuildInputs</varname>) to the file
<filename>$out/nix-support/propagated-user-env-packages</filename>.
<command>nix-env</command> recursively installs all packages listed in
this file when you install a package that has it. This ensures that a Perl
package can find its dependencies.
</para>
</listitem>
</orderedlist>
</para>
<para>
<varname>buildPerlPackage</varname> is built on top of
<varname>stdenv</varname>, so everything can be customised in the usual way.
For instance, the <literal>BerkeleyDB</literal> module has a
<varname>preConfigure</varname> hook to generate a configuration file used by
<filename>Makefile.PL</filename>:
<programlisting>
{ buildPerlPackage, fetchurl, db }:
@ -113,18 +114,15 @@ buildPerlPackage rec {
'';
}
</programlisting>
</para>
</para>
<para>Dependencies on other Perl packages can be specified in the
<varname>buildInputs</varname> and
<varname>propagatedBuildInputs</varname> attributes. If something is
exclusively a build-time dependency, use
<varname>buildInputs</varname>; if it’s (also) a runtime dependency,
use <varname>propagatedBuildInputs</varname>. For instance, this
builds a Perl module that has runtime dependencies on a bunch of other
modules:
<para>
Dependencies on other Perl packages can be specified in the
<varname>buildInputs</varname> and <varname>propagatedBuildInputs</varname>
attributes. If something is exclusively a build-time dependency, use
<varname>buildInputs</varname>; if it’s (also) a runtime dependency, use
<varname>propagatedBuildInputs</varname>. For instance, this builds a Perl
module that has runtime dependencies on a bunch of other modules:
<programlisting>
ClassC3Componentised = buildPerlPackage rec {
name = "Class-C3-Componentised-1.0004";
@ -137,24 +135,26 @@ ClassC3Componentised = buildPerlPackage rec {
];
};
</programlisting>
</para>
</para>
<section xml:id="ssec-generation-from-CPAN">
<title>Generation from CPAN</title>
<section xml:id="ssec-generation-from-CPAN"><title>Generation from CPAN</title>
<para>Nix expressions for Perl packages can be generated (almost)
automatically from CPAN. This is done by the program
<command>nix-generate-from-cpan</command>, which can be installed
as follows:</para>
<para>
Nix expressions for Perl packages can be generated (almost) automatically
from CPAN. This is done by the program
<command>nix-generate-from-cpan</command>, which can be installed as
follows:
</para>
<screen>
$ nix-env -i nix-generate-from-cpan
</screen>
<para>This program takes a Perl module name, looks it up on CPAN,
fetches and unpacks the corresponding package, and prints a Nix
expression on standard output. For example:
<para>
This program takes a Perl module name, looks it up on CPAN, fetches and
unpacks the corresponding package, and prints a Nix expression on standard
output. For example:
<screen>
$ nix-generate-from-cpan XML::Simple
XMLSimple = buildPerlPackage rec {
@ -170,26 +170,23 @@ $ nix-generate-from-cpan XML::Simple
};
};
</screen>
The output can be pasted into
<filename>pkgs/top-level/perl-packages.nix</filename> or wherever else you
need it.
</para>
</section>
The output can be pasted into
<filename>pkgs/top-level/perl-packages.nix</filename> or wherever else
you need it.</para>
<section xml:id="ssec-perl-cross-compilation">
<title>Cross-compiling modules</title>
<para>
Nixpkgs has experimental support for cross-compiling Perl modules. In many
cases, it will just work out of the box, even for modules with native
extensions. Sometimes, however, the Makefile.PL for a module may
(indirectly) import a native module. In that case, you will need to make a
stub for that module that will satisfy the Makefile.PL and install it into
<filename>lib/perl5/site_perl/cross_perl/${perl.version}</filename>. See the
<varname>postInstall</varname> for <varname>DBI</varname> for an example.
</para>
</section>
</section>
<section xml:id="ssec-perl-cross-compilation"><title>Cross-compiling modules</title>
<para>Nixpkgs has experimental support for cross-compiling Perl
modules. In many cases, it will just work out of the box, even for
modules with native extensions. Sometimes, however, the Makefile.PL
for a module may (indirectly) import a native module. In that case,
you will need to make a stub for that module that will satisfy the
Makefile.PL and install it into
<filename>lib/perl5/site_perl/cross_perl/${perl.version}</filename>.
See the <varname>postInstall</varname> for <varname>DBI</varname> for
an example.</para>
</section>
</section>

112
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@ -1,58 +1,74 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-qt">
<title>Qt</title>
<title>Qt</title>
<para>
Qt is a comprehensive desktop and mobile application development toolkit for
C++. Legacy support is available for Qt 3 and Qt 4, but all current
development uses Qt 5. The Qt 5 packages in Nixpkgs are updated frequently to
take advantage of new features, but older versions are typically retained
until their support window ends. The most important consideration in
packaging Qt-based software is ensuring that each package and all its
dependencies use the same version of Qt 5; this consideration motivates most
of the tools described below.
</para>
<para>
Qt is a comprehensive desktop and mobile application development toolkit for C++.
Legacy support is available for Qt 3 and Qt 4, but all current development uses Qt 5.
The Qt 5 packages in Nixpkgs are updated frequently to take advantage of new features,
but older versions are typically retained until their support window ends.
The most important consideration in packaging Qt-based software is ensuring that each package and all its dependencies use the same version of Qt 5;
this consideration motivates most of the tools described below.
</para>
<section xml:id="ssec-qt-libraries">
<title>Packaging Libraries for Nixpkgs</title>
<section xml:id="ssec-qt-libraries"><title>Packaging Libraries for Nixpkgs</title>
<para>
Whenever possible, libraries that use Qt 5 should be built with each
available version. Packages providing libraries should be added to the
top-level function <varname>mkLibsForQt5</varname>, which is used to build a
set of libraries for every Qt 5 version. A special
<varname>callPackage</varname> function is used in this scope to ensure that
the entire dependency tree uses the same Qt 5 version. Import dependencies
unqualified, i.e., <literal>qtbase</literal> not
<literal>qt5.qtbase</literal>. <emphasis>Do not</emphasis> import a package
set such as <literal>qt5</literal> or <literal>libsForQt5</literal>.
</para>
<para>
Whenever possible, libraries that use Qt 5 should be built with each available version.
Packages providing libraries should be added to the top-level function <varname>mkLibsForQt5</varname>,
which is used to build a set of libraries for every Qt 5 version.
A special <varname>callPackage</varname> function is used in this scope to ensure that the entire dependency tree uses the same Qt 5 version.
Import dependencies unqualified, i.e., <literal>qtbase</literal> not <literal>qt5.qtbase</literal>.
<emphasis>Do not</emphasis> import a package set such as <literal>qt5</literal> or <literal>libsForQt5</literal>.
</para>
<para>
If a library does not support a particular version of Qt 5, it is best to
mark it as broken by setting its <literal>meta.broken</literal> attribute. A
package may be marked broken for certain versions by testing the
<literal>qtbase.version</literal> attribute, which will always give the
current Qt 5 version.
</para>
</section>
<para>
If a library does not support a particular version of Qt 5, it is best to mark it as broken by setting its <literal>meta.broken</literal> attribute.
A package may be marked broken for certain versions by testing the <literal>qtbase.version</literal> attribute, which will always give the current Qt 5 version.
</para>
<section xml:id="ssec-qt-applications">
<title>Packaging Applications for Nixpkgs</title>
<para>
Call your application expression using
<literal>libsForQt5.callPackage</literal> instead of
<literal>callPackage</literal>. Import dependencies unqualified, i.e.,
<literal>qtbase</literal> not <literal>qt5.qtbase</literal>. <emphasis>Do
not</emphasis> import a package set such as <literal>qt5</literal> or
<literal>libsForQt5</literal>.
</para>
<para>
Qt 5 maintains strict backward compatibility, so it is generally best to
build an application package against the latest version using the
<varname>libsForQt5</varname> library set. In case a package does not build
with the latest Qt version, it is possible to pick a set pinned to a
particular version, e.g. <varname>libsForQt55</varname> for Qt 5.5, if that
is the latest version the package supports. If a package must be pinned to
an older Qt version, be sure to file a bug upstream; because Qt is strictly
backwards-compatible, any incompatibility is by definition a bug in the
application.
</para>
<para>
When testing applications in Nixpkgs, it is a common practice to build the
package with <literal>nix-build</literal> and run it using the created
symbolic link. This will not work with Qt applications, however, because
they have many hard runtime requirements that can only be guaranteed if the
package is actually installed. To test a Qt application, install it with
<literal>nix-env</literal> or run it inside <literal>nix-shell</literal>.
</para>
</section>
</section>
<section xml:id="ssec-qt-applications"><title>Packaging Applications for Nixpkgs</title>
<para>
Call your application expression using <literal>libsForQt5.callPackage</literal> instead of <literal>callPackage</literal>.
Import dependencies unqualified, i.e., <literal>qtbase</literal> not <literal>qt5.qtbase</literal>.
<emphasis>Do not</emphasis> import a package set such as <literal>qt5</literal> or <literal>libsForQt5</literal>.
</para>
<para>
Qt 5 maintains strict backward compatibility, so it is generally best to build an application package against the latest version using the <varname>libsForQt5</varname> library set.
In case a package does not build with the latest Qt version, it is possible to pick a set pinned to a particular version, e.g. <varname>libsForQt55</varname> for Qt 5.5, if that is the latest version the package supports.
If a package must be pinned to an older Qt version, be sure to file a bug upstream;
because Qt is strictly backwards-compatible, any incompatibility is by definition a bug in the application.
</para>
<para>
When testing applications in Nixpkgs, it is a common practice to build the package with <literal>nix-build</literal> and run it using the created symbolic link.
This will not work with Qt applications, however, because they have many hard runtime requirements that can only be guaranteed if the package is actually installed.
To test a Qt application, install it with <literal>nix-env</literal> or run it inside <literal>nix-shell</literal>.
</para>
</section>
</section>

90
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@ -1,17 +1,19 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-ruby">
<title>Ruby</title>
<title>Ruby</title>
<para>
There currently is support to bundle applications that are packaged as Ruby
gems. The utility "bundix" allows you to write a
<filename>Gemfile</filename>, let bundler create a
<filename>Gemfile.lock</filename>, and then convert this into a nix
expression that contains all Gem dependencies automatically.
</para>
<para>There currently is support to bundle applications that are packaged as
Ruby gems. The utility "bundix" allows you to write a
<filename>Gemfile</filename>, let bundler create a
<filename>Gemfile.lock</filename>, and then convert this into a nix
expression that contains all Gem dependencies automatically.
</para>
<para>For example, to package sensu, we did:</para>
<para>
For example, to package sensu, we did:
</para>
<screen>
<![CDATA[$ cd pkgs/servers/monitoring
@ -42,17 +44,18 @@ bundlerEnv rec {
}]]>
</screen>
<para>Please check in the <filename>Gemfile</filename>,
<filename>Gemfile.lock</filename> and the
<filename>gemset.nix</filename> so future updates can be run easily.
</para>
<para>
Please check in the <filename>Gemfile</filename>,
<filename>Gemfile.lock</filename> and the <filename>gemset.nix</filename> so
future updates can be run easily.
</para>
<para>For tools written in Ruby - i.e. where the desire is to install
a package and then execute e.g. <command>rake</command> at the command
line, there is an alternative builder called <literal>bundlerApp</literal>.
Set up the <filename>gemset.nix</filename> the same way, and then, for
example:
</para>
<para>
For tools written in Ruby - i.e. where the desire is to install a package and
then execute e.g. <command>rake</command> at the command line, there is an
alternative builder called <literal>bundlerApp</literal>. Set up the
<filename>gemset.nix</filename> the same way, and then, for example:
</para>
<screen>
<![CDATA[{ lib, bundlerApp }:
@ -72,31 +75,31 @@ bundlerApp {
}]]>
</screen>
<para>The chief advantage of <literal>bundlerApp</literal> over
<literal>bundlerEnv</literal> is the executables introduced in the
environment are precisely those selected in the <literal>exes</literal>
list, as opposed to <literal>bundlerEnv</literal> which adds all the
executables made available by gems in the gemset, which can mean e.g.
<command>rspec</command> or <command>rake</command> in unpredictable
versions available from various packages.
</para>
<para>
The chief advantage of <literal>bundlerApp</literal> over
<literal>bundlerEnv</literal> is the executables introduced in the
environment are precisely those selected in the <literal>exes</literal> list,
as opposed to <literal>bundlerEnv</literal> which adds all the executables
made available by gems in the gemset, which can mean e.g.
<command>rspec</command> or <command>rake</command> in unpredictable versions
available from various packages.
</para>
<para>Resulting derivations for both builders also have two helpful
attributes, <literal>env</literal> and <literal>wrappedRuby</literal>.
The first one allows one to quickly drop into
<command>nix-shell</command> with the specified environment present.
E.g. <command>nix-shell -A sensu.env</command> would give you an
environment with Ruby preset so it has all the libraries necessary
for <literal>sensu</literal> in its paths. The second one can be
used to make derivations from custom Ruby scripts which have
<filename>Gemfile</filename>s with their dependencies specified. It is
a derivation with <command>ruby</command> wrapped so it can find all
the needed dependencies. For example, to make a derivation
<literal>my-script</literal> for a <filename>my-script.rb</filename>
(which should be placed in <filename>bin</filename>) you should run
<command>bundix</command> as specified above and then use
<literal>bundlerEnv</literal> like this:
</para>
<para>
Resulting derivations for both builders also have two helpful attributes,
<literal>env</literal> and <literal>wrappedRuby</literal>. The first one
allows one to quickly drop into <command>nix-shell</command> with the
specified environment present. E.g. <command>nix-shell -A sensu.env</command>
would give you an environment with Ruby preset so it has all the libraries
necessary for <literal>sensu</literal> in its paths. The second one can be
used to make derivations from custom Ruby scripts which have
<filename>Gemfile</filename>s with their dependencies specified. It is a
derivation with <command>ruby</command> wrapped so it can find all the needed
dependencies. For example, to make a derivation <literal>my-script</literal>
for a <filename>my-script.rb</filename> (which should be placed in
<filename>bin</filename>) you should run <command>bundix</command> as
specified above and then use <literal>bundlerEnv</literal> like this:
</para>
<programlisting>
<![CDATA[let env = bundlerEnv {
@ -118,5 +121,4 @@ in stdenv.mkDerivation {
'';
}]]>
</programlisting>
</section>

108
doc/languages-frameworks/texlive.xml
View File

@ -1,27 +1,42 @@
<section xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="sec-language-texlive">
<title>TeX Live</title>
<title>TeX Live</title>
<para>
Since release 15.09 there is a new TeX Live packaging that lives entirely
under attribute <varname>texlive</varname>.
</para>
<section>
<title>User's guide</title>
<para>Since release 15.09 there is a new TeX Live packaging that lives entirely under attribute <varname>texlive</varname>.</para>
<section><title>User's guide</title>
<itemizedlist>
<listitem><para>
For basic usage just pull <varname>texlive.combined.scheme-basic</varname> for an environment with basic LaTeX support.</para></listitem>
<listitem><para>
It typically won't work to use separately installed packages together.
Instead, you can build a custom set of packages like this:
<programlisting>
<listitem>
<para>
For basic usage just pull <varname>texlive.combined.scheme-basic</varname>
for an environment with basic LaTeX support.
</para>
</listitem>
<listitem>
<para>
It typically won't work to use separately installed packages together.
Instead, you can build a custom set of packages like this:
<programlisting>
texlive.combine {
inherit (texlive) scheme-small collection-langkorean algorithms cm-super;
}
</programlisting>
There are all the schemes, collections and a few thousand packages, as defined upstream (perhaps with tiny differences).
</para></listitem>
<listitem><para>
By default you only get executables and files needed during runtime, and a little documentation for the core packages. To change that, you need to add <varname>pkgFilter</varname> function to <varname>combine</varname>.
<programlisting>
There are all the schemes, collections and a few thousand packages, as
defined upstream (perhaps with tiny differences).
</para>
</listitem>
<listitem>
<para>
By default you only get executables and files needed during runtime, and a
little documentation for the core packages. To change that, you need to
add <varname>pkgFilter</varname> function to <varname>combine</varname>.
<programlisting>
texlive.combine {
# inherit (texlive) whatever-you-want;
pkgFilter = pkg:
@ -30,34 +45,55 @@ texlive.combine {
# there are also other attributes: version, name
}
</programlisting>
</para></listitem>
<listitem><para>
You can list packages e.g. by <command>nix-repl</command>.
<programlisting>
</para>
</listitem>
<listitem>
<para>
You can list packages e.g. by <command>nix-repl</command>.
<programlisting>
$ nix-repl
nix-repl> :l &lt;nixpkgs>
nix-repl> texlive.collection-&lt;TAB>
</programlisting>
</para></listitem>
<listitem><para>
Note that the wrapper assumes that the result has a chance to be useful. For example, the core executables should be present, as well as some core data files. The supported way of ensuring this is by including some scheme, for example <varname>scheme-basic</varname>, into the combination.
</para></listitem>
</para>
</listitem>
<listitem>
<para>
Note that the wrapper assumes that the result has a chance to be useful.
For example, the core executables should be present, as well as some core
data files. The supported way of ensuring this is by including some
scheme, for example <varname>scheme-basic</varname>, into the combination.
</para>
</listitem>
</itemizedlist>
</section>
</section>
<section>
<title>Known problems</title>
<section><title>Known problems</title>
<itemizedlist>
<listitem><para>
Some tools are still missing, e.g. luajittex;</para></listitem>
<listitem><para>
some apps aren't packaged/tested yet (asymptote, biber, etc.);</para></listitem>
<listitem><para>
feature/bug: when a package is rejected by <varname>pkgFilter</varname>, its dependencies are still propagated;</para></listitem>
<listitem><para>
in case of any bugs or feature requests, file a github issue or better a pull request and /cc @vcunat.</para></listitem>
<listitem>
<para>
Some tools are still missing, e.g. luajittex;
</para>
</listitem>
<listitem>
<para>
some apps aren't packaged/tested yet (asymptote, biber, etc.);
</para>
</listitem>
<listitem>
<para>
feature/bug: when a package is rejected by <varname>pkgFilter</varname>,
its dependencies are still propagated;
</para>
</listitem>
<listitem>
<para>
in case of any bugs or feature requests, file a github issue or better a
pull request and /cc @vcunat.
</para>
</listitem>
</itemizedlist>
</section>
</section>
</section>

47
doc/manual.xml
View File

@ -1,29 +1,24 @@
<book xmlns="http://docbook.org/ns/docbook"
xmlns:xi="http://www.w3.org/2001/XInclude">
<info>
<title>Nixpkgs Contributors Guide</title>
<subtitle>Version <xi:include href=".version" parse="text" /></subtitle>
</info>
<xi:include href="introduction.chapter.xml" />
<xi:include href="quick-start.xml" />
<xi:include href="stdenv.xml" />
<xi:include href="multiple-output.xml" />
<xi:include href="cross-compilation.xml" />
<xi:include href="configuration.xml" />
<xi:include href="functions.xml" />
<xi:include href="meta.xml" />
<xi:include href="languages-frameworks/index.xml" />
<xi:include href="platform-notes.xml" />
<xi:include href="package-notes.xml" />
<xi:include href="overlays.xml" />
<xi:include href="coding-conventions.xml" />
<xi:include href="submitting-changes.xml" />
<xi:include href="reviewing-contributions.xml" />
<xi:include href="contributing.xml" />
<info>
<title>Nixpkgs Contributors Guide</title>
<subtitle>Version <xi:include href=".version" parse="text" />
</subtitle>
</info>
<xi:include href="introduction.chapter.xml" />
<xi:include href="quick-start.xml" />
<xi:include href="stdenv.xml" />
<xi:include href="multiple-output.xml" />
<xi:include href="cross-compilation.xml" />
<xi:include href="configuration.xml" />
<xi:include href="functions.xml" />
<xi:include href="meta.xml" />
<xi:include href="languages-frameworks/index.xml" />
<xi:include href="platform-notes.xml" />
<xi:include href="package-notes.xml" />
<xi:include href="overlays.xml" />
<xi:include href="coding-conventions.xml" />
<xi:include href="submitting-changes.xml" />
<xi:include href="reviewing-contributions.xml" />
<xi:include href="contributing.xml" />
</book>

540
doc/meta.xml
View File

@ -1,14 +1,12 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-meta">
<title>Meta-attributes</title>
<para>Nix packages can declare <emphasis>meta-attributes</emphasis>
that contain information about a package such as a description, its
homepage, its license, and so on. For instance, the GNU Hello package
has a <varname>meta</varname> declaration like this:
<title>Meta-attributes</title>
<para>
Nix packages can declare <emphasis>meta-attributes</emphasis> that contain
information about a package such as a description, its homepage, its license,
and so on. For instance, the GNU Hello package has a <varname>meta</varname>
declaration like this:
<programlisting>
meta = {
description = "A program that produces a familiar, friendly greeting";
@ -22,16 +20,15 @@ meta = {
platforms = stdenv.lib.platforms.all;
};
</programlisting>
</para>
<para>Meta-attributes are not passed to the builder of the package.
Thus, a change to a meta-attribute doesn’t trigger a recompilation of
the package. The value of a meta-attribute must be a string.</para>
<para>The meta-attributes of a package can be queried from the
command-line using <command>nix-env</command>:
</para>
<para>
Meta-attributes are not passed to the builder of the package. Thus, a change
to a meta-attribute doesn’t trigger a recompilation of the package. The
value of a meta-attribute must be a string.
</para>
<para>
The meta-attributes of a package can be queried from the command-line using
<command>nix-env</command>:
<screen>
$ nix-env -qa hello --json
{
@ -70,252 +67,299 @@ $ nix-env -qa hello --json
</screen>
<command>nix-env</command> knows about the
<varname>description</varname> field specifically:
<command>nix-env</command> knows about the <varname>description</varname>
field specifically:
<screen>
$ nix-env -qa hello --description
hello-2.3 A program that produces a familiar, friendly greeting
</screen>
</para>
<section xml:id="sec-standard-meta-attributes">
<title>Standard meta-attributes</title>
</para>
<para>
It is expected that each meta-attribute is one of the following:
</para>
<section xml:id="sec-standard-meta-attributes"><title>Standard
meta-attributes</title>
<para>It is expected that each meta-attribute is one of the following:</para>
<variablelist>
<varlistentry>
<term><varname>description</varname></term>
<listitem><para>A short (one-line) description of the package.
This is shown by <command>nix-env -q --description</command> and
also on the Nixpkgs release pages.</para>
<para>Don’t include a period at the end. Don’t include newline
characters. Capitalise the first character. For brevity, don’t
repeat the name of package — just describe what it does.</para>
<para>Wrong: <literal>"libpng is a library that allows you to decode PNG images."</literal></para>
<para>Right: <literal>"A library for decoding PNG images"</literal></para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>longDescription</varname></term>
<listitem><para>An arbitrarily long description of the
package.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>branch</varname></term>
<listitem><para>Release branch. Used to specify that a package is not
going to receive updates that are not in this branch; for example, Linux
kernel 3.0 is supposed to be updated to 3.0.X, not 3.1.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>homepage</varname></term>
<listitem><para>The package’s homepage. Example:
<literal>http://www.gnu.org/software/hello/manual/</literal></para></listitem>
</varlistentry>
<varlistentry>
<term><varname>downloadPage</varname></term>
<listitem><para>The page where a link to the current version can be found. Example:
<literal>http://ftp.gnu.org/gnu/hello/</literal></para></listitem>
</varlistentry>
<varlistentry>
<term><varname>license</varname></term>
<variablelist>
<varlistentry>
<term><varname>description</varname>
</term>
<listitem>
<para>
The license, or licenses, for the package. One from the attribute set
defined in <link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/lib/licenses.nix">
<filename>nixpkgs/lib/licenses.nix</filename></link>. At this moment
using both a list of licenses and a single license is valid. If the
license field is in the form of a list representation, then it means
that parts of the package are licensed differently. Each license
should preferably be referenced by their attribute. The non-list
attribute value can also be a space delimited string representation of
the contained attribute shortNames or spdxIds. The following are all valid
examples:
<itemizedlist>
<listitem><para>Single license referenced by attribute (preferred)
<literal>stdenv.lib.licenses.gpl3</literal>.
</para></listitem>
<listitem><para>Single license referenced by its attribute shortName (frowned upon)
<literal>"gpl3"</literal>.
</para></listitem>
<listitem><para>Single license referenced by its attribute spdxId (frowned upon)
<literal>"GPL-3.0"</literal>.
</para></listitem>
<listitem><para>Multiple licenses referenced by attribute (preferred)
<literal>with stdenv.lib.licenses; [ asl20 free ofl ]</literal>.
</para></listitem>
<listitem><para>Multiple licenses referenced as a space delimited string of attribute shortNames (frowned upon)
<literal>"asl20 free ofl"</literal>.
</para></listitem>
</itemizedlist>
For details, see <xref linkend='sec-meta-license'/>.
</para>
<para>
A short (one-line) description of the package. This is shown by
<command>nix-env -q --description</command> and also on the Nixpkgs
release pages.
</para>
<para>
Don’t include a period at the end. Don’t include newline characters.
Capitalise the first character. For brevity, don’t repeat the name of
package — just describe what it does.
</para>
<para>
Wrong: <literal>"libpng is a library that allows you to decode PNG
images."</literal>
</para>
<para>
Right: <literal>"A library for decoding PNG images"</literal>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>maintainers</varname></term>
<listitem><para>A list of names and e-mail addresses of the
maintainers of this Nix expression. If
you would like to be a maintainer of a package, you may want to add
yourself to <link
</varlistentry>
<varlistentry>
<term><varname>longDescription</varname>
</term>
<listitem>
<para>
An arbitrarily long description of the package.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>branch</varname>
</term>
<listitem>
<para>
Release branch. Used to specify that a package is not going to receive
updates that are not in this branch; for example, Linux kernel 3.0 is
supposed to be updated to 3.0.X, not 3.1.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>homepage</varname>
</term>
<listitem>
<para>
The package’s homepage. Example:
<literal>http://www.gnu.org/software/hello/manual/</literal>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>downloadPage</varname>
</term>
<listitem>
<para>
The page where a link to the current version can be found. Example:
<literal>http://ftp.gnu.org/gnu/hello/</literal>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>license</varname>
</term>
<listitem>
<para>
The license, or licenses, for the package. One from the attribute set
defined in
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/lib/licenses.nix">
<filename>nixpkgs/lib/licenses.nix</filename></link>. At this moment
using both a list of licenses and a single license is valid. If the
license field is in the form of a list representation, then it means that
parts of the package are licensed differently. Each license should
preferably be referenced by their attribute. The non-list attribute value
can also be a space delimited string representation of the contained
attribute shortNames or spdxIds. The following are all valid examples:
<itemizedlist>
<listitem>
<para>
Single license referenced by attribute (preferred)
<literal>stdenv.lib.licenses.gpl3</literal>.
</para>
</listitem>
<listitem>
<para>
Single license referenced by its attribute shortName (frowned upon)
<literal>"gpl3"</literal>.
</para>
</listitem>
<listitem>
<para>
Single license referenced by its attribute spdxId (frowned upon)
<literal>"GPL-3.0"</literal>.
</para>
</listitem>
<listitem>
<para>
Multiple licenses referenced by attribute (preferred) <literal>with
stdenv.lib.licenses; [ asl20 free ofl ]</literal>.
</para>
</listitem>
<listitem>
<para>
Multiple licenses referenced as a space delimited string of attribute
shortNames (frowned upon) <literal>"asl20 free ofl"</literal>.
</para>
</listitem>
</itemizedlist>
For details, see <xref linkend='sec-meta-license'/>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>maintainers</varname>
</term>
<listitem>
<para>
A list of names and e-mail addresses of the maintainers of this Nix
expression. If you would like to be a maintainer of a package, you may
want to add yourself to
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/maintainers/maintainer-list.nix"><filename>nixpkgs/maintainers/maintainer-list.nix</filename></link>
and write something like <literal>[ stdenv.lib.maintainers.alice
stdenv.lib.maintainers.bob ]</literal>.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>priority</varname></term>
<listitem><para>The <emphasis>priority</emphasis> of the package,
used by <command>nix-env</command> to resolve file name conflicts
between packages. See the Nix manual page for
<command>nix-env</command> for details. Example:
<literal>"10"</literal> (a low-priority
package).</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>platforms</varname></term>
<listitem><para>The list of Nix platform types on which the
package is supported. Hydra builds packages according to the
platform specified. If no platform is specified, the package does
not have prebuilt binaries. An example is:
and write something like <literal>[ stdenv.lib.maintainers.alice
stdenv.lib.maintainers.bob ]</literal>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>priority</varname>
</term>
<listitem>
<para>
The <emphasis>priority</emphasis> of the package, used by
<command>nix-env</command> to resolve file name conflicts between
packages. See the Nix manual page for <command>nix-env</command> for
details. Example: <literal>"10"</literal> (a low-priority package).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>platforms</varname>
</term>
<listitem>
<para>
The list of Nix platform types on which the package is supported. Hydra
builds packages according to the platform specified. If no platform is
specified, the package does not have prebuilt binaries. An example is:
<programlisting>
meta.platforms = stdenv.lib.platforms.linux;
</programlisting>
Attribute Set <varname>stdenv.lib.platforms</varname> defines
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/lib/systems/doubles.nix">
various common lists</link> of platforms types.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>hydraPlatforms</varname></term>
<listitem><para>The list of Nix platform types for which the Hydra
instance at <literal>hydra.nixos.org</literal> will build the
package. (Hydra is the Nix-based continuous build system.) It
defaults to the value of <varname>meta.platforms</varname>. Thus,
the only reason to set <varname>meta.hydraPlatforms</varname> is
if you want <literal>hydra.nixos.org</literal> to build the
package on a subset of <varname>meta.platforms</varname>, or not
at all, e.g.
Attribute Set <varname>stdenv.lib.platforms</varname> defines
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/lib/systems/doubles.nix">
various common lists</link> of platforms types.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>hydraPlatforms</varname>
</term>
<listitem>
<para>
The list of Nix platform types for which the Hydra instance at
<literal>hydra.nixos.org</literal> will build the package. (Hydra is the
Nix-based continuous build system.) It defaults to the value of
<varname>meta.platforms</varname>. Thus, the only reason to set
<varname>meta.hydraPlatforms</varname> is if you want
<literal>hydra.nixos.org</literal> to build the package on a subset of
<varname>meta.platforms</varname>, or not at all, e.g.
<programlisting>
meta.platforms = stdenv.lib.platforms.linux;
meta.hydraPlatforms = [];
</programlisting>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>broken</varname>
</term>
<listitem>
<para>
If set to <literal>true</literal>, the package is marked as “broken”,
meaning that it won’t show up in <literal>nix-env -qa</literal>, and
cannot be built or installed. Such packages should be removed from
Nixpkgs eventually unless they are fixed.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>updateWalker</varname>
</term>
<listitem>
<para>
If set to <literal>true</literal>, the package is tested to be updated
correctly by the <literal>update-walker.sh</literal> script without
additional settings. Such packages have <varname>meta.version</varname>
set and their homepage (or the page specified by
<varname>meta.downloadPage</varname>) contains a direct link to the
package tarball.
</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section xml:id="sec-meta-license">
<title>Licenses</title>
</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>broken</varname></term>
<listitem><para>If set to <literal>true</literal>, the package is
marked as “broken”, meaning that it won’t show up in
<literal>nix-env -qa</literal>, and cannot be built or installed.
Such packages should be removed from Nixpkgs eventually unless
they are fixed.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>updateWalker</varname></term>
<listitem><para>If set to <literal>true</literal>, the package is
tested to be updated correctly by the <literal>update-walker.sh</literal>
script without additional settings. Such packages have
<varname>meta.version</varname> set and their homepage (or
the page specified by <varname>meta.downloadPage</varname>) contains
a direct link to the package tarball.</para></listitem>
</varlistentry>
</variablelist>
</section>
<section xml:id="sec-meta-license"><title>Licenses</title>
<para>The <varname>meta.license</varname> attribute should preferrably contain
a value from <varname>stdenv.lib.licenses</varname> defined in
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/lib/licenses.nix">
<filename>nixpkgs/lib/licenses.nix</filename></link>,
or in-place license description of the same format if the license is
unlikely to be useful in another expression.</para>
<para>Although it's typically better to indicate the specific license,
a few generic options are available:
<variablelist>
<varlistentry>
<term><varname>stdenv.lib.licenses.free</varname>,
<varname>"free"</varname></term>
<listitem><para>Catch-all for free software licenses not listed
above.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>stdenv.lib.licenses.unfreeRedistributable</varname>,
<varname>"unfree-redistributable"</varname></term>
<listitem><para>Unfree package that can be redistributed in binary
form. That is, it’s legal to redistribute the
<emphasis>output</emphasis> of the derivation. This means that
the package can be included in the Nixpkgs
channel.</para>
<para>Sometimes proprietary software can only be redistributed
unmodified. Make sure the builder doesn’t actually modify the
original binaries; otherwise we’re breaking the license. For
instance, the NVIDIA X11 drivers can be redistributed unmodified,
but our builder applies <command>patchelf</command> to make them
work. Thus, its license is <varname>"unfree"</varname> and it
cannot be included in the Nixpkgs channel.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>stdenv.lib.licenses.unfree</varname>,
<varname>"unfree"</varname></term>
<listitem><para>Unfree package that cannot be redistributed. You
can build it yourself, but you cannot redistribute the output of
the derivation. Thus it cannot be included in the Nixpkgs
channel.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>stdenv.lib.licenses.unfreeRedistributableFirmware</varname>,
<varname>"unfree-redistributable-firmware"</varname></term>
<listitem><para>This package supplies unfree, redistributable
firmware. This is a separate value from
<varname>unfree-redistributable</varname> because not everybody
cares whether firmware is free.</para></listitem>
</varlistentry>
</variablelist>
</para>
</section>
<para>
The <varname>meta.license</varname> attribute should preferrably contain a
value from <varname>stdenv.lib.licenses</varname> defined in
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/lib/licenses.nix">
<filename>nixpkgs/lib/licenses.nix</filename></link>, or in-place license
description of the same format if the license is unlikely to be useful in
another expression.
</para>
<para>
Although it's typically better to indicate the specific license, a few
generic options are available:
<variablelist>
<varlistentry>
<term><varname>stdenv.lib.licenses.free</varname>,
<varname>"free"</varname>
</term>
<listitem>
<para>
Catch-all for free software licenses not listed above.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>stdenv.lib.licenses.unfreeRedistributable</varname>,
<varname>"unfree-redistributable"</varname>
</term>
<listitem>
<para>
Unfree package that can be redistributed in binary form. That is, it’s
legal to redistribute the <emphasis>output</emphasis> of the derivation.
This means that the package can be included in the Nixpkgs channel.
</para>
<para>
Sometimes proprietary software can only be redistributed unmodified.
Make sure the builder doesn’t actually modify the original binaries;
otherwise we’re breaking the license. For instance, the NVIDIA X11
drivers can be redistributed unmodified, but our builder applies
<command>patchelf</command> to make them work. Thus, its license is
<varname>"unfree"</varname> and it cannot be included in the Nixpkgs
channel.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>stdenv.lib.licenses.unfree</varname>,
<varname>"unfree"</varname>
</term>
<listitem>
<para>
Unfree package that cannot be redistributed. You can build it yourself,
but you cannot redistribute the output of the derivation. Thus it cannot
be included in the Nixpkgs channel.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>stdenv.lib.licenses.unfreeRedistributableFirmware</varname>,
<varname>"unfree-redistributable-firmware"</varname>
</term>
<listitem>
<para>
This package supplies unfree, redistributable firmware. This is a
separate value from <varname>unfree-redistributable</varname> because
not everybody cares whether firmware is free.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</section>
</chapter>

380
doc/multiple-output.xml
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@ -5,105 +5,319 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-multiple-output">
<title>Multiple-output packages</title>
<section>
<title>Introduction</title>
<title>Multiple-output packages</title>
<para>
The Nix language allows a derivation to produce multiple outputs, which is
similar to what is utilized by other Linux distribution packaging systems.
The outputs reside in separate nix store paths, so they can be mostly
handled independently of each other, including passing to build inputs,
garbage collection or binary substitution. The exception is that building
from source always produces all the outputs.
</para>
<section><title>Introduction</title>
<para>The Nix language allows a derivation to produce multiple outputs, which is similar to what is utilized by other Linux distribution packaging systems. The outputs reside in separate nix store paths, so they can be mostly handled independently of each other, including passing to build inputs, garbage collection or binary substitution. The exception is that building from source always produces all the outputs.</para>
<para>The main motivation is to save disk space by reducing runtime closure sizes; consequently also sizes of substituted binaries get reduced. Splitting can be used to have more granular runtime dependencies, for example the typical reduction is to split away development-only files, as those are typically not needed during runtime. As a result, closure sizes of many packages can get reduced to a half or even much less.</para>
<note><para>The reduction effects could be instead achieved by building the parts in completely separate derivations. That would often additionally reduce build-time closures, but it tends to be much harder to write such derivations, as build systems typically assume all parts are being built at once. This compromise approach of single source package producing multiple binary packages is also utilized often by rpm and deb.</para></note>
</section>
<para>
The main motivation is to save disk space by reducing runtime closure sizes;
consequently also sizes of substituted binaries get reduced. Splitting can
be used to have more granular runtime dependencies, for example the typical
reduction is to split away development-only files, as those are typically
not needed during runtime. As a result, closure sizes of many packages can
get reduced to a half or even much less.
</para>
<note>
<para>
The reduction effects could be instead achieved by building the parts in
completely separate derivations. That would often additionally reduce
build-time closures, but it tends to be much harder to write such
derivations, as build systems typically assume all parts are being built at
once. This compromise approach of single source package producing multiple
binary packages is also utilized often by rpm and deb.
</para>
</note>
</section>
<section>
<title>Installing a split package</title>
<para>
When installing a package via <varname>systemPackages</varname> or
<command>nix-env</command> you have several options:
</para>
<section><title>Installing a split package</title>
<para>When installing a package via <varname>systemPackages</varname> or <command>nix-env</command> you have several options:</para>
<itemizedlist>
<listitem><para>You can install particular outputs explicitly, as each is available in the Nix language as an attribute of the package. The <varname>outputs</varname> attribute contains a list of output names.</para></listitem>
<listitem><para>You can let it use the default outputs. These are handled by <varname>meta.outputsToInstall</varname> attribute that contains a list of output names.</para>
<para>TODO: more about tweaking the attribute, etc.</para></listitem>
<listitem><para>NixOS provides configuration option <varname>environment.extraOutputsToInstall</varname> that allows adding extra outputs of <varname>environment.systemPackages</varname> atop the default ones. It's mainly meant for documentation and debug symbols, and it's also modified by specific options.</para>
<note><para>At this moment there is no similar configurability for packages installed by <command>nix-env</command>. You can still use approach from <xref linkend="sec-modify-via-packageOverrides" /> to override <varname>meta.outputsToInstall</varname> attributes, but that's a rather inconvenient way.</para></note>
</listitem>
<listitem>
<para>
You can install particular outputs explicitly, as each is available in the
Nix language as an attribute of the package. The
<varname>outputs</varname> attribute contains a list of output names.
</para>
</listitem>
<listitem>
<para>
You can let it use the default outputs. These are handled by
<varname>meta.outputsToInstall</varname> attribute that contains a list of
output names.
</para>
<para>
TODO: more about tweaking the attribute, etc.
</para>
</listitem>
<listitem>
<para>
NixOS provides configuration option
<varname>environment.extraOutputsToInstall</varname> that allows adding
extra outputs of <varname>environment.systemPackages</varname> atop the
default ones. It's mainly meant for documentation and debug symbols, and
it's also modified by specific options.
</para>
<note>
<para>
At this moment there is no similar configurability for packages installed
by <command>nix-env</command>. You can still use approach from
<xref linkend="sec-modify-via-packageOverrides" /> to override
<varname>meta.outputsToInstall</varname> attributes, but that's a rather
inconvenient way.
</para>
</note>
</listitem>
</itemizedlist>
</section>
</section>
<section>
<title>Using a split package</title>
<section><title>Using a split package</title>
<para>In the Nix language the individual outputs can be reached explicitly as attributes, e.g. <varname>coreutils.info</varname>, but the typical case is just using packages as build inputs.</para>
<para>When a multiple-output derivation gets into a build input of another derivation, the <varname>dev</varname> output is added if it exists, otherwise the first output is added. In addition to that, <varname>propagatedBuildOutputs</varname> of that package which by default contain <varname>$outputBin</varname> and <varname>$outputLib</varname> are also added. (See <xref linkend="multiple-output-file-type-groups" />.)</para>
</section>
<para>
In the Nix language the individual outputs can be reached explicitly as
attributes, e.g. <varname>coreutils.info</varname>, but the typical case is
just using packages as build inputs.
</para>
<para>
When a multiple-output derivation gets into a build input of another
derivation, the <varname>dev</varname> output is added if it exists,
otherwise the first output is added. In addition to that,
<varname>propagatedBuildOutputs</varname> of that package which by default
contain <varname>$outputBin</varname> and <varname>$outputLib</varname> are
also added. (See <xref linkend="multiple-output-file-type-groups" />.)
</para>
</section>
<section>
<title>Writing a split derivation</title>
<section><title>Writing a split derivation</title>
<para>Here you find how to write a derivation that produces multiple outputs.</para>
<para>In nixpkgs there is a framework supporting multiple-output derivations. It tries to cover most cases by default behavior. You can find the source separated in &lt;<filename>nixpkgs/pkgs/build-support/setup-hooks/multiple-outputs.sh</filename>&gt;; it's relatively well-readable. The whole machinery is triggered by defining the <varname>outputs</varname> attribute to contain the list of desired output names (strings).</para>
<programlisting>outputs = [ "bin" "dev" "out" "doc" ];</programlisting>
<para>Often such a single line is enough. For each output an equally named environment variable is passed to the builder and contains the path in nix store for that output. Typically you also want to have the main <varname>out</varname> output, as it catches any files that didn't get elsewhere.</para>
<note><para>There is a special handling of the <varname>debug</varname> output, described at <xref linkend="stdenv-separateDebugInfo" />.</para></note>
<para>
Here you find how to write a derivation that produces multiple outputs.
</para>
<para>
In nixpkgs there is a framework supporting multiple-output derivations. It
tries to cover most cases by default behavior. You can find the source
separated in
&lt;<filename>nixpkgs/pkgs/build-support/setup-hooks/multiple-outputs.sh</filename>&gt;;
it's relatively well-readable. The whole machinery is triggered by defining
the <varname>outputs</varname> attribute to contain the list of desired
output names (strings).
</para>
<programlisting>outputs = [ "bin" "dev" "out" "doc" ];</programlisting>
<para>
Often such a single line is enough. For each output an equally named
environment variable is passed to the builder and contains the path in nix
store for that output. Typically you also want to have the main
<varname>out</varname> output, as it catches any files that didn't get
elsewhere.
</para>
<note>
<para>
There is a special handling of the <varname>debug</varname> output,
described at <xref linkend="stdenv-separateDebugInfo" />.
</para>
</note>
<section xml:id="multiple-output-file-binaries-first-convention">
<title><quote>Binaries first</quote></title>
<para>A commonly adopted convention in <literal>nixpkgs</literal> is that executables provided by the package are contained within its first output. This convention allows the dependent packages to reference the executables provided by packages in a uniform manner. For instance, provided with the knowledge that the <literal>perl</literal> package contains a <literal>perl</literal> executable it can be referenced as <literal>${pkgs.perl}/bin/perl</literal> within a Nix derivation that needs to execute a Perl script.</para>
<para>The <literal>glibc</literal> package is a deliberate single exception to the <quote>binaries first</quote> convention. The <literal>glibc</literal> has <literal>libs</literal> as its first output allowing the libraries provided by <literal>glibc</literal> to be referenced directly (e.g. <literal>${stdenv.glibc}/lib/ld-linux-x86-64.so.2</literal>). The executables provided by <literal>glibc</literal> can be accessed via its <literal>bin</literal> attribute (e.g. <literal>${stdenv.glibc.bin}/bin/ldd</literal>).</para>
<para>The reason for why <literal>glibc</literal> deviates from the convention is because referencing a library provided by <literal>glibc</literal> is a very common operation among Nix packages. For instance, third-party executables packaged by Nix are typically patched and relinked with the relevant version of <literal>glibc</literal> libraries from Nix packages (please see the documentation on <link xlink:href="https://nixos.org/patchelf.html">patchelf</link> for more details).</para>
<title><quote>Binaries first</quote></title>
<para>
A commonly adopted convention in <literal>nixpkgs</literal> is that
executables provided by the package are contained within its first output.
This convention allows the dependent packages to reference the executables
provided by packages in a uniform manner. For instance, provided with the
knowledge that the <literal>perl</literal> package contains a
<literal>perl</literal> executable it can be referenced as
<literal>${pkgs.perl}/bin/perl</literal> within a Nix derivation that needs
to execute a Perl script.
</para>
<para>
The <literal>glibc</literal> package is a deliberate single exception to
the <quote>binaries first</quote> convention. The <literal>glibc</literal>
has <literal>libs</literal> as its first output allowing the libraries
provided by <literal>glibc</literal> to be referenced directly (e.g.
<literal>${stdenv.glibc}/lib/ld-linux-x86-64.so.2</literal>). The
executables provided by <literal>glibc</literal> can be accessed via its
<literal>bin</literal> attribute (e.g.
<literal>${stdenv.glibc.bin}/bin/ldd</literal>).
</para>
<para>
The reason for why <literal>glibc</literal> deviates from the convention is
because referencing a library provided by <literal>glibc</literal> is a
very common operation among Nix packages. For instance, third-party
executables packaged by Nix are typically patched and relinked with the
relevant version of <literal>glibc</literal> libraries from Nix packages
(please see the documentation on
<link xlink:href="https://nixos.org/patchelf.html">patchelf</link> for more
details).
</para>
</section>
<section xml:id="multiple-output-file-type-groups">
<title>File type groups</title>
<para>The support code currently recognizes some particular kinds of outputs and either instructs the build system of the package to put files into their desired outputs or it moves the files during the fixup phase. Each group of file types has an <varname>outputFoo</varname> variable specifying the output name where they should go. If that variable isn't defined by the derivation writer, it is guessed &ndash; a default output name is defined, falling back to other possibilities if the output isn't defined.</para>
<variablelist>
<title>File type groups</title>
<varlistentry><term><varname>
$outputDev</varname></term><listitem><para>
is for development-only files. These include C(++) headers, pkg-config, cmake and aclocal files. They go to <varname>dev</varname> or <varname>out</varname> by default.
</para></listitem>
</varlistentry>
<para>
The support code currently recognizes some particular kinds of outputs and
either instructs the build system of the package to put files into their
desired outputs or it moves the files during the fixup phase. Each group of
file types has an <varname>outputFoo</varname> variable specifying the
output name where they should go. If that variable isn't defined by the
derivation writer, it is guessed &ndash; a default output name is defined,
falling back to other possibilities if the output isn't defined.
</para>
<varlistentry><term><varname>
$outputBin</varname></term><listitem><para>
is meant for user-facing binaries, typically residing in bin/. They go to <varname>bin</varname> or <varname>out</varname> by default.
</para></listitem></varlistentry>
<varlistentry><term><varname>
$outputLib</varname></term><listitem><para>
is meant for libraries, typically residing in <filename>lib/</filename> and <filename>libexec/</filename>. They go to <varname>lib</varname> or <varname>out</varname> by default.
</para></listitem></varlistentry>
<varlistentry><term><varname>
$outputDoc</varname></term><listitem><para>
is for user documentation, typically residing in <filename>share/doc/</filename>. It goes to <varname>doc</varname> or <varname>out</varname> by default.
</para></listitem></varlistentry>
<varlistentry><term><varname>
$outputDevdoc</varname></term><listitem><para>
is for <emphasis>developer</emphasis> documentation. Currently we count gtk-doc and devhelp books in there. It goes to <varname>devdoc</varname> or is removed (!) by default. This is because e.g. gtk-doc tends to be rather large and completely unused by nixpkgs users.
</para></listitem></varlistentry>
<varlistentry><term><varname>
$outputMan</varname></term><listitem><para>
is for man pages (except for section 3). They go to <varname>man</varname> or <varname>$outputBin</varname> by default.
</para></listitem></varlistentry>
<varlistentry><term><varname>
$outputDevman</varname></term><listitem><para>
is for section 3 man pages. They go to <varname>devman</varname> or <varname>$outputMan</varname> by default.
</para></listitem></varlistentry>
<varlistentry><term><varname>
$outputInfo</varname></term><listitem><para>
is for info pages. They go to <varname>info</varname> or <varname>$outputBin</varname> by default.
</para></listitem></varlistentry>
</variablelist>
<variablelist>
<varlistentry>
<term><varname>
$outputDev</varname>
</term>
<listitem>
<para>
is for development-only files. These include C(++) headers, pkg-config,
cmake and aclocal files. They go to <varname>dev</varname> or
<varname>out</varname> by default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>
$outputBin</varname>
</term>
<listitem>
<para>
is meant for user-facing binaries, typically residing in bin/. They go
to <varname>bin</varname> or <varname>out</varname> by default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>
$outputLib</varname>
</term>
<listitem>
<para>
is meant for libraries, typically residing in <filename>lib/</filename>
and <filename>libexec/</filename>. They go to <varname>lib</varname> or
<varname>out</varname> by default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>
$outputDoc</varname>
</term>
<listitem>
<para>
is for user documentation, typically residing in
<filename>share/doc/</filename>. It goes to <varname>doc</varname> or
<varname>out</varname> by default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>
$outputDevdoc</varname>
</term>
<listitem>
<para>
is for <emphasis>developer</emphasis> documentation. Currently we count
gtk-doc and devhelp books in there. It goes to <varname>devdoc</varname>
or is removed (!) by default. This is because e.g. gtk-doc tends to be
rather large and completely unused by nixpkgs users.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>
$outputMan</varname>
</term>
<listitem>
<para>
is for man pages (except for section 3). They go to
<varname>man</varname> or <varname>$outputBin</varname> by default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>
$outputDevman</varname>
</term>
<listitem>
<para>
is for section 3 man pages. They go to <varname>devman</varname> or
<varname>$outputMan</varname> by default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>
$outputInfo</varname>
</term>
<listitem>
<para>
is for info pages. They go to <varname>info</varname> or
<varname>$outputBin</varname> by default.
</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section><title>Common caveats</title>
<itemizedlist>
<listitem><para>Some configure scripts don't like some of the parameters passed by default by the framework, e.g. <literal>--docdir=/foo/bar</literal>. You can disable this by setting <literal>setOutputFlags = false;</literal>.</para></listitem>
<listitem><para>The outputs of a single derivation can retain references to each other, but note that circular references are not allowed. (And each strongly-connected component would act as a single output anyway.)</para></listitem>
<listitem><para>Most of split packages contain their core functionality in libraries. These libraries tend to refer to various kind of data that typically gets into <varname>out</varname>, e.g. locale strings, so there is often no advantage in separating the libraries into <varname>lib</varname>, as keeping them in <varname>out</varname> is easier.</para></listitem>
<listitem><para>Some packages have hidden assumptions on install paths, which complicates splitting.</para></listitem>
</itemizedlist>
<section>
<title>Common caveats</title>
<itemizedlist>
<listitem>
<para>
Some configure scripts don't like some of the parameters passed by
default by the framework, e.g. <literal>--docdir=/foo/bar</literal>. You
can disable this by setting <literal>setOutputFlags = false;</literal>.
</para>
</listitem>
<listitem>
<para>
The outputs of a single derivation can retain references to each other,
but note that circular references are not allowed. (And each
strongly-connected component would act as a single output anyway.)
</para>
</listitem>
<listitem>
<para>
Most of split packages contain their core functionality in libraries.
These libraries tend to refer to various kind of data that typically gets
into <varname>out</varname>, e.g. locale strings, so there is often no
advantage in separating the libraries into <varname>lib</varname>, as
keeping them in <varname>out</varname> is easier.
</para>
</listitem>
<listitem>
<para>
Some packages have hidden assumptions on install paths, which complicates
splitting.
</para>
</listitem>
</itemizedlist>
</section>
</section><!--Writing a split derivation-->
</section>
<!--Writing a split derivation-->
</chapter>

240
doc/overlays.xml
View File

@ -1,95 +1,117 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-overlays">
<title>Overlays</title>
<para>This chapter describes how to extend and change Nixpkgs packages using
overlays. Overlays are used to add layers in the fix-point used by Nixpkgs
to compose the set of all packages.</para>
<para>Nixpkgs can be configured with a list of overlays, which are
applied in order. This means that the order of the overlays can be significant
if multiple layers override the same package.</para>
<title>Overlays</title>
<para>
This chapter describes how to extend and change Nixpkgs packages using
overlays. Overlays are used to add layers in the fix-point used by Nixpkgs to
compose the set of all packages.
</para>
<para>
Nixpkgs can be configured with a list of overlays, which are applied in
order. This means that the order of the overlays can be significant if
multiple layers override the same package.
</para>
<!--============================================================-->
<section xml:id="sec-overlays-install">
<title>Installing overlays</title>
<section xml:id="sec-overlays-install">
<title>Installing overlays</title>
<para>
The list of overlays is determined as follows.
</para>
<para>The list of overlays is determined as follows.</para>
<para>
If the <varname>overlays</varname> argument is not provided explicitly, we
look for overlays in a path. The path is determined as follows:
<orderedlist>
<listitem>
<para>
First, if an <varname>overlays</varname> argument to the nixpkgs function
itself is given, then that is used.
</para>
<para>
This can be passed explicitly when importing nipxkgs, for example
<literal>import &lt;nixpkgs> { overlays = [ overlay1 overlay2 ];
}</literal>.
</para>
</listitem>
<listitem>
<para>
Otherwise, if the Nix path entry <literal>&lt;nixpkgs-overlays></literal>
exists, we look for overlays at that path, as described below.
</para>
<para>
See the section on <literal>NIX_PATH</literal> in the Nix manual for more
details on how to set a value for
<literal>&lt;nixpkgs-overlays>.</literal>
</para>
</listitem>
<listitem>
<para>
If one of <filename>~/.config/nixpkgs/overlays.nix</filename> and
<filename>~/.config/nixpkgs/overlays/</filename> exists, then we look for
overlays at that path, as described below. It is an error if both exist.
</para>
</listitem>
</orderedlist>
</para>
<para>If the <varname>overlays</varname> argument is not provided explicitly, we look for overlays in a path. The path
is determined as follows:
<para>
If we are looking for overlays at a path, then there are two cases:
<itemizedlist>
<listitem>
<para>
If the path is a file, then the file is imported as a Nix expression and
used as the list of overlays.
</para>
</listitem>
<listitem>
<para>
If the path is a directory, then we take the content of the directory,
order it lexicographically, and attempt to interpret each as an overlay
by:
<itemizedlist>
<listitem>
<para>
Importing the file, if it is a <literal>.nix</literal> file.
</para>
</listitem>
<listitem>
<para>
Importing a top-level <filename>default.nix</filename> file, if it is
a directory.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</para>
<orderedlist>
<listitem>
<para>First, if an <varname>overlays</varname> argument to the nixpkgs function itself is given,
then that is used.</para>
<para>This can be passed explicitly when importing nipxkgs, for example
<literal>import &lt;nixpkgs> { overlays = [ overlay1 overlay2 ]; }</literal>.</para>
</listitem>
<listitem>
<para>Otherwise, if the Nix path entry <literal>&lt;nixpkgs-overlays></literal> exists, we look for overlays
at that path, as described below.</para>
<para>See the section on <literal>NIX_PATH</literal> in the Nix manual for more details on how to
set a value for <literal>&lt;nixpkgs-overlays>.</literal></para>
</listitem>
<listitem>
<para>If one of <filename>~/.config/nixpkgs/overlays.nix</filename> and
<filename>~/.config/nixpkgs/overlays/</filename> exists, then we look for overlays at that path, as
described below. It is an error if both exist.</para>
</listitem>
</orderedlist>
</para>
<para>If we are looking for overlays at a path, then there are two cases:
<itemizedlist>
<listitem>
<para>If the path is a file, then the file is imported as a Nix expression and used as the list of
overlays.</para>
</listitem>
<listitem>
<para>If the path is a directory, then we take the content of the directory, order it
lexicographically, and attempt to interpret each as an overlay by:
<itemizedlist>
<listitem>
<para>Importing the file, if it is a <literal>.nix</literal> file.</para>
</listitem>
<listitem>
<para>Importing a top-level <filename>default.nix</filename> file, if it is a directory.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</para>
<para>On a NixOS system the value of the <literal>nixpkgs.overlays</literal> option, if present,
is passed to the system Nixpkgs directly as an argument. Note that this does not affect the overlays for
non-NixOS operations (e.g. <literal>nix-env</literal>), which are looked up independently.</para>
<para>The <filename>overlays.nix</filename> option therefore provides a convenient way to use the same
overlays for a NixOS system configuration and user configuration: the same file can be used
as <filename>overlays.nix</filename> and imported as the value of <literal>nixpkgs.overlays</literal>.</para>
</section>
<para>
On a NixOS system the value of the <literal>nixpkgs.overlays</literal>
option, if present, is passed to the system Nixpkgs directly as an argument.
Note that this does not affect the overlays for non-NixOS operations (e.g.
<literal>nix-env</literal>), which are looked up independently.
</para>
<para>
The <filename>overlays.nix</filename> option therefore provides a convenient
way to use the same overlays for a NixOS system configuration and user
configuration: the same file can be used as
<filename>overlays.nix</filename> and imported as the value of
<literal>nixpkgs.overlays</literal>.
</para>
</section>
<!--============================================================-->
<section xml:id="sec-overlays-definition">
<title>Defining overlays</title>
<section xml:id="sec-overlays-definition">
<title>Defining overlays</title>
<para>Overlays are Nix functions which accept two arguments,
conventionally called <varname>self</varname> and <varname>super</varname>,
and return a set of packages. For example, the following is a valid overlay.</para>
<para>
Overlays are Nix functions which accept two arguments, conventionally called
<varname>self</varname> and <varname>super</varname>, and return a set of
packages. For example, the following is a valid overlay.
</para>
<programlisting>
self: super:
@ -104,31 +126,39 @@ self: super:
}
</programlisting>
<para>The first argument (<varname>self</varname>) corresponds to the final package
set. You should use this set for the dependencies of all packages specified in your
overlay. For example, all the dependencies of <varname>rr</varname> in the example above come
from <varname>self</varname>, as well as the overridden dependencies used in the
<varname>boost</varname> override.</para>
<para>
The first argument (<varname>self</varname>) corresponds to the final
package set. You should use this set for the dependencies of all packages
specified in your overlay. For example, all the dependencies of
<varname>rr</varname> in the example above come from
<varname>self</varname>, as well as the overridden dependencies used in the
<varname>boost</varname> override.
</para>
<para>The second argument (<varname>super</varname>)
corresponds to the result of the evaluation of the previous stages of
Nixpkgs. It does not contain any of the packages added by the current
overlay, nor any of the following overlays. This set should be used either
to refer to packages you wish to override, or to access functions defined
in Nixpkgs. For example, the original recipe of <varname>boost</varname>
in the above example, comes from <varname>super</varname>, as well as the
<varname>callPackage</varname> function.</para>
<para>
The second argument (<varname>super</varname>) corresponds to the result of
the evaluation of the previous stages of Nixpkgs. It does not contain any of
the packages added by the current overlay, nor any of the following
overlays. This set should be used either to refer to packages you wish to
override, or to access functions defined in Nixpkgs. For example, the
original recipe of <varname>boost</varname> in the above example, comes from
<varname>super</varname>, as well as the <varname>callPackage</varname>
function.
</para>
<para>The value returned by this function should be a set similar to
<filename>pkgs/top-level/all-packages.nix</filename>, containing
overridden and/or new packages.</para>
<para>Overlays are similar to other methods for customizing Nixpkgs, in particular
the <literal>packageOverrides</literal> attribute described in <xref linkend="sec-modify-via-packageOverrides"/>.
Indeed, <literal>packageOverrides</literal> acts as an overlay with only the
<varname>super</varname> argument. It is therefore appropriate for basic use,
but overlays are more powerful and easier to distribute.</para>
</section>
<para>
The value returned by this function should be a set similar to
<filename>pkgs/top-level/all-packages.nix</filename>, containing overridden
and/or new packages.
</para>
<para>
Overlays are similar to other methods for customizing Nixpkgs, in particular
the <literal>packageOverrides</literal> attribute described in
<xref linkend="sec-modify-via-packageOverrides"/>. Indeed,
<literal>packageOverrides</literal> acts as an overlay with only the
<varname>super</varname> argument. It is therefore appropriate for basic
use, but overlays are more powerful and easier to distribute.
</para>
</section>
</chapter>

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@ -1,27 +1,25 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-platform-nodes">
<title>Platform Notes</title>
<section xml:id="sec-darwin">
<title>Darwin (macOS)</title>
<title>Platform Notes</title>
<para>
Some common issues when packaging software for darwin:
</para>
<section xml:id="sec-darwin">
<title>Darwin (macOS)</title>
<para>Some common issues when packaging software for darwin:</para>
<itemizedlist>
<listitem>
<itemizedlist>
<listitem>
<para>
The darwin <literal>stdenv</literal> uses clang instead of gcc.
When referring to the compiler <varname>$CC</varname> or <command>cc</command>
will work in both cases. Some builds hardcode gcc/g++ in their
build scripts, that can usually be fixed with using something
like <literal>makeFlags = [ "CC=cc" ];</literal> or by patching
the build scripts.
The darwin <literal>stdenv</literal> uses clang instead of gcc. When
referring to the compiler <varname>$CC</varname> or <command>cc</command>
will work in both cases. Some builds hardcode gcc/g++ in their build
scripts, that can usually be fixed with using something like
<literal>makeFlags = [ "CC=cc" ];</literal> or by patching the build
scripts.
</para>
<programlisting>
<programlisting>
stdenv.mkDerivation {
name = "libfoo-1.2.3";
# ...
@ -30,36 +28,33 @@
'';
}
</programlisting>
</listitem>
<listitem>
</listitem>
<listitem>
<para>
On darwin libraries are linked using absolute paths, libraries
are resolved by their <literal>install_name</literal> at link
time. Sometimes packages won't set this correctly causing the
library lookups to fail at runtime. This can be fixed by adding
extra linker flags or by running <command>install_name_tool -id</command>
during the <function>fixupPhase</function>.
On darwin libraries are linked using absolute paths, libraries are
resolved by their <literal>install_name</literal> at link time. Sometimes
packages won't set this correctly causing the library lookups to fail at
runtime. This can be fixed by adding extra linker flags or by running
<command>install_name_tool -id</command> during the
<function>fixupPhase</function>.
</para>
<programlisting>
<programlisting>
stdenv.mkDerivation {
name = "libfoo-1.2.3";
# ...
makeFlags = stdenv.lib.optional stdenv.isDarwin "LDFLAGS=-Wl,-install_name,$(out)/lib/libfoo.dylib";
}
</programlisting>
</listitem>
<listitem>
</listitem>
<listitem>
<para>
Some packages assume xcode is available and use <command>xcrun</command>
to resolve build tools like <command>clang</command>, etc.
This causes errors like <code>xcode-select: error: no developer tools were found at '/Applications/Xcode.app'</code>
while the build doesn't actually depend on xcode.
Some packages assume xcode is available and use <command>xcrun</command>
to resolve build tools like <command>clang</command>, etc. This causes
errors like <code>xcode-select: error: no developer tools were found at
'/Applications/Xcode.app'</code> while the build doesn't actually depend
on xcode.
</para>
<programlisting>
<programlisting>
stdenv.mkDerivation {
name = "libfoo-1.2.3";
# ...
@ -69,15 +64,12 @@
'';
}
</programlisting>
<para>
The package <literal>xcbuild</literal> can be used to build projects
that really depend on Xcode, however projects that build some kind of
graphical interface won't work without using Xcode in an impure way.
The package <literal>xcbuild</literal> can be used to build projects that
really depend on Xcode, however projects that build some kind of graphical
interface won't work without using Xcode in an impure way.
</para>
</listitem>
</itemizedlist>
</section>
</listitem>
</itemizedlist>
</section>
</chapter>

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@ -1,223 +1,219 @@
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-quick-start">
<title>Quick Start to Adding a Package</title>
<para>To add a package to Nixpkgs:
<orderedlist>
<listitem>
<para>Checkout the Nixpkgs source tree:
<title>Quick Start to Adding a Package</title>
<para>
To add a package to Nixpkgs:
<orderedlist>
<listitem>
<para>
Checkout the Nixpkgs source tree:
<screen>
$ git clone git://github.com/NixOS/nixpkgs.git
$ cd nixpkgs</screen>
</para>
</listitem>
<listitem>
<para>Find a good place in the Nixpkgs tree to add the Nix
expression for your package. For instance, a library package
typically goes into
<filename>pkgs/development/libraries/<replaceable>pkgname</replaceable></filename>,
while a web browser goes into
<filename>pkgs/applications/networking/browsers/<replaceable>pkgname</replaceable></filename>.
See <xref linkend="sec-organisation" /> for some hints on the tree
organisation. Create a directory for your package, e.g.
</listitem>
<listitem>
<para>
Find a good place in the Nixpkgs tree to add the Nix expression for your
package. For instance, a library package typically goes into
<filename>pkgs/development/libraries/<replaceable>pkgname</replaceable></filename>,
while a web browser goes into
<filename>pkgs/applications/networking/browsers/<replaceable>pkgname</replaceable></filename>.
See <xref linkend="sec-organisation" /> for some hints on the tree
organisation. Create a directory for your package, e.g.
<screen>
$ mkdir pkgs/development/libraries/libfoo</screen>
</para>
</listitem>
<listitem>
<para>In the package directory, create a Nix expression — a piece
of code that describes how to build the package. In this case, it
should be a <emphasis>function</emphasis> that is called with the
package dependencies as arguments, and returns a build of the
package in the Nix store. The expression should usually be called
<filename>default.nix</filename>.
</listitem>
<listitem>
<para>
In the package directory, create a Nix expression — a piece of code that
describes how to build the package. In this case, it should be a
<emphasis>function</emphasis> that is called with the package dependencies
as arguments, and returns a build of the package in the Nix store. The
expression should usually be called <filename>default.nix</filename>.
<screen>
$ emacs pkgs/development/libraries/libfoo/default.nix
$ git add pkgs/development/libraries/libfoo/default.nix</screen>
</para>
<para>You can have a look at the existing Nix expressions under
<filename>pkgs/</filename> to see how it’s done. Here are some
good ones:
<itemizedlist>
<listitem>
<para>GNU Hello: <link
<para>
You can have a look at the existing Nix expressions under
<filename>pkgs/</filename> to see how it’s done. Here are some good
ones:
<itemizedlist>
<listitem>
<para>
GNU Hello:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/misc/hello/default.nix"><filename>pkgs/applications/misc/hello/default.nix</filename></link>.
Trivial package, which specifies some <varname>meta</varname>
attributes which is good practice.</para>
</listitem>
<listitem>
<para>GNU cpio: <link
Trivial package, which specifies some <varname>meta</varname>
attributes which is good practice.
</para>
</listitem>
<listitem>
<para>
GNU cpio:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/tools/archivers/cpio/default.nix"><filename>pkgs/tools/archivers/cpio/default.nix</filename></link>.
Also a simple package. The generic builder in
<varname>stdenv</varname> does everything for you. It has
no dependencies beyond <varname>stdenv</varname>.</para>
</listitem>
<listitem>
<para>GNU Multiple Precision arithmetic library (GMP): <link
Also a simple package. The generic builder in <varname>stdenv</varname>
does everything for you. It has no dependencies beyond
<varname>stdenv</varname>.
</para>
</listitem>
<listitem>
<para>
GNU Multiple Precision arithmetic library (GMP):
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/libraries/gmp/5.1.x.nix"><filename>pkgs/development/libraries/gmp/5.1.x.nix</filename></link>.
Also done by the generic builder, but has a dependency on
<varname>m4</varname>.</para>
</listitem>
<listitem>
<para>Pan, a GTK-based newsreader: <link
Also done by the generic builder, but has a dependency on
<varname>m4</varname>.
</para>
</listitem>
<listitem>
<para>
Pan, a GTK-based newsreader:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/networking/newsreaders/pan/default.nix"><filename>pkgs/applications/networking/newsreaders/pan/default.nix</filename></link>.
Has an optional dependency on <varname>gtkspell</varname>,
which is only built if <varname>spellCheck</varname> is
<literal>true</literal>.</para>
</listitem>
<listitem>
<para>Apache HTTPD: <link
Has an optional dependency on <varname>gtkspell</varname>, which is
only built if <varname>spellCheck</varname> is <literal>true</literal>.
</para>
</listitem>
<listitem>
<para>
Apache HTTPD:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/servers/http/apache-httpd/2.4.nix"><filename>pkgs/servers/http/apache-httpd/2.4.nix</filename></link>.
A bunch of optional features, variable substitutions in the
configure flags, a post-install hook, and miscellaneous
hackery.</para>
</listitem>
<listitem>
<para>Thunderbird: <link
A bunch of optional features, variable substitutions in the configure
flags, a post-install hook, and miscellaneous hackery.
</para>
</listitem>
<listitem>
<para>
Thunderbird:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/networking/mailreaders/thunderbird/default.nix"><filename>pkgs/applications/networking/mailreaders/thunderbird/default.nix</filename></link>.
Lots of dependencies.</para>
</listitem>
<listitem>
<para>JDiskReport, a Java utility: <link
Lots of dependencies.
</para>
</listitem>
<listitem>
<para>
JDiskReport, a Java utility:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/tools/misc/jdiskreport/default.nix"><filename>pkgs/tools/misc/jdiskreport/default.nix</filename></link>
(and the <link
(and the
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/tools/misc/jdiskreport/builder.sh">builder</link>).
Nixpkgs doesn’t have a decent <varname>stdenv</varname> for
Java yet so this is pretty ad-hoc.</para>
</listitem>
<listitem>
<para>XML::Simple, a Perl module: <link
Nixpkgs doesn’t have a decent <varname>stdenv</varname> for Java yet
so this is pretty ad-hoc.
</para>
</listitem>
<listitem>
<para>
XML::Simple, a Perl module:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/perl-packages.nix"><filename>pkgs/top-level/perl-packages.nix</filename></link>
(search for the <varname>XMLSimple</varname> attribute).
Most Perl modules are so simple to build that they are
defined directly in <filename>perl-packages.nix</filename>;
no need to make a separate file for them.</para>
</listitem>
<listitem>
<para>Adobe Reader: <link
(search for the <varname>XMLSimple</varname> attribute). Most Perl
modules are so simple to build that they are defined directly in
<filename>perl-packages.nix</filename>; no need to make a separate file
for them.
</para>
</listitem>
<listitem>
<para>
Adobe Reader:
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/misc/adobe-reader/default.nix"><filename>pkgs/applications/misc/adobe-reader/default.nix</filename></link>.
Shows how binary-only packages can be supported. In
particular the <link
Shows how binary-only packages can be supported. In particular the
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/misc/adobe-reader/builder.sh">builder</link>
uses <command>patchelf</command> to set the RUNPATH and ELF
interpreter of the executables so that the right libraries
are found at runtime.</para>
</listitem>
</itemizedlist>
uses <command>patchelf</command> to set the RUNPATH and ELF interpreter
of the executables so that the right libraries are found at runtime.
</para>
</listitem>
</itemizedlist>
</para>
<para>Some notes:
<itemizedlist>
<listitem>
<para>All <varname linkend="chap-meta">meta</varname>
attributes are optional, but it’s still a good idea to
provide at least the <varname>description</varname>,
<varname>homepage</varname> and <varname
linkend="sec-meta-license">license</varname>.</para>
</listitem>
<listitem>
<para>You can use <command>nix-prefetch-url</command> (or similar nix-prefetch-git, etc)
<replaceable>url</replaceable> to get the SHA-256 hash of
source distributions. There are similar commands as <command>nix-prefetch-git</command> and
<command>nix-prefetch-hg</command> available in <literal>nix-prefetch-scripts</literal> package.</para>
</listitem>
<listitem>
<para>A list of schemes for <literal>mirror://</literal>
URLs can be found in <link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/build-support/fetchurl/mirrors.nix"><filename>pkgs/build-support/fetchurl/mirrors.nix</filename></link>.</para>
</listitem>
</itemizedlist>
<para>
Some notes:
<itemizedlist>
<listitem>
<para>
All <varname linkend="chap-meta">meta</varname> attributes are
optional, but it’s still a good idea to provide at least the
<varname>description</varname>, <varname>homepage</varname> and
<varname
linkend="sec-meta-license">license</varname>.
</para>
</listitem>
<listitem>
<para>
You can use <command>nix-prefetch-url</command> (or similar
nix-prefetch-git, etc) <replaceable>url</replaceable> to get the
SHA-256 hash of source distributions. There are similar commands as
<command>nix-prefetch-git</command> and
<command>nix-prefetch-hg</command> available in
<literal>nix-prefetch-scripts</literal> package.
</para>
</listitem>
<listitem>
<para>
A list of schemes for <literal>mirror://</literal> URLs can be found in
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/build-support/fetchurl/mirrors.nix"><filename>pkgs/build-support/fetchurl/mirrors.nix</filename></link>.
</para>
</listitem>
</itemizedlist>
</para>
<para>The exact syntax and semantics of the Nix expression
language, including the built-in function, are described in the
Nix manual in the <link
<para>
The exact syntax and semantics of the Nix expression language, including
the built-in function, are described in the Nix manual in the
<link
xlink:href="http://hydra.nixos.org/job/nix/trunk/tarball/latest/download-by-type/doc/manual/#chap-writing-nix-expressions">chapter
on writing Nix expressions</link>.</para>
</listitem>
<listitem>
<para>Add a call to the function defined in the previous step to
<link
on writing Nix expressions</link>.
</para>
</listitem>
<listitem>
<para>
Add a call to the function defined in the previous step to
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/all-packages.nix"><filename>pkgs/top-level/all-packages.nix</filename></link>
with some descriptive name for the variable,
e.g. <varname>libfoo</varname>.
<screen>
with some descriptive name for the variable, e.g.
<varname>libfoo</varname>.
<screen>
$ emacs pkgs/top-level/all-packages.nix</screen>
</para>
<para>The attributes in that file are sorted by category (like
“Development / Libraries”) that more-or-less correspond to the
directory structure of Nixpkgs, and then by attribute name.</para>
</listitem>
<listitem>
<para>To test whether the package builds, run the following command
from the root of the nixpkgs source tree:
<screen>
<para>
The attributes in that file are sorted by category (like “Development /
Libraries”) that more-or-less correspond to the directory structure of
Nixpkgs, and then by attribute name.
</para>
</listitem>
<listitem>
<para>
To test whether the package builds, run the following command from the
root of the nixpkgs source tree:
<screen>
$ nix-build -A libfoo</screen>
where <varname>libfoo</varname> should be the variable name
defined in the previous step. You may want to add the flag
<option>-K</option> to keep the temporary build directory in case
something fails. If the build succeeds, a symlink
<filename>./result</filename> to the package in the Nix store is
created.</para>
</listitem>
<listitem>
<para>If you want to install the package into your profile
(optional), do
<screen>
$ nix-env -f . -iA libfoo</screen>
where <varname>libfoo</varname> should be the variable name defined in the
previous step. You may want to add the flag <option>-K</option> to keep
the temporary build directory in case something fails. If the build
succeeds, a symlink <filename>./result</filename> to the package in the
Nix store is created.
</para>
</listitem>
<listitem>
<para>Optionally commit the new package and open a pull request, or send a patch to
<literal>https://groups.google.com/forum/#!forum/nix-devel</literal>.</para>
</listitem>
</orderedlist>
</para>
</listitem>
<listitem>
<para>
If you want to install the package into your profile (optional), do
<screen>
$ nix-env -f . -iA libfoo</screen>
</para>
</listitem>
<listitem>
<para>
Optionally commit the new package and open a pull request, or send a patch
to <literal>https://groups.google.com/forum/#!forum/nix-devel</literal>.
</para>
</listitem>
</orderedlist>
</para>
</chapter>

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715
doc/reviewing-contributions.xml
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@ -3,95 +3,148 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-reviewing-contributions">
<title>Reviewing contributions</title>
<warning>
<para>The following section is a draft and reviewing policy is still being
discussed.</para>
</warning>
<para>The nixpkgs projects receives a fairly high number of contributions via
GitHub pull-requests. Reviewing and approving these is an important task and a
way to contribute to the project.</para>
<para>The high change rate of nixpkgs make any pull request that is open for
long enough subject to conflicts that will require extra work from the
submitter or the merger. Reviewing pull requests in a timely manner and being
<title>Reviewing contributions</title>
<warning>
<para>
The following section is a draft and reviewing policy is still being
discussed.
</para>
</warning>
<para>
The nixpkgs projects receives a fairly high number of contributions via
GitHub pull-requests. Reviewing and approving these is an important task and
a way to contribute to the project.
</para>
<para>
The high change rate of nixpkgs make any pull request that is open for long
enough subject to conflicts that will require extra work from the submitter
or the merger. Reviewing pull requests in a timely manner and being
responsive to the comments is the key to avoid these. GitHub provides sort
filters that can be used to see the <link
filters that can be used to see the
<link
xlink:href="https://github.com/NixOS/nixpkgs/pulls?q=is%3Apr+is%3Aopen+sort%3Aupdated-desc">most
recently</link> and the <link
recently</link> and the
<link
xlink:href="https://github.com/NixOS/nixpkgs/pulls?q=is%3Apr+is%3Aopen+sort%3Aupdated-asc">least
recently</link> updated pull-requests.
We highly encourage looking at <link xlink:href="https://github.com/NixOS/nixpkgs/pulls?q=is%3Apr+is%3Aopen+review%3Anone+status%3Asuccess+-label%3A%222.status%3A+work-in-progress%22+no%3Aproject+no%3Aassignee+no%3Amilestone">
this list of ready to merge, unreviewed pull requests</link>.</para>
<para>When reviewing a pull request, please always be nice and polite.
recently</link> updated pull-requests. We highly encourage looking at
<link xlink:href="https://github.com/NixOS/nixpkgs/pulls?q=is%3Apr+is%3Aopen+review%3Anone+status%3Asuccess+-label%3A%222.status%3A+work-in-progress%22+no%3Aproject+no%3Aassignee+no%3Amilestone">
this list of ready to merge, unreviewed pull requests</link>.
</para>
<para>
When reviewing a pull request, please always be nice and polite.
Controversial changes can lead to controversial opinions, but it is important
to respect every community members and their work.</para>
<para>GitHub provides reactions, they are a simple and quick way to provide
to respect every community members and their work.
</para>
<para>
GitHub provides reactions, they are a simple and quick way to provide
feedback to pull-requests or any comments. The thumb-down reaction should be
used with care and if possible accompanied with some explanations so the
submitter has directions to improve his contribution.</para>
<para>Pull-requests reviews should include a list of what has been reviewed in a
comment, so other reviewers and mergers can know the state of the
review.</para>
<para>All the review template samples provided in this section are generic and
submitter has directions to improve his contribution.
</para>
<para>
Pull-requests reviews should include a list of what has been reviewed in a
comment, so other reviewers and mergers can know the state of the review.
</para>
<para>
All the review template samples provided in this section are generic and
meant as examples. Their usage is optional and the reviewer is free to adapt
them to his liking.</para>
them to his liking.
</para>
<section>
<title>Package updates</title>
<section><title>Package updates</title>
<para>
A package update is the most trivial and common type of pull-request. These
pull-requests mainly consist in updating the version part of the package
name and the source hash.
</para>
<para>A package update is the most trivial and common type of pull-request.
These pull-requests mainly consist in updating the version part of the package
name and the source hash.</para>
<para>It can happen that non trivial updates include patches or more complex
changes.</para>
<para>
It can happen that non trivial updates include patches or more complex
changes.
</para>
<para>Reviewing process:</para>
<para>
Reviewing process:
</para>
<itemizedlist>
<listitem><para>Add labels to the pull-request. (Requires commit
rights)</para>
<itemizedlist>
<listitem>
<para>
Add labels to the pull-request. (Requires commit rights)
</para>
<itemizedlist>
<listitem><para><literal>8.has: package (update)</literal> and any topic
label that fit the updated package.</para></listitem>
<listitem>
<para>
<literal>8.has: package (update)</literal> and any topic label that fit
the updated package.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the package versioning is fitting the
guidelines.</para></listitem>
<listitem><para>Ensure that the commit text is fitting the
guidelines.</para></listitem>
<listitem><para>Ensure that the package maintainers are notified.</para>
</listitem>
<listitem>
<para>
Ensure that the package versioning is fitting the guidelines.
</para>
</listitem>
<listitem>
<para>
Ensure that the commit text is fitting the guidelines.
</para>
</listitem>
<listitem>
<para>
Ensure that the package maintainers are notified.
</para>
<itemizedlist>
<listitem><para>mention-bot usually notify GitHub users based on the
submitted changes, but it can happen that it misses some of the
package maintainers.</para></listitem>
<listitem>
<para>
mention-bot usually notify GitHub users based on the submitted changes,
but it can happen that it misses some of the package maintainers.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the meta field contains correct
information.</para>
</listitem>
<listitem>
<para>
Ensure that the meta field contains correct information.
</para>
<itemizedlist>
<listitem><para>License can change with version updates, so it should be
checked to be fitting upstream license.</para></listitem>
<listitem><para>If the package has no maintainer, a maintainer must be
set. This can be the update submitter or a community member that
accepts to take maintainership of the package.</para></listitem>
<listitem>
<para>
License can change with version updates, so it should be checked to be
fitting upstream license.
</para>
</listitem>
<listitem>
<para>
If the package has no maintainer, a maintainer must be set. This can be
the update submitter or a community member that accepts to take
maintainership of the package.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the code contains no typos.</para></listitem>
<listitem><para>Building the package locally.</para>
</listitem>
<listitem>
<para>
Ensure that the code contains no typos.
</para>
</listitem>
<listitem>
<para>
Building the package locally.
</para>
<itemizedlist>
<listitem><para>Pull-requests are often targeted to the master or staging
branch so building the pull-request locally as it is submitted can
trigger a large amount of source builds.</para>
<para>It is possible to rebase the changes on nixos-unstable or
nixpkgs-unstable for easier review by running the following commands
from a nixpkgs clone.
<listitem>
<para>
Pull-requests are often targeted to the master or staging branch so
building the pull-request locally as it is submitted can trigger a large
amount of source builds.
</para>
<para>
It is possible to rebase the changes on nixos-unstable or
nixpkgs-unstable for easier review by running the following commands
from a nixpkgs clone.
<screen>
$ git remote add channels https://github.com/NixOS/nixpkgs-channels.git <co
xml:id='reviewing-rebase-1' />
@ -100,43 +153,56 @@ $ git fetch origin pull/PRNUMBER/head <co xml:id='reviewing-rebase-3' />
$ git rebase --onto nixos-unstable BASEBRANCH FETCH_HEAD <co
xml:id='reviewing-rebase-4' />
</screen>
<calloutlist>
<callout arearefs='reviewing-rebase-1'>
<para>This should be done only once to be able to fetch channel
branches from the nixpkgs-channels repository.</para>
</callout>
<callout arearefs='reviewing-rebase-2'>
<para>Fetching the nixos-unstable branch.</para>
</callout>
<callout arearefs='reviewing-rebase-3'>
<para>Fetching the pull-request changes, <varname>PRNUMBER</varname>
is the number at the end of the pull-request title and
<varname>BASEBRANCH</varname> the base branch of the
pull-request.</para>
</callout>
<callout arearefs='reviewing-rebase-4'>
<para>Rebasing the pull-request changes to the nixos-unstable
branch.</para>
</callout>
</calloutlist>
</para>
</listitem>
<listitem>
<para>The <link xlink:href="https://github.com/madjar/nox">nox</link>
tool can be used to review a pull-request content in a single command.
It doesn't rebase on a channel branch so it might trigger multiple
source builds. <varname>PRNUMBER</varname> should be replaced by the
number at the end of the pull-request title.</para>
<calloutlist>
<callout arearefs='reviewing-rebase-1'>
<para>
This should be done only once to be able to fetch channel branches
from the nixpkgs-channels repository.
</para>
</callout>
<callout arearefs='reviewing-rebase-2'>
<para>
Fetching the nixos-unstable branch.
</para>
</callout>
<callout arearefs='reviewing-rebase-3'>
<para>
Fetching the pull-request changes, <varname>PRNUMBER</varname> is the
number at the end of the pull-request title and
<varname>BASEBRANCH</varname> the base branch of the pull-request.
</para>
</callout>
<callout arearefs='reviewing-rebase-4'>
<para>
Rebasing the pull-request changes to the nixos-unstable branch.
</para>
</callout>
</calloutlist>
</para>
</listitem>
<listitem>
<para>
The <link xlink:href="https://github.com/madjar/nox">nox</link> tool can
be used to review a pull-request content in a single command. It doesn't
rebase on a channel branch so it might trigger multiple source builds.
<varname>PRNUMBER</varname> should be replaced by the number at the end
of the pull-request title.
</para>
<screen>
$ nix-shell -p nox --run "nox-review -k pr PRNUMBER"
</screen>
</listitem>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Running every binary.</para></listitem>
</itemizedlist>
</listitem>
<listitem>
<para>
Running every binary.
</para>
</listitem>
</itemizedlist>
<example><title>Sample template for a package update review</title>
<example>
<title>Sample template for a package update review</title>
<screen>
##### Reviewed points
@ -150,55 +216,105 @@ $ nix-shell -p nox --run "nox-review -k pr PRNUMBER"
##### Comments
</screen></example>
</section>
</screen>
</example>
</section>
<section>
<title>New packages</title>
<section><title>New packages</title>
<para>
New packages are a common type of pull-requests. These pull requests
consists in adding a new nix-expression for a package.
</para>
<para>New packages are a common type of pull-requests. These pull requests
consists in adding a new nix-expression for a package.</para>
<para>
Reviewing process:
</para>
<para>Reviewing process:</para>
<itemizedlist>
<listitem><para>Add labels to the pull-request. (Requires commit
rights)</para>
<itemizedlist>
<listitem>
<para>
Add labels to the pull-request. (Requires commit rights)
</para>
<itemizedlist>
<listitem><para><literal>8.has: package (new)</literal> and any topic
label that fit the new package.</para></listitem>
<listitem>
<para>
<literal>8.has: package (new)</literal> and any topic label that fit the
new package.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the package versioning is fitting the
guidelines.</para></listitem>
<listitem><para>Ensure that the commit name is fitting the
guidelines.</para></listitem>
<listitem><para>Ensure that the meta field contains correct
information.</para>
</listitem>
<listitem>
<para>
Ensure that the package versioning is fitting the guidelines.
</para>
</listitem>
<listitem>
<para>
Ensure that the commit name is fitting the guidelines.
</para>
</listitem>
<listitem>
<para>
Ensure that the meta field contains correct information.
</para>
<itemizedlist>
<listitem><para>License must be checked to be fitting upstream
license.</para></listitem>
<listitem><para>Platforms should be set or the package will not get binary
substitutes.</para></listitem>
<listitem><para>A maintainer must be set, this can be the package
submitter or a community member that accepts to take maintainership of
the package.</para></listitem>
<listitem>
<para>
License must be checked to be fitting upstream license.
</para>
</listitem>
<listitem>
<para>
Platforms should be set or the package will not get binary substitutes.
</para>
</listitem>
<listitem>
<para>
A maintainer must be set, this can be the package submitter or a
community member that accepts to take maintainership of the package.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the code contains no typos.</para></listitem>
<listitem><para>Ensure the package source.</para>
</listitem>
<listitem>
<para>
Ensure that the code contains no typos.
</para>
</listitem>
<listitem>
<para>
Ensure the package source.
</para>
<itemizedlist>
<listitem><para>Mirrors urls should be used when
available.</para></listitem>
<listitem><para>The most appropriate function should be used (e.g.
packages from GitHub should use
<literal>fetchFromGitHub</literal>).</para></listitem>
<listitem>
<para>
Mirrors urls should be used when available.
</para>
</listitem>
<listitem>
<para>
The most appropriate function should be used (e.g. packages from GitHub
should use <literal>fetchFromGitHub</literal>).
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Building the package locally.</para></listitem>
<listitem><para>Running every binary.</para></listitem>
</itemizedlist>
</listitem>
<listitem>
<para>
Building the package locally.
</para>
</listitem>
<listitem>
<para>
Running every binary.
</para>
</listitem>
</itemizedlist>
<example><title>Sample template for a new package review</title>
<example>
<title>Sample template for a new package review</title>
<screen>
##### Reviewed points
@ -220,58 +336,107 @@ $ nix-shell -p nox --run "nox-review -k pr PRNUMBER"
##### Comments
</screen></example>
</section>
</screen>
</example>
</section>
<section>
<title>Module updates</title>
<section><title>Module updates</title>
<para>
Module updates are submissions changing modules in some ways. These often
contains changes to the options or introduce new options.
</para>
<para>Module updates are submissions changing modules in some ways. These often
contains changes to the options or introduce new options.</para>
<para>
Reviewing process
</para>
<para>Reviewing process</para>
<itemizedlist>
<listitem><para>Add labels to the pull-request. (Requires commit
rights)</para>
<itemizedlist>
<listitem>
<para>
Add labels to the pull-request. (Requires commit rights)
</para>
<itemizedlist>
<listitem><para><literal>8.has: module (update)</literal> and any topic
label that fit the module.</para></listitem>
<listitem>
<para>
<literal>8.has: module (update)</literal> and any topic label that fit
the module.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the module maintainers are notified.</para>
</listitem>
<listitem>
<para>
Ensure that the module maintainers are notified.
</para>
<itemizedlist>
<listitem><para>Mention-bot notify GitHub users based on the submitted
changes, but it can happen that it miss some of the package
maintainers.</para></listitem>
<listitem>
<para>
Mention-bot notify GitHub users based on the submitted changes, but it
can happen that it miss some of the package maintainers.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the module tests, if any, are
succeeding.</para></listitem>
<listitem><para>Ensure that the introduced options are correct.</para>
</listitem>
<listitem>
<para>
Ensure that the module tests, if any, are succeeding.
</para>
</listitem>
<listitem>
<para>
Ensure that the introduced options are correct.
</para>
<itemizedlist>
<listitem><para>Type should be appropriate (string related types differs
in their merging capabilities, <literal>optionSet</literal> and
<literal>string</literal> types are deprecated).</para></listitem>
<listitem><para>Description, default and example should be
provided.</para></listitem>
<listitem>
<para>
Type should be appropriate (string related types differs in their
merging capabilities, <literal>optionSet</literal> and
<literal>string</literal> types are deprecated).
</para>
</listitem>
<listitem>
<para>
Description, default and example should be provided.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that option changes are backward compatible.</para>
</listitem>
<listitem>
<para>
Ensure that option changes are backward compatible.
</para>
<itemizedlist>
<listitem><para><literal>mkRenamedOptionModule</literal> and
<literal>mkAliasOptionModule</literal> functions provide way to make
option changes backward compatible.</para></listitem>
<listitem>
<para>
<literal>mkRenamedOptionModule</literal> and
<literal>mkAliasOptionModule</literal> functions provide way to make
option changes backward compatible.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that removed options are declared with
<literal>mkRemovedOptionModule</literal></para></listitem>
<listitem><para>Ensure that changes that are not backward compatible are
mentioned in release notes.</para></listitem>
<listitem><para>Ensure that documentations affected by the change is
updated.</para></listitem>
</itemizedlist>
</listitem>
<listitem>
<para>
Ensure that removed options are declared with
<literal>mkRemovedOptionModule</literal>
</para>
</listitem>
<listitem>
<para>
Ensure that changes that are not backward compatible are mentioned in
release notes.
</para>
</listitem>
<listitem>
<para>
Ensure that documentations affected by the change is updated.
</para>
</listitem>
</itemizedlist>
<example><title>Sample template for a module update review</title>
<example>
<title>Sample template for a module update review</title>
<screen>
##### Reviewed points
@ -288,51 +453,89 @@ $ nix-shell -p nox --run "nox-review -k pr PRNUMBER"
##### Comments
</screen></example>
</section>
</screen>
</example>
</section>
<section>
<title>New modules</title>
<section><title>New modules</title>
<para>
New modules submissions introduce a new module to NixOS.
</para>
<para>New modules submissions introduce a new module to NixOS.</para>
<itemizedlist>
<listitem>
<para>
Add labels to the pull-request. (Requires commit rights)
</para>
<itemizedlist>
<listitem>
<para>
<literal>8.has: module (new)</literal> and any topic label that fit the
module.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem>
<para>
Ensure that the module tests, if any, are succeeding.
</para>
</listitem>
<listitem>
<para>
Ensure that the introduced options are correct.
</para>
<itemizedlist>
<listitem>
<para>
Type should be appropriate (string related types differs in their
merging capabilities, <literal>optionSet</literal> and
<literal>string</literal> types are deprecated).
</para>
</listitem>
<listitem>
<para>
Description, default and example should be provided.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem>
<para>
Ensure that module <literal>meta</literal> field is present
</para>
<itemizedlist>
<listitem>
<para>
Maintainers should be declared in <literal>meta.maintainers</literal>.
</para>
</listitem>
<listitem>
<para>
Module documentation should be declared with
<literal>meta.doc</literal>.
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem>
<para>
Ensure that the module respect other modules functionality.
</para>
<itemizedlist>
<listitem>
<para>
For example, enabling a module should not open firewall ports by
default.
</para>
</listitem>
</itemizedlist>
</listitem>
</itemizedlist>
<itemizedlist>
<listitem><para>Add labels to the pull-request. (Requires commit
rights)</para>
<itemizedlist>
<listitem><para><literal>8.has: module (new)</literal> and any topic label
that fit the module.</para></listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the module tests, if any, are
succeeding.</para></listitem>
<listitem><para>Ensure that the introduced options are correct.</para>
<itemizedlist>
<listitem><para>Type should be appropriate (string related types differs
in their merging capabilities, <literal>optionSet</literal> and
<literal>string</literal> types are deprecated).</para></listitem>
<listitem><para>Description, default and example should be
provided.</para></listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that module <literal>meta</literal> field is
present</para>
<itemizedlist>
<listitem><para>Maintainers should be declared in
<literal>meta.maintainers</literal>.</para></listitem>
<listitem><para>Module documentation should be declared with
<literal>meta.doc</literal>.</para></listitem>
</itemizedlist>
</listitem>
<listitem><para>Ensure that the module respect other modules
functionality.</para>
<itemizedlist>
<listitem><para>For example, enabling a module should not open firewall
ports by default.</para></listitem>
</itemizedlist>
</listitem>
</itemizedlist>
<example><title>Sample template for a new module review</title>
<example>
<title>Sample template for a new module review</title>
<screen>
##### Reviewed points
@ -350,32 +553,41 @@ $ nix-shell -p nox --run "nox-review -k pr PRNUMBER"
##### Comments
</screen></example>
</section>
</screen>
</example>
</section>
<section>
<title>Other submissions</title>
<section><title>Other submissions</title>
<para>
Other type of submissions requires different reviewing steps.
</para>
<para>Other type of submissions requires different reviewing steps.</para>
<para>
If you consider having enough knowledge and experience in a topic and would
like to be a long-term reviewer for related submissions, please contact the
current reviewers for that topic. They will give you information about the
reviewing process. The main reviewers for a topic can be hard to find as
there is no list, but checking past pull-requests to see who reviewed or
git-blaming the code to see who committed to that topic can give some hints.
</para>
<para>If you consider having enough knowledge and experience in a topic and
would like to be a long-term reviewer for related submissions, please contact
the current reviewers for that topic. They will give you information about the
reviewing process.
The main reviewers for a topic can be hard to find as there is no list, but
checking past pull-requests to see who reviewed or git-blaming the code to see
who committed to that topic can give some hints.</para>
<para>
Container system, boot system and library changes are some examples of the
pull requests fitting this category.
</para>
</section>
<section>
<title>Merging pull-requests</title>
<para>Container system, boot system and library changes are some examples of the
pull requests fitting this category.</para>
<para>
It is possible for community members that have enough knowledge and
experience on a special topic to contribute by merging pull requests.
</para>
</section>
<section><title>Merging pull-requests</title>
<para>It is possible for community members that have enough knowledge and
experience on a special topic to contribute by merging pull requests.</para>
<para>TODO: add the procedure to request merging rights.</para>
<para>
TODO: add the procedure to request merging rights.
</para>
<!--
The following paragraph about how to deal with unactive contributors is just a
@ -386,10 +598,11 @@ policy.
three months will have their commit rights revoked.</para>
-->
<para>In a case a contributor leaves definitively the Nix community, he should
create an issue or notify the mailing list with references of packages and
modules he maintains so the maintainership can be taken over by other
contributors.</para>
</section>
<para>
In a case a contributor leaves definitively the Nix community, he should
create an issue or notify the mailing list with references of packages and
modules he maintains so the maintainership can be taken over by other
contributors.
</para>
</section>
</chapter>

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{ pkgs ? import ../. {} }:
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buildInputs = x.buildInputs ++ [ pkgs.xmloscopy ];
})

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<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xml:id="chap-submitting-changes">
<title>Submitting changes</title>
<section>
<title>Making patches</title>
<title>Submitting changes</title>
<section>
<title>Making patches</title>
<itemizedlist>
<listitem>
<para>Read <link xlink:href="https://nixos.org/nixpkgs/manual/">Manual (How to write packages for Nix)</link>.</para>
</listitem>
<listitem>
<para>Fork the repository on GitHub.</para>
</listitem>
<listitem>
<para>Create a branch for your future fix.
<itemizedlist>
<listitem>
<para>You can make branch from a commit of your local <command>nixos-version</command>. That will help you to avoid additional local compilations. Because you will receive packages from binary cache.
<itemizedlist>
<listitem>
<para>For example: <command>nixos-version</command> returns <command>15.05.git.0998212 (Dingo)</command>. So you can do:</para>
</listitem>
</itemizedlist>
<itemizedlist>
<listitem>
<para>
Read <link xlink:href="https://nixos.org/nixpkgs/manual/">Manual (How to
write packages for Nix)</link>.
</para>
</listitem>
<listitem>
<para>
Fork the repository on GitHub.
</para>
</listitem>
<listitem>
<para>
Create a branch for your future fix.
<itemizedlist>
<listitem>
<para>
You can make branch from a commit of your local
<command>nixos-version</command>. That will help you to avoid
additional local compilations. Because you will receive packages from
binary cache.
<itemizedlist>
<listitem>
<para>
For example: <command>nixos-version</command> returns
<command>15.05.git.0998212 (Dingo)</command>. So you can do:
</para>
</listitem>
</itemizedlist>
<screen>
$ git checkout 0998212
$ git checkout -b 'fix/pkg-name-update'
</screen>
</para>
</listitem>
<listitem>
<para>Please avoid working directly on the <command>master</command> branch.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>Make commits of logical units.
<itemizedlist>
<listitem>
<para>If you removed pkgs, made some major NixOS changes etc., write about them in <command>nixos/doc/manual/release-notes/rl-unstable.xml</command>.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>Check for unnecessary whitespace with <command>git diff --check</command> before committing.</para>
</listitem>
<listitem>
<para>Format the commit in a following way:</para>
</para>
</listitem>
<listitem>
<para>
Please avoid working directly on the <command>master</command> branch.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
Make commits of logical units.
<itemizedlist>
<listitem>
<para>
If you removed pkgs, made some major NixOS changes etc., write about
them in
<command>nixos/doc/manual/release-notes/rl-unstable.xml</command>.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
Check for unnecessary whitespace with <command>git diff --check</command>
before committing.
</para>
</listitem>
<listitem>
<para>
Format the commit in a following way:
</para>
<programlisting>
(pkg-name | nixos/&lt;module>): (from -> to | init at version | refactor | etc)
Additional information.
</programlisting>
<itemizedlist>
<listitem>
<para>
Examples:
<itemizedlist>
<listitem>
<para>
<command>nginx: init at 2.0.1</command>
</para>
</listitem>
<listitem>
<para>
<command>firefox: 54.0.1 -> 55.0</command>
</para>
</listitem>
<listitem>
<para>
<command>nixos/hydra: add bazBaz option</command>
</para>
</listitem>
<listitem>
<para>
<command>nixos/nginx: refactor config generation</command>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem>
<para>
Test your changes. If you work with
<itemizedlist>
<listitem>
<para>
nixpkgs:
<itemizedlist>
<listitem>
<para>
update pkg ->
<itemizedlist>
<listitem>
<para>
<command>nix-env -i pkg-name -f &lt;path to your local nixpkgs
folder&gt;</command>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
add pkg ->
<itemizedlist>
<listitem>
<para>
Make sure it's in
<command>pkgs/top-level/all-packages.nix</command>
</para>
</listitem>
<listitem>
<para>
<command>nix-env -i pkg-name -f &lt;path to your local nixpkgs
folder&gt;</command>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
<emphasis>If you don't want to install pkg in you
profile</emphasis>.
<itemizedlist>
<listitem>
<para>
<command>nix-build -A pkg-attribute-name &lt;path to your local
nixpkgs folder&gt;/default.nix</command> and check results in the
folder <command>result</command>. It will appear in the same
directory where you did <command>nix-build</command>.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
If you did <command>nix-env -i pkg-name</command> you can do
<command>nix-env -e pkg-name</command> to uninstall it from your
system.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
NixOS and its modules:
<itemizedlist>
<listitem>
<para>
You can add new module to your NixOS configuration file (usually
it's <command>/etc/nixos/configuration.nix</command>). And do
<command>sudo nixos-rebuild test -I nixpkgs=&lt;path to your local
nixpkgs folder&gt; --fast</command>.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
If you have commits <command>pkg-name: oh, forgot to insert
whitespace</command>: squash commits in this case. Use <command>git rebase
-i</command>.
</para>
</listitem>
<listitem>
<para>
Rebase you branch against current <command>master</command>.
</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Submitting changes</title>
<itemizedlist>
<listitem>
<para>Examples:
<itemizedlist>
<listitem>
<para>
<command>nginx: init at 2.0.1</command>
</para>
</listitem>
<listitem>
<para>
<command>firefox: 54.0.1 -> 55.0</command>
</para>
</listitem>
<listitem>
<para>
<command>nixos/hydra: add bazBaz option</command>
</para>
</listitem>
<listitem>
<para>
<command>nixos/nginx: refactor config generation</command>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</listitem>
<listitem>
<para>Test your changes. If you work with
<itemizedlist>
<listitem>
<para>nixpkgs:
<itemizedlist>
<listitem>
<para>update pkg ->
<itemizedlist>
<listitem>
<para>
<command>nix-env -i pkg-name -f &lt;path to your local nixpkgs folder&gt;</command>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>add pkg ->
<itemizedlist>
<listitem>
<para>Make sure it's in <command>pkgs/top-level/all-packages.nix</command>
</para>
</listitem>
<listitem>
<para>
<command>nix-env -i pkg-name -f &lt;path to your local nixpkgs folder&gt;</command>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
<emphasis>If you don't want to install pkg in you profile</emphasis>.
<itemizedlist>
<listitem>
<para>
<command>nix-build -A pkg-attribute-name &lt;path to your local nixpkgs folder&gt;/default.nix</command> and check results in the folder <command>result</command>. It will appear in the same directory where you did <command>nix-build</command>.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>If you did <command>nix-env -i pkg-name</command> you can do <command>nix-env -e pkg-name</command> to uninstall it from your system.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>NixOS and its modules:
<itemizedlist>
<listitem>
<para>You can add new module to your NixOS configuration file (usually it's <command>/etc/nixos/configuration.nix</command>).
And do <command>sudo nixos-rebuild test -I nixpkgs=&lt;path to your local nixpkgs folder&gt; --fast</command>.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>If you have commits <command>pkg-name: oh, forgot to insert whitespace</command>: squash commits in this case. Use <command>git rebase -i</command>.</para>
</listitem>
<listitem>
<para>Rebase you branch against current <command>master</command>.</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Submitting changes</title>
<itemizedlist>
<listitem>
<para>Push your changes to your fork of nixpkgs.</para>
</listitem>
<listitem>
<para>Create pull request:
<itemizedlist>
<listitem>
<para>Write the title in format <command>(pkg-name | nixos/&lt;module>): improvement</command>.
<itemizedlist>
<listitem>
<para>If you update the pkg, write versions <command>from -> to</command>.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>Write in comment if you have tested your patch. Do not rely much on <command>TravisCI</command>.</para>
</listitem>
<listitem>
<para>If you make an improvement, write about your motivation.</para>
</listitem>
<listitem>
<para>Notify maintainers of the package. For example add to the message: <command>cc @jagajaga @domenkozar</command>.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</section>
<section>
<itemizedlist>
<listitem>
<para>
Push your changes to your fork of nixpkgs.
</para>
</listitem>
<listitem>
<para>
Create pull request:
<itemizedlist>
<listitem>
<para>
Write the title in format <command>(pkg-name | nixos/&lt;module>):
improvement</command>.
<itemizedlist>
<listitem>
<para>
If you update the pkg, write versions <command>from -> to</command>.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
<listitem>
<para>
Write in comment if you have tested your patch. Do not rely much on
<command>TravisCI</command>.
</para>
</listitem>
<listitem>
<para>
If you make an improvement, write about your motivation.
</para>
</listitem>
<listitem>
<para>
Notify maintainers of the package. For example add to the message:
<command>cc @jagajaga @domenkozar</command>.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Pull Request Template</title>
<para>
The pull request template helps determine what steps have been made for a
contribution so far, and will help guide maintainers on the status of a
change. The motivation section of the PR should include any extra details
the title does not address and link any existing issues related to the pull
request.
The pull request template helps determine what steps have been made for a
contribution so far, and will help guide maintainers on the status of a
change. The motivation section of the PR should include any extra details
the title does not address and link any existing issues related to the pull
request.
</para>
<para>When a PR is created, it will be pre-populated with some checkboxes detailed below:
<para>
When a PR is created, it will be pre-populated with some checkboxes detailed
below:
</para>
<section>
<title>Tested using sandboxing</title>
<para>
When sandbox builds are enabled, Nix will setup an isolated environment
for each build process. It is used to remove further hidden dependencies
set by the build environment to improve reproducibility. This includes
access to the network during the build outside of
<function>fetch*</function> functions and files outside the Nix store.
Depending on the operating system access to other resources are blocked
as well (ex. inter process communication is isolated on Linux); see <link
<title>Tested using sandboxing</title>
<para>
When sandbox builds are enabled, Nix will setup an isolated environment for
each build process. It is used to remove further hidden dependencies set by
the build environment to improve reproducibility. This includes access to
the network during the build outside of <function>fetch*</function>
functions and files outside the Nix store. Depending on the operating
system access to other resources are blocked as well (ex. inter process
communication is isolated on Linux); see
<link
xlink:href="https://nixos.org/nix/manual/#description-45">build-use-sandbox</link>
in Nix manual for details.
</para>
<para>
Sandboxing is not enabled by default in Nix due to a small performance
hit on each build. In pull requests for <link
xlink:href="https://github.com/NixOS/nixpkgs/">nixpkgs</link> people
are asked to test builds with sandboxing enabled (see <literal>Tested
using sandboxing</literal> in the pull request template) because
in<link
in Nix manual for details.
</para>
<para>
Sandboxing is not enabled by default in Nix due to a small performance hit
on each build. In pull requests for
<link
xlink:href="https://github.com/NixOS/nixpkgs/">nixpkgs</link>
people are asked to test builds with sandboxing enabled (see
<literal>Tested using sandboxing</literal> in the pull request template)
because
in<link
xlink:href="https://nixos.org/hydra/">https://nixos.org/hydra/</link>
sandboxing is also used.
</para>
<para>
Depending if you use NixOS or other platforms you can use one of the
following methods to enable sandboxing <emphasis role="bold">before</emphasis> building the package:
<itemizedlist>
<listitem>
<para>
<emphasis role="bold">Globally enable sandboxing on NixOS</emphasis>:
add the following to
<filename>configuration.nix</filename>
<screen>nix.useSandbox = true;</screen>
</para>
</listitem>
<listitem>
<para>
<emphasis role="bold">Globally enable sandboxing on non-NixOS platforms</emphasis>:
add the following to: <filename>/etc/nix/nix.conf</filename>
<screen>build-use-sandbox = true</screen>
</para>
</listitem>
</itemizedlist>
</para>
sandboxing is also used.
</para>
<para>
Depending if you use NixOS or other platforms you can use one of the
following methods to enable sandboxing
<emphasis role="bold">before</emphasis> building the package:
<itemizedlist>
<listitem>
<para>
<emphasis role="bold">Globally enable sandboxing on NixOS</emphasis>:
add the following to <filename>configuration.nix</filename>
<screen>nix.useSandbox = true;</screen>
</para>
</listitem>
<listitem>
<para>
<emphasis role="bold">Globally enable sandboxing on non-NixOS
platforms</emphasis>: add the following to:
<filename>/etc/nix/nix.conf</filename>
<screen>build-use-sandbox = true</screen>
</para>
</listitem>
</itemizedlist>
</para>
</section>
<section>
<title>Built on platform(s)</title>
<para>
Many Nix packages are designed to run on multiple
platforms. As such, it's important to let the maintainer know which
platforms your changes have been tested on. It's not always practical to
test a change on all platforms, and is not required for a pull request to
be merged. Only check the systems you tested the build on in this
section.
</para>
<title>Built on platform(s)</title>
<para>
Many Nix packages are designed to run on multiple platforms. As such, it's
important to let the maintainer know which platforms your changes have been
tested on. It's not always practical to test a change on all platforms, and
is not required for a pull request to be merged. Only check the systems you
tested the build on in this section.
</para>
</section>
<section>
<title>Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)</title>
<para>
Packages with automated tests are much more likely to be merged in a
timely fashion because it doesn't require as much manual testing by the
maintainer to verify the functionality of the package. If there are
existing tests for the package, they should be run to verify your changes
do not break the tests. Tests only apply to packages with NixOS modules
defined and can only be run on Linux. For more details on writing and
running tests, see the <link
<title>Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)</title>
<para>
Packages with automated tests are much more likely to be merged in a timely
fashion because it doesn't require as much manual testing by the maintainer
to verify the functionality of the package. If there are existing tests for
the package, they should be run to verify your changes do not break the
tests. Tests only apply to packages with NixOS modules defined and can only
be run on Linux. For more details on writing and running tests, see the
<link
xlink:href="https://nixos.org/nixos/manual/index.html#sec-nixos-tests">section
in the NixOS manual</link>.
</para>
in the NixOS manual</link>.
</para>
</section>
<section>
<title>Tested compilation of all pkgs that depend on this change using <command>nox-review</command></title>
<para>
If you are updating a package's version, you can use nox to make sure all
packages that depend on the updated package still compile correctly. This
can be done using the nox utility. The <command>nox-review</command>
utility can look for and build all dependencies either based on
uncommited changes with the <literal>wip</literal> option or specifying a
github pull request number.
</para>
<para>
review uncommitted changes:
<screen>nix-shell -p nox --run "nox-review wip"</screen>
</para>
<para>
review changes from pull request number 12345:
<screen>nix-shell -p nox --run "nox-review pr 12345"</screen>
</para>
<title>Tested compilation of all pkgs that depend on this change using <command>nox-review</command></title>
<para>
If you are updating a package's version, you can use nox to make sure all
packages that depend on the updated package still compile correctly. This
can be done using the nox utility. The <command>nox-review</command>
utility can look for and build all dependencies either based on uncommited
changes with the <literal>wip</literal> option or specifying a github pull
request number.
</para>
<para>
review uncommitted changes:
<screen>nix-shell -p nox --run "nox-review wip"</screen>
</para>
<para>
review changes from pull request number 12345:
<screen>nix-shell -p nox --run "nox-review pr 12345"</screen>
</para>
</section>
<section>
<title>Tested execution of all binary files (usually in <filename>./result/bin/</filename>)</title>
<para>
It's important to test any executables generated by a build when you
change or create a package in nixpkgs. This can be done by looking in
<filename>./result/bin</filename> and running any files in there, or at a
minimum, the main executable for the package. For example, if you make a change
to <package>texlive</package>, you probably would only check the binaries
associated with the change you made rather than testing all of them.
</para>
<title>Tested execution of all binary files (usually in <filename>./result/bin/</filename>)</title>
<para>
It's important to test any executables generated by a build when you change
or create a package in nixpkgs. This can be done by looking in
<filename>./result/bin</filename> and running any files in there, or at a
minimum, the main executable for the package. For example, if you make a
change to <package>texlive</package>, you probably would only check the
binaries associated with the change you made rather than testing all of
them.
</para>
</section>
<section>
<title>Meets nixpkgs contribution standards</title>
<para>
The last checkbox is fits <link
<title>Meets nixpkgs contribution standards</title>
<para>
The last checkbox is fits
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/.github/CONTRIBUTING.md">CONTRIBUTING.md</link>.
The contributing document has detailed information on standards the Nix
community has for commit messages, reviews, licensing of contributions
you make to the project, etc... Everyone should read and understand the
standards the community has for contributing before submitting a pull
request.
</para>
The contributing document has detailed information on standards the Nix
community has for commit messages, reviews, licensing of contributions you
make to the project, etc... Everyone should read and understand the
standards the community has for contributing before submitting a pull
request.
</para>
</section>
</section>
<section>
<title>Hotfixing pull requests</title>
<itemizedlist>
<listitem>
<para>Make the appropriate changes in you branch.</para>
</listitem>
<listitem>
<para>Don't create additional commits, do
<itemizedlist>
<listitem>
<para><command>git rebase -i</command></para>
</listitem>
<listitem>
<para>
<command>git push --force</command> to your branch.</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Commit policy</title>
<itemizedlist>
<listitem>
<para>Commits must be sufficiently tested before being merged, both for the master and staging branches.</para>
</listitem>
<listitem>
<para>Hydra builds for master and staging should not be used as testing platform, it's a build farm for changes that have been already tested.</para>
</listitem>
<listitem>
<para>When changing the bootloader installation process, extra care must be taken. Grub installations cannot be rolled back, hence changes may break people's installations forever. For any non-trivial change to the bootloader please file a PR asking for review, especially from @edolstra.</para>
</listitem>
</itemizedlist>
<section>
<title>Master branch</title>
</section>
<section>
<title>Hotfixing pull requests</title>
<itemizedlist>
<listitem>
<para>
It should only see non-breaking commits that do not cause mass rebuilds.
</para>
</listitem>
<listitem>
<para>
Make the appropriate changes in you branch.
</para>
</listitem>
<listitem>
<para>
Don't create additional commits, do
<itemizedlist>
<listitem>
<para>
<command>git rebase -i</command>
</para>
</listitem>
<listitem>
<para>
<command>git push --force</command> to your branch.
</para>
</listitem>
</itemizedlist>
</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Staging branch</title>
</section>
<section>
<title>Commit policy</title>
<itemizedlist>
<listitem>
<para>
It's only for non-breaking mass-rebuild commits. That means it's not to
be used for testing, and changes must have been well tested already.
<link xlink:href="http://comments.gmane.org/gmane.linux.distributions.nixos/13447">Read policy here</link>.
</para>
</listitem>
<listitem>
<para>
If the branch is already in a broken state, please refrain from adding
extra new breakages. Stabilize it for a few days, merge into master,
then resume development on staging.
<link xlink:href="http://hydra.nixos.org/jobset/nixpkgs/staging#tabs-evaluations">Keep an eye on the staging evaluations here</link>.
If any fixes for staging happen to be already in master, then master can
be merged into staging.
</para>
</listitem>
<listitem>
<para>
Commits must be sufficiently tested before being merged, both for the
master and staging branches.
</para>
</listitem>
<listitem>
<para>
Hydra builds for master and staging should not be used as testing
platform, it's a build farm for changes that have been already tested.
</para>
</listitem>
<listitem>
<para>
When changing the bootloader installation process, extra care must be
taken. Grub installations cannot be rolled back, hence changes may break
people's installations forever. For any non-trivial change to the
bootloader please file a PR asking for review, especially from @edolstra.
</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Stable release branches</title>
<section>
<title>Master branch</title>
<itemizedlist>
<itemizedlist>
<listitem>
<para>
If you're cherry-picking a commit to a stable release branch, always use
<command>git cherry-pick -xe</command> and ensure the message contains a
clear description about why this needs to be included in the stable
branch.
</para>
<para>An example of a cherry-picked commit would look like this:</para>
<screen>
<para>
It should only see non-breaking commits that do not cause mass rebuilds.
</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Staging branch</title>
<itemizedlist>
<listitem>
<para>
It's only for non-breaking mass-rebuild commits. That means it's not to
be used for testing, and changes must have been well tested already.
<link xlink:href="http://comments.gmane.org/gmane.linux.distributions.nixos/13447">Read
policy here</link>.
</para>
</listitem>
<listitem>
<para>
If the branch is already in a broken state, please refrain from adding
extra new breakages. Stabilize it for a few days, merge into master, then
resume development on staging.
<link xlink:href="http://hydra.nixos.org/jobset/nixpkgs/staging#tabs-evaluations">Keep
an eye on the staging evaluations here</link>. If any fixes for staging
happen to be already in master, then master can be merged into staging.
</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Stable release branches</title>
<itemizedlist>
<listitem>
<para>
If you're cherry-picking a commit to a stable release branch, always use
<command>git cherry-pick -xe</command> and ensure the message contains a
clear description about why this needs to be included in the stable
branch.
</para>
<para>
An example of a cherry-picked commit would look like this:
</para>
<screen>
nixos: Refactor the world.
The original commit message describing the reason why the world was torn apart.
@ -451,9 +517,7 @@ Reason: I just had a gut feeling that this would also be wanted by people from
the stone age.
</screen>
</listitem>
</itemizedlist>
</section>
</section>
</itemizedlist>
</section>
</section>
</chapter>

2
lib/systems/examples.nix
View File

@ -96,7 +96,7 @@ rec {
};
iphone32 = {
config = "armv7-apple-ios";
config = "armv7a-apple-ios";
# config = "arm-apple-darwin10";
sdkVer = "10.2";
useiOSPrebuilt = true;

5
maintainers/maintainer-list.nix
View File

@ -3984,6 +3984,11 @@
github = "vyp";
name = "vyp";
};
wchresta = {
email = "wchresta.nix@chrummibei.ch";
github = "wchresta";
name = "wchresta";
};
wedens = {
email = "kirill.wedens@gmail.com";
name = "wedens";

2
nixos/doc/manual/.gitignore vendored Normal file
View File

@ -0,0 +1,2 @@
generated
manual-combined.xml

20
nixos/doc/manual/Makefile
View File

@ -1,6 +1,22 @@
debug:
.PHONY: all
all: manual-combined.xml format
.PHONY: debug
debug: generated manual-combined.xml
manual-combined.xml: generated *.xml
rm -f ./manual-combined.xml
nix-shell --packages xmloscopy \
--run 'xmloscopy --docbook5 ./manual.xml ./manual-combined.xml'
--run "xmloscopy --docbook5 ./manual.xml ./manual-combined.xml"
.PHONY: format
format:
find . -iname '*.xml' -type f -print0 | xargs -0 -I{} -n1 \
xmlformat --config-file "../xmlformat.conf" -i {}
.PHONY: clean
clean:
rm -f manual-combined.xml generated
generated: ./options-to-docbook.xsl
nix-build ../../release.nix \

134
nixos/doc/manual/administration/boot-problems.xml
View File

@ -3,63 +3,83 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-boot-problems">
<title>Boot Problems</title>
<title>Boot Problems</title>
<para>If NixOS fails to boot, there are a number of kernel command
line parameters that may help you to identify or fix the issue. You
can add these parameters in the GRUB boot menu by pressing “e” to
modify the selected boot entry and editing the line starting with
<literal>linux</literal>. The following are some useful kernel command
line parameters that are recognised by the NixOS boot scripts or by
systemd:
<variablelist>
<varlistentry><term><literal>boot.shell_on_fail</literal></term>
<listitem><para>Start a root shell if something goes wrong in
stage 1 of the boot process (the initial ramdisk). This is
disabled by default because there is no authentication for the
root shell.</para></listitem>
</varlistentry>
<varlistentry><term><literal>boot.debug1</literal></term>
<listitem><para>Start an interactive shell in stage 1 before
anything useful has been done. That is, no modules have been
loaded and no file systems have been mounted, except for
<filename>/proc</filename> and
<filename>/sys</filename>.</para></listitem>
</varlistentry>
<varlistentry><term><literal>boot.trace</literal></term>
<listitem><para>Print every shell command executed by the stage 1
and 2 boot scripts.</para></listitem>
</varlistentry>
<varlistentry><term><literal>single</literal></term>
<listitem><para>Boot into rescue mode (a.k.a. single user mode).
This will cause systemd to start nothing but the unit
<literal>rescue.target</literal>, which runs
<command>sulogin</command> to prompt for the root password and
start a root login shell. Exiting the shell causes the system to
continue with the normal boot process.</para></listitem>
</varlistentry>
<varlistentry><term><literal>systemd.log_level=debug systemd.log_target=console</literal></term>
<listitem><para>Make systemd very verbose and send log messages to
the console instead of the journal.</para></listitem>
</varlistentry>
</variablelist>
For more parameters recognised by systemd, see
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
<para>If no login prompts or X11 login screens appear (e.g. due to
hanging dependencies), you can press Alt+ArrowUp. If you’re lucky,
this will start rescue mode (described above). (Also note that since
most units have a 90-second timeout before systemd gives up on them,
the <command>agetty</command> login prompts should appear eventually
unless something is very wrong.)</para>
<para>
If NixOS fails to boot, there are a number of kernel command line parameters
that may help you to identify or fix the issue. You can add these parameters
in the GRUB boot menu by pressing “e” to modify the selected boot entry
and editing the line starting with <literal>linux</literal>. The following
are some useful kernel command line parameters that are recognised by the
NixOS boot scripts or by systemd:
<variablelist>
<varlistentry>
<term><literal>boot.shell_on_fail</literal>
</term>
<listitem>
<para>
Start a root shell if something goes wrong in stage 1 of the boot process
(the initial ramdisk). This is disabled by default because there is no
authentication for the root shell.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>boot.debug1</literal>
</term>
<listitem>
<para>
Start an interactive shell in stage 1 before anything useful has been
done. That is, no modules have been loaded and no file systems have been
mounted, except for <filename>/proc</filename> and
<filename>/sys</filename>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>boot.trace</literal>
</term>
<listitem>
<para>
Print every shell command executed by the stage 1 and 2 boot scripts.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>single</literal>
</term>
<listitem>
<para>
Boot into rescue mode (a.k.a. single user mode). This will cause systemd
to start nothing but the unit <literal>rescue.target</literal>, which
runs <command>sulogin</command> to prompt for the root password and start
a root login shell. Exiting the shell causes the system to continue with
the normal boot process.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>systemd.log_level=debug systemd.log_target=console</literal>
</term>
<listitem>
<para>
Make systemd very verbose and send log messages to the console instead of
the journal.
</para>
</listitem>
</varlistentry>
</variablelist>
For more parameters recognised by systemd, see <citerefentry>
<refentrytitle>systemd</refentrytitle>
<manvolnum>1</manvolnum></citerefentry>.
</para>
<para>
If no login prompts or X11 login screens appear (e.g. due to hanging
dependencies), you can press Alt+ArrowUp. If you’re lucky, this will start
rescue mode (described above). (Also note that since most units have a
90-second timeout before systemd gives up on them, the
<command>agetty</command> login prompts should appear eventually unless
something is very wrong.)
</para>
</section>

65
nixos/doc/manual/administration/cleaning-store.xml
View File

@ -3,60 +3,51 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-nix-gc">
<title>Cleaning the Nix Store</title>
<para>Nix has a purely functional model, meaning that packages are
never upgraded in place. Instead new versions of packages end up in a
different location in the Nix store (<filename>/nix/store</filename>).
You should periodically run Nix’s <emphasis>garbage
collector</emphasis> to remove old, unreferenced packages. This is
easy:
<title>Cleaning the Nix Store</title>
<para>
Nix has a purely functional model, meaning that packages are never upgraded
in place. Instead new versions of packages end up in a different location in
the Nix store (<filename>/nix/store</filename>). You should periodically run
Nix’s <emphasis>garbage collector</emphasis> to remove old, unreferenced
packages. This is easy:
<screen>
$ nix-collect-garbage
</screen>
Alternatively, you can use a systemd unit that does the same in the
background:
Alternatively, you can use a systemd unit that does the same in the
background:
<screen>
# systemctl start nix-gc.service
</screen>
You can tell NixOS in <filename>configuration.nix</filename> to run
this unit automatically at certain points in time, for instance, every
night at 03:15:
You can tell NixOS in <filename>configuration.nix</filename> to run this unit
automatically at certain points in time, for instance, every night at 03:15:
<programlisting>
<xref linkend="opt-nix.gc.automatic"/> = true;
<xref linkend="opt-nix.gc.dates"/> = "03:15";
</programlisting>
</para>
<para>The commands above do not remove garbage collector roots, such
as old system configurations. Thus they do not remove the ability to
roll back to previous configurations. The following command deletes
old roots, removing the ability to roll back to them:
</para>
<para>
The commands above do not remove garbage collector roots, such as old system
configurations. Thus they do not remove the ability to roll back to previous
configurations. The following command deletes old roots, removing the ability
to roll back to them:
<screen>
$ nix-collect-garbage -d
</screen>
You can also do this for specific profiles, e.g.
You can also do this for specific profiles, e.g.
<screen>
$ nix-env -p /nix/var/nix/profiles/per-user/eelco/profile --delete-generations old
</screen>
Note that NixOS system configurations are stored in the profile
<filename>/nix/var/nix/profiles/system</filename>.</para>
<para>Another way to reclaim disk space (often as much as 40% of the
size of the Nix store) is to run Nix’s store optimiser, which seeks
out identical files in the store and replaces them with hard links to
a single copy.
Note that NixOS system configurations are stored in the profile
<filename>/nix/var/nix/profiles/system</filename>.
</para>
<para>
Another way to reclaim disk space (often as much as 40% of the size of the
Nix store) is to run Nix’s store optimiser, which seeks out identical files
in the store and replaces them with hard links to a single copy.
<screen>
$ nix-store --optimise
</screen>
Since this command needs to read the entire Nix store, it can take
quite a while to finish.</para>
Since this command needs to read the entire Nix store, it can take quite a
while to finish.
</para>
</chapter>

63
nixos/doc/manual/administration/container-networking.xml
View File

@ -3,15 +3,13 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-container-networking">
<title>Container Networking</title>
<title>Container Networking</title>
<para>When you create a container using <literal>nixos-container
create</literal>, it gets it own private IPv4 address in the range
<literal>10.233.0.0/16</literal>. You can get the container’s IPv4
address as follows:
<para>
When you create a container using <literal>nixos-container create</literal>,
it gets it own private IPv4 address in the range
<literal>10.233.0.0/16</literal>. You can get the container’s IPv4 address
as follows:
<screen>
# nixos-container show-ip foo
10.233.4.2
@ -19,40 +17,39 @@ address as follows:
$ ping -c1 10.233.4.2
64 bytes from 10.233.4.2: icmp_seq=1 ttl=64 time=0.106 ms
</screen>
</para>
</para>
<para>Networking is implemented using a pair of virtual Ethernet
devices. The network interface in the container is called
<literal>eth0</literal>, while the matching interface in the host is
called <literal>ve-<replaceable>container-name</replaceable></literal>
(e.g., <literal>ve-foo</literal>). The container has its own network
namespace and the <literal>CAP_NET_ADMIN</literal> capability, so it
can perform arbitrary network configuration such as setting up
firewall rules, without affecting or having access to the host’s
network.</para>
<para>By default, containers cannot talk to the outside network. If
you want that, you should set up Network Address Translation (NAT)
rules on the host to rewrite container traffic to use your external
IP address. This can be accomplished using the following configuration
on the host:
<para>
Networking is implemented using a pair of virtual Ethernet devices. The
network interface in the container is called <literal>eth0</literal>, while
the matching interface in the host is called
<literal>ve-<replaceable>container-name</replaceable></literal> (e.g.,
<literal>ve-foo</literal>). The container has its own network namespace and
the <literal>CAP_NET_ADMIN</literal> capability, so it can perform arbitrary
network configuration such as setting up firewall rules, without affecting or
having access to the host’s network.
</para>
<para>
By default, containers cannot talk to the outside network. If you want that,
you should set up Network Address Translation (NAT) rules on the host to
rewrite container traffic to use your external IP address. This can be
accomplished using the following configuration on the host:
<programlisting>
<xref linkend="opt-networking.nat.enable"/> = true;
<xref linkend="opt-networking.nat.internalInterfaces"/> = ["ve-+"];
<xref linkend="opt-networking.nat.externalInterface"/> = "eth0";
</programlisting>
where <literal>eth0</literal> should be replaced with the desired
external interface. Note that <literal>ve-+</literal> is a wildcard
that matches all container interfaces.</para>
<para>If you are using Network Manager, you need to explicitly prevent
it from managing container interfaces:
where <literal>eth0</literal> should be replaced with the desired external
interface. Note that <literal>ve-+</literal> is a wildcard that matches all
container interfaces.
</para>
<para>
If you are using Network Manager, you need to explicitly prevent it from
managing container interfaces:
<programlisting>
networking.networkmanager.unmanaged = [ "interface-name:ve-*" ];
</programlisting>
</para>
</para>
</section>

56
nixos/doc/manual/administration/containers.xml
View File

@ -3,32 +3,32 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="ch-containers">
<title>Container Management</title>
<para>NixOS allows you to easily run other NixOS instances as
<emphasis>containers</emphasis>. Containers are a light-weight
approach to virtualisation that runs software in the container at the
same speed as in the host system. NixOS containers share the Nix store
of the host, making container creation very efficient.</para>
<warning><para>Currently, NixOS containers are not perfectly isolated
from the host system. This means that a user with root access to the
container can do things that affect the host. So you should not give
container root access to untrusted users.</para></warning>
<para>NixOS containers can be created in two ways: imperatively, using
the command <command>nixos-container</command>, and declaratively, by
specifying them in your <filename>configuration.nix</filename>. The
declarative approach implies that containers get upgraded along with
your host system when you run <command>nixos-rebuild</command>, which
is often not what you want. By contrast, in the imperative approach,
containers are configured and updated independently from the host
system.</para>
<xi:include href="imperative-containers.xml" />
<xi:include href="declarative-containers.xml" />
<xi:include href="container-networking.xml" />
<title>Container Management</title>
<para>
NixOS allows you to easily run other NixOS instances as
<emphasis>containers</emphasis>. Containers are a light-weight approach to
virtualisation that runs software in the container at the same speed as in
the host system. NixOS containers share the Nix store of the host, making
container creation very efficient.
</para>
<warning>
<para>
Currently, NixOS containers are not perfectly isolated from the host system.
This means that a user with root access to the container can do things that
affect the host. So you should not give container root access to untrusted
users.
</para>
</warning>
<para>
NixOS containers can be created in two ways: imperatively, using the command
<command>nixos-container</command>, and declaratively, by specifying them in
your <filename>configuration.nix</filename>. The declarative approach implies
that containers get upgraded along with your host system when you run
<command>nixos-rebuild</command>, which is often not what you want. By
contrast, in the imperative approach, containers are configured and updated
independently from the host system.
</para>
<xi:include href="imperative-containers.xml" />
<xi:include href="declarative-containers.xml" />
<xi:include href="container-networking.xml" />
</chapter>

80
nixos/doc/manual/administration/control-groups.xml
View File

@ -3,20 +3,18 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-cgroups">
<title>Control Groups</title>
<para>To keep track of the processes in a running system, systemd uses
<emphasis>control groups</emphasis> (cgroups). A control group is a
set of processes used to allocate resources such as CPU, memory or I/O
bandwidth. There can be multiple control group hierarchies, allowing
each kind of resource to be managed independently.</para>
<para>The command <command>systemd-cgls</command> lists all control
groups in the <literal>systemd</literal> hierarchy, which is what
systemd uses to keep track of the processes belonging to each service
or user session:
<title>Control Groups</title>
<para>
To keep track of the processes in a running system, systemd uses
<emphasis>control groups</emphasis> (cgroups). A control group is a set of
processes used to allocate resources such as CPU, memory or I/O bandwidth.
There can be multiple control group hierarchies, allowing each kind of
resource to be managed independently.
</para>
<para>
The command <command>systemd-cgls</command> lists all control groups in the
<literal>systemd</literal> hierarchy, which is what systemd uses to keep
track of the processes belonging to each service or user session:
<screen>
$ systemd-cgls
├─user
@ -34,40 +32,34 @@ $ systemd-cgls
│ └─2376 dhcpcd --config /nix/store/f8dif8dsi2yaa70n03xir8r653776ka6-dhcpcd.conf
└─ <replaceable>...</replaceable>
</screen>
Similarly, <command>systemd-cgls cpu</command> shows the cgroups in
the CPU hierarchy, which allows per-cgroup CPU scheduling priorities.
By default, every systemd service gets its own CPU cgroup, while all
user sessions are in the top-level CPU cgroup. This ensures, for
instance, that a thousand run-away processes in the
<literal>httpd.service</literal> cgroup cannot starve the CPU for one
process in the <literal>postgresql.service</literal> cgroup. (By
contrast, it they were in the same cgroup, then the PostgreSQL process
would get 1/1001 of the cgroup’s CPU time.) You can limit a service’s
CPU share in <filename>configuration.nix</filename>:
Similarly, <command>systemd-cgls cpu</command> shows the cgroups in the CPU
hierarchy, which allows per-cgroup CPU scheduling priorities. By default,
every systemd service gets its own CPU cgroup, while all user sessions are in
the top-level CPU cgroup. This ensures, for instance, that a thousand
run-away processes in the <literal>httpd.service</literal> cgroup cannot
starve the CPU for one process in the <literal>postgresql.service</literal>
cgroup. (By contrast, it they were in the same cgroup, then the PostgreSQL
process would get 1/1001 of the cgroup’s CPU time.) You can limit a
service’s CPU share in <filename>configuration.nix</filename>:
<programlisting>
<link linkend="opt-systemd.services._name_.serviceConfig">systemd.services.httpd.serviceConfig</link>.CPUShares = 512;
</programlisting>
By default, every cgroup has 1024 CPU shares, so this will halve the
CPU allocation of the <literal>httpd.service</literal> cgroup.</para>
<para>There also is a <literal>memory</literal> hierarchy that
controls memory allocation limits; by default, all processes are in
the top-level cgroup, so any service or session can exhaust all
available memory. Per-cgroup memory limits can be specified in
<filename>configuration.nix</filename>; for instance, to limit
<literal>httpd.service</literal> to 512 MiB of RAM (excluding swap):
By default, every cgroup has 1024 CPU shares, so this will halve the CPU
allocation of the <literal>httpd.service</literal> cgroup.
</para>
<para>
There also is a <literal>memory</literal> hierarchy that controls memory
allocation limits; by default, all processes are in the top-level cgroup, so
any service or session can exhaust all available memory. Per-cgroup memory
limits can be specified in <filename>configuration.nix</filename>; for
instance, to limit <literal>httpd.service</literal> to 512 MiB of RAM
(excluding swap):
<programlisting>
<link linkend="opt-systemd.services._name_.serviceConfig">systemd.services.httpd.serviceConfig</link>.MemoryLimit = "512M";
</programlisting>
</para>
<para>The command <command>systemd-cgtop</command> shows a
continuously updated list of all cgroups with their CPU and memory
usage.</para>
</para>
<para>
The command <command>systemd-cgtop</command> shows a continuously updated
list of all cgroups with their CPU and memory usage.
</para>
</chapter>

68
nixos/doc/manual/administration/declarative-containers.xml
View File

@ -3,14 +3,13 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-declarative-containers">
<title>Declarative Container Specification</title>
<title>Declarative Container Specification</title>
<para>You can also specify containers and their configuration in the
host’s <filename>configuration.nix</filename>. For example, the
following specifies that there shall be a container named
<literal>database</literal> running PostgreSQL:
<para>
You can also specify containers and their configuration in the host’s
<filename>configuration.nix</filename>. For example, the following specifies
that there shall be a container named <literal>database</literal> running
PostgreSQL:
<programlisting>
containers.database =
{ config =
@ -20,18 +19,18 @@ containers.database =
};
};
</programlisting>
If you run <literal>nixos-rebuild switch</literal>, the container will be
built. If the container was already running, it will be updated in place,
without rebooting. The container can be configured to start automatically by
setting <literal>containers.database.autoStart = true</literal> in its
configuration.
</para>
If you run <literal>nixos-rebuild switch</literal>, the container will
be built. If the container was already running, it will be
updated in place, without rebooting. The container can be configured to
start automatically by setting <literal>containers.database.autoStart = true</literal>
in its configuration.</para>
<para>By default, declarative containers share the network namespace
of the host, meaning that they can listen on (privileged)
ports. However, they cannot change the network configuration. You can
give a container its own network as follows:
<para>
By default, declarative containers share the network namespace of the host,
meaning that they can listen on (privileged) ports. However, they cannot
change the network configuration. You can give a container its own network as
follows:
<programlisting>
containers.database = {
<link linkend="opt-containers._name_.privateNetwork">privateNetwork</link> = true;
@ -39,22 +38,23 @@ containers.database = {
<link linkend="opt-containers._name_.localAddress">localAddress</link> = "192.168.100.11";
};
</programlisting>
This gives the container a private virtual Ethernet interface with IP address
<literal>192.168.100.11</literal>, which is hooked up to a virtual Ethernet
interface on the host with IP address <literal>192.168.100.10</literal>. (See
the next section for details on container networking.)
</para>
This gives the container a private virtual Ethernet interface with IP
address <literal>192.168.100.11</literal>, which is hooked up to a
virtual Ethernet interface on the host with IP address
<literal>192.168.100.10</literal>. (See the next section for details
on container networking.)</para>
<para>To disable the container, just remove it from
<filename>configuration.nix</filename> and run <literal>nixos-rebuild
switch</literal>. Note that this will not delete the root directory of
the container in <literal>/var/lib/containers</literal>. Containers can be
destroyed using the imperative method: <literal>nixos-container destroy
foo</literal>.</para>
<para>Declarative containers can be started and stopped using the
corresponding systemd service, e.g. <literal>systemctl start
container@database</literal>.</para>
<para>
To disable the container, just remove it from
<filename>configuration.nix</filename> and run <literal>nixos-rebuild
switch</literal>. Note that this will not delete the root directory of the
container in <literal>/var/lib/containers</literal>. Containers can be
destroyed using the imperative method: <literal>nixos-container destroy
foo</literal>.
</para>
<para>
Declarative containers can be started and stopped using the corresponding
systemd service, e.g. <literal>systemctl start container@database</literal>.
</para>
</section>

135
nixos/doc/manual/administration/imperative-containers.xml
View File

@ -3,101 +3,85 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-imperative-containers">
<title>Imperative Container Management</title>
<title>Imperative Container Management</title>
<para>We’ll cover imperative container management using
<command>nixos-container</command> first.
Be aware that container management is currently only possible
as <literal>root</literal>.</para>
<para>You create a container with
identifier <literal>foo</literal> as follows:
<para>
We’ll cover imperative container management using
<command>nixos-container</command> first. Be aware that container management
is currently only possible as <literal>root</literal>.
</para>
<para>
You create a container with identifier <literal>foo</literal> as follows:
<screen>
# nixos-container create foo
</screen>
This creates the container’s root directory in
<filename>/var/lib/containers/foo</filename> and a small configuration
file in <filename>/etc/containers/foo.conf</filename>. It also builds
the container’s initial system configuration and stores it in
<filename>/nix/var/nix/profiles/per-container/foo/system</filename>. You
can modify the initial configuration of the container on the command
line. For instance, to create a container that has
<command>sshd</command> running, with the given public key for
<literal>root</literal>:
This creates the container’s root directory in
<filename>/var/lib/containers/foo</filename> and a small configuration file
in <filename>/etc/containers/foo.conf</filename>. It also builds the
container’s initial system configuration and stores it in
<filename>/nix/var/nix/profiles/per-container/foo/system</filename>. You can
modify the initial configuration of the container on the command line. For
instance, to create a container that has <command>sshd</command> running,
with the given public key for <literal>root</literal>:
<screen>
# nixos-container create foo --config '
<xref linkend="opt-services.openssh.enable"/> = true;
<link linkend="opt-users.users._name__.openssh.authorizedKeys.keys">users.extraUsers.root.openssh.authorizedKeys.keys</link> = ["ssh-dss AAAAB3N…"];
'
</screen>
</para>
</para>
<para>Creating a container does not start it. To start the container,
run:
<para>
Creating a container does not start it. To start the container, run:
<screen>
# nixos-container start foo
</screen>
This command will return as soon as the container has booted and has
reached <literal>multi-user.target</literal>. On the host, the
container runs within a systemd unit called
<literal>container@<replaceable>container-name</replaceable>.service</literal>.
Thus, if something went wrong, you can get status info using
<command>systemctl</command>:
This command will return as soon as the container has booted and has reached
<literal>multi-user.target</literal>. On the host, the container runs within
a systemd unit called
<literal>container@<replaceable>container-name</replaceable>.service</literal>.
Thus, if something went wrong, you can get status info using
<command>systemctl</command>:
<screen>
# systemctl status container@foo
</screen>
</para>
</para>
<para>If the container has started successfully, you can log in as
root using the <command>root-login</command> operation:
<para>
If the container has started successfully, you can log in as root using the
<command>root-login</command> operation:
<screen>
# nixos-container root-login foo
[root@foo:~]#
</screen>
Note that only root on the host can do this (since there is no
authentication). You can also get a regular login prompt using the
<command>login</command> operation, which is available to all users on
the host:
Note that only root on the host can do this (since there is no
authentication). You can also get a regular login prompt using the
<command>login</command> operation, which is available to all users on the
host:
<screen>
# nixos-container login foo
foo login: alice
Password: ***
</screen>
With <command>nixos-container run</command>, you can execute arbitrary
commands in the container:
With <command>nixos-container run</command>, you can execute arbitrary
commands in the container:
<screen>
# nixos-container run foo -- uname -a
Linux foo 3.4.82 #1-NixOS SMP Thu Mar 20 14:44:05 UTC 2014 x86_64 GNU/Linux
</screen>
</para>
</para>
<para>There are several ways to change the configuration of the
container. First, on the host, you can edit
<literal>/var/lib/container/<replaceable>name</replaceable>/etc/nixos/configuration.nix</literal>,
and run
<para>
There are several ways to change the configuration of the container. First,
on the host, you can edit
<literal>/var/lib/container/<replaceable>name</replaceable>/etc/nixos/configuration.nix</literal>,
and run
<screen>
# nixos-container update foo
</screen>
This will build and activate the new configuration. You can also
specify a new configuration on the command line:
This will build and activate the new configuration. You can also specify a
new configuration on the command line:
<screen>
# nixos-container update foo --config '
<xref linkend="opt-services.httpd.enable"/> = true;
@ -108,26 +92,25 @@ specify a new configuration on the command line:
# curl http://$(nixos-container show-ip foo)/
&lt;!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">…
</screen>
However, note that this will overwrite the container’s
<filename>/etc/nixos/configuration.nix</filename>.
</para>
However, note that this will overwrite the container’s
<filename>/etc/nixos/configuration.nix</filename>.</para>
<para>Alternatively, you can change the configuration from within the
container itself by running <command>nixos-rebuild switch</command>
inside the container. Note that the container by default does not have
a copy of the NixOS channel, so you should run <command>nix-channel
--update</command> first.</para>
<para>Containers can be stopped and started using
<literal>nixos-container stop</literal> and <literal>nixos-container
start</literal>, respectively, or by using
<command>systemctl</command> on the container’s service unit. To
destroy a container, including its file system, do
<para>
Alternatively, you can change the configuration from within the container
itself by running <command>nixos-rebuild switch</command> inside the
container. Note that the container by default does not have a copy of the
NixOS channel, so you should run <command>nix-channel --update</command>
first.
</para>
<para>
Containers can be stopped and started using <literal>nixos-container
stop</literal> and <literal>nixos-container start</literal>, respectively, or
by using <command>systemctl</command> on the container’s service unit. To
destroy a container, including its file system, do
<screen>
# nixos-container destroy foo
</screen>
</para>
</para>
</section>

49
nixos/doc/manual/administration/logging.xml
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@ -3,26 +3,20 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-logging">
<title>Logging</title>
<para>System-wide logging is provided by systemd’s
<emphasis>journal</emphasis>, which subsumes traditional logging
daemons such as syslogd and klogd. Log entries are kept in binary
files in <filename>/var/log/journal/</filename>. The command
<literal>journalctl</literal> allows you to see the contents of the
journal. For example,
<title>Logging</title>
<para>
System-wide logging is provided by systemd’s <emphasis>journal</emphasis>,
which subsumes traditional logging daemons such as syslogd and klogd. Log
entries are kept in binary files in <filename>/var/log/journal/</filename>.
The command <literal>journalctl</literal> allows you to see the contents of
the journal. For example,
<screen>
$ journalctl -b
</screen>
shows all journal entries since the last reboot. (The output of
<command>journalctl</command> is piped into <command>less</command> by
default.) You can use various options and match operators to restrict
output to messages of interest. For instance, to get all messages
from PostgreSQL:
shows all journal entries since the last reboot. (The output of
<command>journalctl</command> is piped into <command>less</command> by
default.) You can use various options and match operators to restrict output
to messages of interest. For instance, to get all messages from PostgreSQL:
<screen>
$ journalctl -u postgresql.service
-- Logs begin at Mon, 2013-01-07 13:28:01 CET, end at Tue, 2013-01-08 01:09:57 CET. --
@ -32,21 +26,18 @@ Jan 07 15:44:14 hagbard postgres[2681]: [2-1] LOG: database system is shut down
Jan 07 15:45:10 hagbard postgres[2532]: [1-1] LOG: database system was shut down at 2013-01-07 15:44:14 CET
Jan 07 15:45:13 hagbard postgres[2500]: [1-1] LOG: database system is ready to accept connections
</screen>
Or to get all messages since the last reboot that have at least a
“critical” severity level:
Or to get all messages since the last reboot that have at least a
“critical” severity level:
<screen>
$ journalctl -b -p crit
Dec 17 21:08:06 mandark sudo[3673]: pam_unix(sudo:auth): auth could not identify password for [alice]
Dec 29 01:30:22 mandark kernel[6131]: [1053513.909444] CPU6: Core temperature above threshold, cpu clock throttled (total events = 1)
</screen>
</para>
<para>The system journal is readable by root and by users in the
<literal>wheel</literal> and <literal>systemd-journal</literal>
groups. All users have a private journal that can be read using
<command>journalctl</command>.</para>
</para>
<para>
The system journal is readable by root and by users in the
<literal>wheel</literal> and <literal>systemd-journal</literal> groups. All
users have a private journal that can be read using
<command>journalctl</command>.
</para>
</chapter>

16
nixos/doc/manual/administration/maintenance-mode.xml
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@ -3,16 +3,14 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-maintenance-mode">
<title>Maintenance Mode</title>
<title>Maintenance Mode</title>
<para>You can enter rescue mode by running:
<para>
You can enter rescue mode by running:
<screen>
# systemctl rescue</screen>
This will eventually give you a single-user root shell. Systemd will
stop (almost) all system services. To get out of maintenance mode,
just exit from the rescue shell.</para>
This will eventually give you a single-user root shell. Systemd will stop
(almost) all system services. To get out of maintenance mode, just exit from
the rescue shell.
</para>
</section>

34
nixos/doc/manual/administration/network-problems.xml
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@ -3,31 +3,25 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-nix-network-issues">
<title>Network Problems</title>
<title>Network Problems</title>
<para>Nix uses a so-called <emphasis>binary cache</emphasis> to
optimise building a package from source into downloading it as a
pre-built binary. That is, whenever a command like
<command>nixos-rebuild</command> needs a path in the Nix store, Nix
will try to download that path from the Internet rather than build it
from source. The default binary cache is
<uri>https://cache.nixos.org/</uri>. If this cache is unreachable,
Nix operations may take a long time due to HTTP connection timeouts.
You can disable the use of the binary cache by adding <option>--option
use-binary-caches false</option>, e.g.
<para>
Nix uses a so-called <emphasis>binary cache</emphasis> to optimise building a
package from source into downloading it as a pre-built binary. That is,
whenever a command like <command>nixos-rebuild</command> needs a path in the
Nix store, Nix will try to download that path from the Internet rather than
build it from source. The default binary cache is
<uri>https://cache.nixos.org/</uri>. If this cache is unreachable, Nix
operations may take a long time due to HTTP connection timeouts. You can
disable the use of the binary cache by adding <option>--option
use-binary-caches false</option>, e.g.
<screen>
# nixos-rebuild switch --option use-binary-caches false
</screen>
If you have an alternative binary cache at your disposal, you can use
it instead:
If you have an alternative binary cache at your disposal, you can use it
instead:
<screen>
# nixos-rebuild switch --option binary-caches http://my-cache.example.org/
</screen>
</para>
</para>
</section>

49
nixos/doc/manual/administration/rebooting.xml
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@ -3,42 +3,33 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-rebooting">
<title>Rebooting and Shutting Down</title>
<para>The system can be shut down (and automatically powered off) by
doing:
<title>Rebooting and Shutting Down</title>
<para>
The system can be shut down (and automatically powered off) by doing:
<screen>
# shutdown
</screen>
This is equivalent to running <command>systemctl
poweroff</command>.</para>
<para>To reboot the system, run
This is equivalent to running <command>systemctl poweroff</command>.
</para>
<para>
To reboot the system, run
<screen>
# reboot
</screen>
which is equivalent to <command>systemctl reboot</command>.
Alternatively, you can quickly reboot the system using
<literal>kexec</literal>, which bypasses the BIOS by directly loading
the new kernel into memory:
which is equivalent to <command>systemctl reboot</command>. Alternatively,
you can quickly reboot the system using <literal>kexec</literal>, which
bypasses the BIOS by directly loading the new kernel into memory:
<screen>
# systemctl kexec
</screen>
</para>
<para>The machine can be suspended to RAM (if supported) using
<command>systemctl suspend</command>, and suspended to disk using
<command>systemctl hibernate</command>.</para>
<para>These commands can be run by any user who is logged in locally,
i.e. on a virtual console or in X11; otherwise, the user is asked for
authentication.</para>
</para>
<para>
The machine can be suspended to RAM (if supported) using <command>systemctl
suspend</command>, and suspended to disk using <command>systemctl
hibernate</command>.
</para>
<para>
These commands can be run by any user who is logged in locally, i.e. on a
virtual console or in X11; otherwise, the user is asked for authentication.
</para>
</chapter>

49
nixos/doc/manual/administration/rollback.xml
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@ -3,46 +3,39 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-rollback">
<title>Rolling Back Configuration Changes</title>
<title>Rolling Back Configuration Changes</title>
<para>After running <command>nixos-rebuild</command> to switch to a
new configuration, you may find that the new configuration doesn’t
work very well. In that case, there are several ways to return to a
previous configuration.</para>
<para>First, the GRUB boot manager allows you to boot into any
previous configuration that hasn’t been garbage-collected. These
configurations can be found under the GRUB submenu “NixOS - All
configurations”. This is especially useful if the new configuration
fails to boot. After the system has booted, you can make the selected
configuration the default for subsequent boots:
<para>
After running <command>nixos-rebuild</command> to switch to a new
configuration, you may find that the new configuration doesn’t work very
well. In that case, there are several ways to return to a previous
configuration.
</para>
<para>
First, the GRUB boot manager allows you to boot into any previous
configuration that hasn’t been garbage-collected. These configurations can
be found under the GRUB submenu “NixOS - All configurations”. This is
especially useful if the new configuration fails to boot. After the system
has booted, you can make the selected configuration the default for
subsequent boots:
<screen>
# /run/current-system/bin/switch-to-configuration boot</screen>
</para>
</para>
<para>Second, you can switch to the previous configuration in a running
system:
<para>
Second, you can switch to the previous configuration in a running system:
<screen>
# nixos-rebuild switch --rollback</screen>
This is equivalent to running:
This is equivalent to running:
<screen>
# /nix/var/nix/profiles/system-<replaceable>N</replaceable>-link/bin/switch-to-configuration switch</screen>
where <replaceable>N</replaceable> is the number of the NixOS system
configuration. To get a list of the available configurations, do:
where <replaceable>N</replaceable> is the number of the NixOS system
configuration. To get a list of the available configurations, do:
<screen>
$ ls -l /nix/var/nix/profiles/system-*-link
<replaceable>...</replaceable>
lrwxrwxrwx 1 root root 78 Aug 12 13:54 /nix/var/nix/profiles/system-268-link -> /nix/store/202b...-nixos-13.07pre4932_5a676e4-4be1055
</screen>
</para>
</para>
</section>

33
nixos/doc/manual/administration/running.xml
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@ -3,22 +3,19 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="ch-running">
<title>Administration</title>
<partintro>
<para>This chapter describes various aspects of managing a running
NixOS system, such as how to use the <command>systemd</command>
service manager.</para>
</partintro>
<xi:include href="service-mgmt.xml" />
<xi:include href="rebooting.xml" />
<xi:include href="user-sessions.xml" />
<xi:include href="control-groups.xml" />
<xi:include href="logging.xml" />
<xi:include href="cleaning-store.xml" />
<xi:include href="containers.xml" />
<xi:include href="troubleshooting.xml" />
<title>Administration</title>
<partintro>
<para>
This chapter describes various aspects of managing a running NixOS system,
such as how to use the <command>systemd</command> service manager.
</para>
</partintro>
<xi:include href="service-mgmt.xml" />
<xi:include href="rebooting.xml" />
<xi:include href="user-sessions.xml" />
<xi:include href="control-groups.xml" />
<xi:include href="logging.xml" />
<xi:include href="cleaning-store.xml" />
<xi:include href="containers.xml" />
<xi:include href="troubleshooting.xml" />
</part>

73
nixos/doc/manual/administration/service-mgmt.xml
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@ -3,26 +3,23 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-systemctl">
<title>Service Management</title>
<para>In NixOS, all system services are started and monitored using
the systemd program. Systemd is the “init” process of the system
(i.e. PID 1), the parent of all other processes. It manages a set of
so-called “units”, which can be things like system services
(programs), but also mount points, swap files, devices, targets
(groups of units) and more. Units can have complex dependencies; for
instance, one unit can require that another unit must be successfully
started before the first unit can be started. When the system boots,
it starts a unit named <literal>default.target</literal>; the
dependencies of this unit cause all system services to be started,
file systems to be mounted, swap files to be activated, and so
on.</para>
<para>The command <command>systemctl</command> is the main way to
interact with <command>systemd</command>. Without any arguments, it
shows the status of active units:
<title>Service Management</title>
<para>
In NixOS, all system services are started and monitored using the systemd
program. Systemd is the “init” process of the system (i.e. PID 1), the
parent of all other processes. It manages a set of so-called “units”,
which can be things like system services (programs), but also mount points,
swap files, devices, targets (groups of units) and more. Units can have
complex dependencies; for instance, one unit can require that another unit
must be successfully started before the first unit can be started. When the
system boots, it starts a unit named <literal>default.target</literal>; the
dependencies of this unit cause all system services to be started, file
systems to be mounted, swap files to be activated, and so on.
</para>
<para>
The command <command>systemctl</command> is the main way to interact with
<command>systemd</command>. Without any arguments, it shows the status of
active units:
<screen>
$ systemctl
-.mount loaded active mounted /
@ -31,12 +28,10 @@ sshd.service loaded active running SSH Daemon
graphical.target loaded active active Graphical Interface
<replaceable>...</replaceable>
</screen>
</para>
<para>You can ask for detailed status information about a unit, for
instance, the PostgreSQL database service:
</para>
<para>
You can ask for detailed status information about a unit, for instance, the
PostgreSQL database service:
<screen>
$ systemctl status postgresql.service
postgresql.service - PostgreSQL Server
@ -56,28 +51,22 @@ Jan 07 15:55:57 hagbard postgres[2390]: [1-1] LOG: database system is ready to
Jan 07 15:55:57 hagbard postgres[2420]: [1-1] LOG: autovacuum launcher started
Jan 07 15:55:57 hagbard systemd[1]: Started PostgreSQL Server.
</screen>
Note that this shows the status of the unit (active and running), all
the processes belonging to the service, as well as the most recent log
messages from the service.
</para>
<para>Units can be stopped, started or restarted:
Note that this shows the status of the unit (active and running), all the
processes belonging to the service, as well as the most recent log messages
from the service.
</para>
<para>
Units can be stopped, started or restarted:
<screen>
# systemctl stop postgresql.service
# systemctl start postgresql.service
# systemctl restart postgresql.service
</screen>
These operations are synchronous: they wait until the service has
finished starting or stopping (or has failed). Starting a unit will
cause the dependencies of that unit to be started as well (if
necessary).</para>
These operations are synchronous: they wait until the service has finished
starting or stopping (or has failed). Starting a unit will cause the
dependencies of that unit to be started as well (if necessary).
</para>
<!-- - cgroups: each service and user session is a cgroup
- cgroup resource management -->
</chapter>

43
nixos/doc/manual/administration/store-corruption.xml
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@ -3,35 +3,34 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-nix-store-corruption">
<title>Nix Store Corruption</title>
<title>Nix Store Corruption</title>
<para>After a system crash, it’s possible for files in the Nix store
to become corrupted. (For instance, the Ext4 file system has the
tendency to replace un-synced files with zero bytes.) NixOS tries
hard to prevent this from happening: it performs a
<command>sync</command> before switching to a new configuration, and
Nix’s database is fully transactional. If corruption still occurs,
you may be able to fix it automatically.</para>
<para>If the corruption is in a path in the closure of the NixOS
system configuration, you can fix it by doing
<para>
After a system crash, it’s possible for files in the Nix store to become
corrupted. (For instance, the Ext4 file system has the tendency to replace
un-synced files with zero bytes.) NixOS tries hard to prevent this from
happening: it performs a <command>sync</command> before switching to a new
configuration, and Nix’s database is fully transactional. If corruption
still occurs, you may be able to fix it automatically.
</para>
<para>
If the corruption is in a path in the closure of the NixOS system
configuration, you can fix it by doing
<screen>
# nixos-rebuild switch --repair
</screen>
This will cause Nix to check every path in the closure, and if its
cryptographic hash differs from the hash recorded in Nix’s database, the
path is rebuilt or redownloaded.
</para>
This will cause Nix to check every path in the closure, and if its
cryptographic hash differs from the hash recorded in Nix’s database,
the path is rebuilt or redownloaded.</para>
<para>You can also scan the entire Nix store for corrupt paths:
<para>
You can also scan the entire Nix store for corrupt paths:
<screen>
# nix-store --verify --check-contents --repair
</screen>
Any corrupt paths will be redownloaded if they’re available in a
binary cache; otherwise, they cannot be repaired.</para>
Any corrupt paths will be redownloaded if they’re available in a binary
cache; otherwise, they cannot be repaired.
</para>
</section>

22
nixos/doc/manual/administration/troubleshooting.xml
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@ -3,16 +3,14 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="ch-troubleshooting">
<title>Troubleshooting</title>
<para>This chapter describes solutions to common problems you might
encounter when you manage your NixOS system.</para>
<xi:include href="boot-problems.xml" />
<xi:include href="maintenance-mode.xml" />
<xi:include href="rollback.xml" />
<xi:include href="store-corruption.xml" />
<xi:include href="network-problems.xml" />
<title>Troubleshooting</title>
<para>
This chapter describes solutions to common problems you might encounter when
you manage your NixOS system.
</para>
<xi:include href="boot-problems.xml" />
<xi:include href="maintenance-mode.xml" />
<xi:include href="rollback.xml" />
<xi:include href="store-corruption.xml" />
<xi:include href="network-problems.xml" />
</chapter>

38
nixos/doc/manual/administration/user-sessions.xml
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@ -3,14 +3,12 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-user-sessions">
<title>User Sessions</title>
<para>Systemd keeps track of all users who are logged into the system
(e.g. on a virtual console or remotely via SSH). The command
<command>loginctl</command> allows querying and manipulating user
sessions. For instance, to list all user sessions:
<title>User Sessions</title>
<para>
Systemd keeps track of all users who are logged into the system (e.g. on a
virtual console or remotely via SSH). The command <command>loginctl</command>
allows querying and manipulating user sessions. For instance, to list all
user sessions:
<screen>
$ loginctl
SESSION UID USER SEAT
@ -18,12 +16,10 @@ $ loginctl
c3 0 root seat0
c4 500 alice
</screen>
This shows that two users are logged in locally, while another is
logged in remotely. (“Seats” are essentially the combinations of
displays and input devices attached to the system; usually, there is
only one seat.) To get information about a session:
This shows that two users are logged in locally, while another is logged in
remotely. (“Seats” are essentially the combinations of displays and input
devices attached to the system; usually, there is only one seat.) To get
information about a session:
<screen>
$ loginctl session-status c3
c3 - root (0)
@ -38,16 +34,12 @@ c3 - root (0)
├─10339 -bash
└─10355 w3m nixos.org
</screen>
This shows that the user is logged in on virtual console 3. It also
lists the processes belonging to this session. Since systemd keeps
track of this, you can terminate a session in a way that ensures that
all the session’s processes are gone:
This shows that the user is logged in on virtual console 3. It also lists the
processes belonging to this session. Since systemd keeps track of this, you
can terminate a session in a way that ensures that all the session’s
processes are gone:
<screen>
# loginctl terminate-session c3
</screen>
</para>
</para>
</chapter>

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nixos/doc/manual/configuration/abstractions.xml
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@ -3,12 +3,11 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-module-abstractions">
<title>Abstractions</title>
<title>Abstractions</title>
<para>If you find yourself repeating yourself over and over, it’s time
to abstract. Take, for instance, this Apache HTTP Server configuration:
<para>
If you find yourself repeating yourself over and over, it’s time to
abstract. Take, for instance, this Apache HTTP Server configuration:
<programlisting>
{
<xref linkend="opt-services.httpd.virtualHosts"/> =
@ -28,11 +27,9 @@ to abstract. Take, for instance, this Apache HTTP Server configuration:
];
}
</programlisting>
It defines two virtual hosts with nearly identical configuration; the
only difference is that the second one has SSL enabled. To prevent
this duplication, we can use a <literal>let</literal>:
It defines two virtual hosts with nearly identical configuration; the only
difference is that the second one has SSL enabled. To prevent this
duplication, we can use a <literal>let</literal>:
<programlisting>
let
exampleOrgCommon =
@ -53,17 +50,16 @@ in
];
}
</programlisting>
The <literal>let exampleOrgCommon = <replaceable>...</replaceable></literal>
defines a variable named <literal>exampleOrgCommon</literal>. The
<literal>//</literal> operator merges two attribute sets, so the
configuration of the second virtual host is the set
<literal>exampleOrgCommon</literal> extended with the SSL options.
</para>
The <literal>let exampleOrgCommon =
<replaceable>...</replaceable></literal> defines a variable named
<literal>exampleOrgCommon</literal>. The <literal>//</literal>
operator merges two attribute sets, so the configuration of the second
virtual host is the set <literal>exampleOrgCommon</literal> extended
with the SSL options.</para>
<para>You can write a <literal>let</literal> wherever an expression is
allowed. Thus, you also could have written:
<para>
You can write a <literal>let</literal> wherever an expression is allowed.
Thus, you also could have written:
<programlisting>
{
<xref linkend="opt-services.httpd.virtualHosts"/> =
@ -73,17 +69,16 @@ allowed. Thus, you also could have written:
];
}
</programlisting>
but not <literal>{ let exampleOrgCommon = <replaceable>...</replaceable>; in
<replaceable>...</replaceable>; }</literal> since attributes (as opposed to
attribute values) are not expressions.
</para>
but not <literal>{ let exampleOrgCommon =
<replaceable>...</replaceable>; in <replaceable>...</replaceable>;
}</literal> since attributes (as opposed to attribute values) are not
expressions.</para>
<para><emphasis>Functions</emphasis> provide another method of
abstraction. For instance, suppose that we want to generate lots of
different virtual hosts, all with identical configuration except for
the host name. This can be done as follows:
<para>
<emphasis>Functions</emphasis> provide another method of abstraction. For
instance, suppose that we want to generate lots of different virtual hosts,
all with identical configuration except for the host name. This can be done
as follows:
<programlisting>
{
<xref linkend="opt-services.httpd.virtualHosts"/> =
@ -101,16 +96,15 @@ the host name. This can be done as follows:
];
}
</programlisting>
Here, <varname>makeVirtualHost</varname> is a function that takes a single
argument <literal>name</literal> and returns the configuration for a virtual
host. That function is then called for several names to produce the list of
virtual host configurations.
</para>
Here, <varname>makeVirtualHost</varname> is a function that takes a
single argument <literal>name</literal> and returns the configuration
for a virtual host. That function is then called for several names to
produce the list of virtual host configurations.</para>
<para>We can further improve on this by using the function
<varname>map</varname>, which applies another function to every
element in a list:
<para>
We can further improve on this by using the function <varname>map</varname>,
which applies another function to every element in a list:
<programlisting>
{
<xref linkend="opt-services.httpd.virtualHosts"/> =
@ -120,16 +114,15 @@ element in a list:
[ "example.org" "example.com" "example.gov" "example.nl" ];
}
</programlisting>
(The function <literal>map</literal> is called a <emphasis>higher-order
function</emphasis> because it takes another function as an argument.)
</para>
(The function <literal>map</literal> is called a
<emphasis>higher-order function</emphasis> because it takes another
function as an argument.)</para>
<para>What if you need more than one argument, for instance, if we
want to use a different <literal>documentRoot</literal> for each
virtual host? Then we can make <varname>makeVirtualHost</varname> a
function that takes a <emphasis>set</emphasis> as its argument, like this:
<para>
What if you need more than one argument, for instance, if we want to use a
different <literal>documentRoot</literal> for each virtual host? Then we can
make <varname>makeVirtualHost</varname> a function that takes a
<emphasis>set</emphasis> as its argument, like this:
<programlisting>
{
<xref linkend="opt-services.httpd.virtualHosts"/> =
@ -147,10 +140,9 @@ function that takes a <emphasis>set</emphasis> as its argument, like this:
];
}
</programlisting>
But in this case (where every root is a subdirectory of
<filename>/sites</filename> named after the virtual host), it would
have been shorter to define <varname>makeVirtualHost</varname> as
But in this case (where every root is a subdirectory of
<filename>/sites</filename> named after the virtual host), it would have been
shorter to define <varname>makeVirtualHost</varname> as
<programlisting>
makeVirtualHost = name:
{ hostName = name;
@ -158,9 +150,7 @@ makeVirtualHost = name:
adminAddr = "alice@example.org";
};
</programlisting>
Here, the construct
<literal>${<replaceable>...</replaceable>}</literal> allows the result
of an expression to be spliced into a string.</para>
Here, the construct <literal>${<replaceable>...</replaceable>}</literal>
allows the result of an expression to be spliced into a string.
</para>
</section>

18
nixos/doc/manual/configuration/ad-hoc-network-config.xml
View File

@ -3,22 +3,18 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="ad-hoc-network-config">
<title>Ad-Hoc Configuration</title>
<title>Ad-Hoc Configuration</title>
<para>You can use <xref linkend="opt-networking.localCommands"/> to specify
shell commands to be run at the end of
<literal>network-setup.service</literal>. This is useful for doing
network configuration not covered by the existing NixOS modules. For
instance, to statically configure an IPv6 address:
<para>
You can use <xref linkend="opt-networking.localCommands"/> to specify shell
commands to be run at the end of <literal>network-setup.service</literal>.
This is useful for doing network configuration not covered by the existing
NixOS modules. For instance, to statically configure an IPv6 address:
<programlisting>
<xref linkend="opt-networking.localCommands"/> =
''
ip -6 addr add 2001:610:685:1::1/64 dev eth0
'';
</programlisting>
</para>
</para>
</section>

74
nixos/doc/manual/configuration/ad-hoc-packages.xml
View File

@ -3,61 +3,59 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-ad-hoc-packages">
<title>Ad-Hoc Package Management</title>
<title>Ad-Hoc Package Management</title>
<para>With the command <command>nix-env</command>, you can install and
uninstall packages from the command line. For instance, to install
Mozilla Thunderbird:
<para>
With the command <command>nix-env</command>, you can install and uninstall
packages from the command line. For instance, to install Mozilla Thunderbird:
<screen>
$ nix-env -iA nixos.thunderbird</screen>
If you invoke this as root, the package is installed in the Nix profile
<filename>/nix/var/nix/profiles/default</filename> and visible to all users
of the system; otherwise, the package ends up in
<filename>/nix/var/nix/profiles/per-user/<replaceable>username</replaceable>/profile</filename>
and is not visible to other users. The <option>-A</option> flag specifies the
package by its attribute name; without it, the package is installed by
matching against its package name (e.g. <literal>thunderbird</literal>). The
latter is slower because it requires matching against all available Nix
packages, and is ambiguous if there are multiple matching packages.
</para>
If you invoke this as root, the package is installed in the Nix
profile <filename>/nix/var/nix/profiles/default</filename> and visible
to all users of the system; otherwise, the package ends up in
<filename>/nix/var/nix/profiles/per-user/<replaceable>username</replaceable>/profile</filename>
and is not visible to other users. The <option>-A</option> flag
specifies the package by its attribute name; without it, the package
is installed by matching against its package name
(e.g. <literal>thunderbird</literal>). The latter is slower because
it requires matching against all available Nix packages, and is
ambiguous if there are multiple matching packages.</para>
<para>Packages come from the NixOS channel. You typically upgrade a
package by updating to the latest version of the NixOS channel:
<para>
Packages come from the NixOS channel. You typically upgrade a package by
updating to the latest version of the NixOS channel:
<screen>
$ nix-channel --update nixos
</screen>
and then running <literal>nix-env -i</literal> again. Other packages
in the profile are <emphasis>not</emphasis> affected; this is the
crucial difference with the declarative style of package management,
where running <command>nixos-rebuild switch</command> causes all
packages to be updated to their current versions in the NixOS channel.
You can however upgrade all packages for which there is a newer
version by doing:
and then running <literal>nix-env -i</literal> again. Other packages in the
profile are <emphasis>not</emphasis> affected; this is the crucial difference
with the declarative style of package management, where running
<command>nixos-rebuild switch</command> causes all packages to be updated to
their current versions in the NixOS channel. You can however upgrade all
packages for which there is a newer version by doing:
<screen>
$ nix-env -u '*'
</screen>
</para>
</para>
<para>A package can be uninstalled using the <option>-e</option>
flag:
<para>
A package can be uninstalled using the <option>-e</option> flag:
<screen>
$ nix-env -e thunderbird
</screen>
</para>
</para>
<para>Finally, you can roll back an undesirable
<command>nix-env</command> action:
<para>
Finally, you can roll back an undesirable <command>nix-env</command> action:
<screen>
$ nix-env --rollback
</screen>
</para>
<para><command>nix-env</command> has many more flags. For details,
see the
<citerefentry><refentrytitle>nix-env</refentrytitle><manvolnum>1</manvolnum></citerefentry>
manpage or the Nix manual.</para>
</para>
<para>
<command>nix-env</command> has many more flags. For details, see the
<citerefentry>
<refentrytitle>nix-env</refentrytitle>
<manvolnum>1</manvolnum></citerefentry> manpage or the Nix manual.
</para>
</section>

59
nixos/doc/manual/configuration/adding-custom-packages.xml
View File

@ -3,43 +3,36 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-custom-packages">
<title>Adding Custom Packages</title>
<title>Adding Custom Packages</title>
<para>It’s possible that a package you need is not available in NixOS.
In that case, you can do two things. First, you can clone the Nixpkgs
repository, add the package to your clone, and (optionally) submit a
patch or pull request to have it accepted into the main Nixpkgs
repository. This is described in detail in the <link
xlink:href="http://nixos.org/nixpkgs/manual">Nixpkgs manual</link>.
In short, you clone Nixpkgs:
<para>
It’s possible that a package you need is not available in NixOS. In that
case, you can do two things. First, you can clone the Nixpkgs repository, add
the package to your clone, and (optionally) submit a patch or pull request to
have it accepted into the main Nixpkgs repository. This is described in
detail in the <link
xlink:href="http://nixos.org/nixpkgs/manual">Nixpkgs
manual</link>. In short, you clone Nixpkgs:
<screen>
$ git clone git://github.com/NixOS/nixpkgs.git
$ cd nixpkgs
</screen>
Then you write and test the package as described in the Nixpkgs
manual. Finally, you add it to
<literal>environment.systemPackages</literal>, e.g.
Then you write and test the package as described in the Nixpkgs manual.
Finally, you add it to <literal>environment.systemPackages</literal>, e.g.
<programlisting>
<xref linkend="opt-environment.systemPackages"/> = [ pkgs.my-package ];
</programlisting>
and you run <command>nixos-rebuild</command>, specifying your own
Nixpkgs tree:
and you run <command>nixos-rebuild</command>, specifying your own Nixpkgs
tree:
<screen>
# nixos-rebuild switch -I nixpkgs=/path/to/my/nixpkgs</screen>
</para>
</para>
<para>The second possibility is to add the package outside of the
Nixpkgs tree. For instance, here is how you specify a build of the
<link xlink:href="http://www.gnu.org/software/hello/">GNU Hello</link>
package directly in <filename>configuration.nix</filename>:
<para>
The second possibility is to add the package outside of the Nixpkgs tree. For
instance, here is how you specify a build of the
<link xlink:href="http://www.gnu.org/software/hello/">GNU Hello</link>
package directly in <filename>configuration.nix</filename>:
<programlisting>
<xref linkend="opt-environment.systemPackages"/> =
let
@ -53,13 +46,12 @@ package directly in <filename>configuration.nix</filename>:
in
[ my-hello ];
</programlisting>
Of course, you can also move the definition of
<literal>my-hello</literal> into a separate Nix expression, e.g.
Of course, you can also move the definition of <literal>my-hello</literal>
into a separate Nix expression, e.g.
<programlisting>
<xref linkend="opt-environment.systemPackages"/> = [ (import ./my-hello.nix) ];
</programlisting>
where <filename>my-hello.nix</filename> contains:
where <filename>my-hello.nix</filename> contains:
<programlisting>
with import &lt;nixpkgs> {}; # bring all of Nixpkgs into scope
@ -71,14 +63,11 @@ stdenv.mkDerivation rec {
};
}
</programlisting>
This allows testing the package easily:
This allows testing the package easily:
<screen>
$ nix-build my-hello.nix
$ ./result/bin/hello
Hello, world!
</screen>
</para>
</para>
</section>

215
nixos/doc/manual/configuration/config-file.xml
View File

@ -3,28 +3,25 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-configuration-file">
<title>NixOS Configuration File</title>
<title>NixOS Configuration File</title>
<para>The NixOS configuration file generally looks like this:
<para>
The NixOS configuration file generally looks like this:
<programlisting>
{ config, pkgs, ... }:
{ <replaceable>option definitions</replaceable>
}
</programlisting>
The first line (<literal>{ config, pkgs, ... }:</literal>) denotes
that this is actually a function that takes at least the two arguments
<varname>config</varname> and <varname>pkgs</varname>. (These are
explained later.) The function returns a <emphasis>set</emphasis> of
option definitions (<literal>{ <replaceable>...</replaceable> }</literal>). These definitions have the
form <literal><replaceable>name</replaceable> =
<replaceable>value</replaceable></literal>, where
<replaceable>name</replaceable> is the name of an option and
<replaceable>value</replaceable> is its value. For example,
The first line (<literal>{ config, pkgs, ... }:</literal>) denotes that this
is actually a function that takes at least the two arguments
<varname>config</varname> and <varname>pkgs</varname>. (These are explained
later.) The function returns a <emphasis>set</emphasis> of option definitions
(<literal>{ <replaceable>...</replaceable> }</literal>). These definitions
have the form <literal><replaceable>name</replaceable> =
<replaceable>value</replaceable></literal>, where
<replaceable>name</replaceable> is the name of an option and
<replaceable>value</replaceable> is its value. For example,
<programlisting>
{ config, pkgs, ... }:
@ -33,19 +30,19 @@ form <literal><replaceable>name</replaceable> =
<xref linkend="opt-services.httpd.documentRoot"/> = "/webroot";
}
</programlisting>
defines a configuration with three option definitions that together enable
the Apache HTTP Server with <filename>/webroot</filename> as the document
root.
</para>
defines a configuration with three option definitions that together
enable the Apache HTTP Server with <filename>/webroot</filename> as
the document root.</para>
<para>Sets can be nested, and in fact dots in option names are
shorthand for defining a set containing another set. For instance,
<xref linkend="opt-services.httpd.enable"/> defines a set named
<varname>services</varname> that contains a set named
<varname>httpd</varname>, which in turn contains an option definition
named <varname>enable</varname> with value <literal>true</literal>.
This means that the example above can also be written as:
<para>
Sets can be nested, and in fact dots in option names are shorthand for
defining a set containing another set. For instance,
<xref linkend="opt-services.httpd.enable"/> defines a set named
<varname>services</varname> that contains a set named
<varname>httpd</varname>, which in turn contains an option definition named
<varname>enable</varname> with value <literal>true</literal>. This means that
the example above can also be written as:
<programlisting>
{ config, pkgs, ... }:
@ -58,46 +55,44 @@ This means that the example above can also be written as:
};
}
</programlisting>
which may be more convenient if you have lots of option definitions that
share the same prefix (such as <literal>services.httpd</literal>).
</para>
which may be more convenient if you have lots of option definitions
that share the same prefix (such as
<literal>services.httpd</literal>).</para>
<para>NixOS checks your option definitions for correctness. For
instance, if you try to define an option that doesn’t exist (that is,
doesn’t have a corresponding <emphasis>option declaration</emphasis>),
<command>nixos-rebuild</command> will give an error like:
<para>
NixOS checks your option definitions for correctness. For instance, if you
try to define an option that doesn’t exist (that is, doesn’t have a
corresponding <emphasis>option declaration</emphasis>),
<command>nixos-rebuild</command> will give an error like:
<screen>
The option `services.httpd.enable' defined in `/etc/nixos/configuration.nix' does not exist.
</screen>
Likewise, values in option definitions must have a correct type. For
instance, <option>services.httpd.enable</option> must be a Boolean
(<literal>true</literal> or <literal>false</literal>). Trying to give
it a value of another type, such as a string, will cause an error:
Likewise, values in option definitions must have a correct type. For
instance, <option>services.httpd.enable</option> must be a Boolean
(<literal>true</literal> or <literal>false</literal>). Trying to give it a
value of another type, such as a string, will cause an error:
<screen>
The option value `services.httpd.enable' in `/etc/nixos/configuration.nix' is not a boolean.
</screen>
</para>
</para>
<para>Options have various types of values. The most important are:
<variablelist>
<varlistentry>
<para>
Options have various types of values. The most important are:
<variablelist>
<varlistentry>
<term>Strings</term>
<listitem>
<para>Strings are enclosed in double quotes, e.g.
<para>
Strings are enclosed in double quotes, e.g.
<programlisting>
<xref linkend="opt-networking.hostName"/> = "dexter";
</programlisting>
Special characters can be escaped by prefixing them with a
backslash (e.g. <literal>\"</literal>).</para>
<para>Multi-line strings can be enclosed in <emphasis>double
single quotes</emphasis>, e.g.
Special characters can be escaped by prefixing them with a backslash
(e.g. <literal>\"</literal>).
</para>
<para>
Multi-line strings can be enclosed in <emphasis>double single
quotes</emphasis>, e.g.
<programlisting>
<xref linkend="opt-networking.extraHosts"/> =
''
@ -105,58 +100,52 @@ The option value `services.httpd.enable' in `/etc/nixos/configuration.nix' is no
10.0.0.1 server
'';
</programlisting>
The main difference is that it strips from each line
a number of spaces equal to the minimal indentation of
the string as a whole (disregarding the indentation of
empty lines), and that characters like
<literal>"</literal> and <literal>\</literal> are not special
(making it more convenient for including things like shell
code).
See more info about this in the Nix manual <link
xlink:href="https://nixos.org/nix/manual/#ssec-values">here</link>.</para>
The main difference is that it strips from each line a number of spaces
equal to the minimal indentation of the string as a whole (disregarding
the indentation of empty lines), and that characters like
<literal>"</literal> and <literal>\</literal> are not special (making it
more convenient for including things like shell code). See more info
about this in the Nix manual
<link
xlink:href="https://nixos.org/nix/manual/#ssec-values">here</link>.
</para>
</listitem>
</varlistentry>
<varlistentry>
</varlistentry>
<varlistentry>
<term>Booleans</term>
<listitem>
<para>These can be <literal>true</literal> or
<literal>false</literal>, e.g.
<para>
These can be <literal>true</literal> or <literal>false</literal>, e.g.
<programlisting>
<xref linkend="opt-networking.firewall.enable"/> = true;
<xref linkend="opt-networking.firewall.allowPing"/> = false;
</programlisting>
</para>
</para>
</listitem>
</varlistentry>
<varlistentry>
</varlistentry>
<varlistentry>
<term>Integers</term>
<listitem>
<para>For example,
<para>
For example,
<programlisting>
<xref linkend="opt-boot.kernel.sysctl"/>."net.ipv4.tcp_keepalive_time" = 60;
</programlisting>
(Note that here the attribute name
<literal>net.ipv4.tcp_keepalive_time</literal> is enclosed in
quotes to prevent it from being interpreted as a set named
<literal>net</literal> containing a set named
<literal>ipv4</literal>, and so on. This is because it’s not a
NixOS option but the literal name of a Linux kernel
setting.)</para>
<literal>net.ipv4.tcp_keepalive_time</literal> is enclosed in quotes to
prevent it from being interpreted as a set named <literal>net</literal>
containing a set named <literal>ipv4</literal>, and so on. This is
because it’s not a NixOS option but the literal name of a Linux kernel
setting.)
</para>
</listitem>
</varlistentry>
<varlistentry>
</varlistentry>
<varlistentry>
<term>Sets</term>
<listitem>
<para>Sets were introduced above. They are name/value pairs
enclosed in braces, as in the option definition
<para>
Sets were introduced above. They are name/value pairs enclosed in braces,
as in the option definition
<programlisting>
<xref linkend="opt-fileSystems"/>."/boot" =
{ device = "/dev/sda1";
@ -164,36 +153,32 @@ The option value `services.httpd.enable' in `/etc/nixos/configuration.nix' is no
options = [ "rw" "data=ordered" "relatime" ];
};
</programlisting>
</para>
</para>
</listitem>
</varlistentry>
<varlistentry>
</varlistentry>
<varlistentry>
<term>Lists</term>
<listitem>
<para>The important thing to note about lists is that list
elements are separated by whitespace, like this:
<para>
The important thing to note about lists is that list elements are
separated by whitespace, like this:
<programlisting>
<xref linkend="opt-boot.kernelModules"/> = [ "fuse" "kvm-intel" "coretemp" ];
</programlisting>
List elements can be any other type, e.g. sets:
<programlisting>
swapDevices = [ { device = "/dev/disk/by-label/swap"; } ];
</programlisting>
</para>
</para>
</listitem>
</varlistentry>
<varlistentry>
</varlistentry>
<varlistentry>
<term>Packages</term>
<listitem>
<para>Usually, the packages you need are already part of the Nix
Packages collection, which is a set that can be accessed through
the function argument <varname>pkgs</varname>. Typical uses:
<para>
Usually, the packages you need are already part of the Nix Packages
collection, which is a set that can be accessed through the function
argument <varname>pkgs</varname>. Typical uses:
<programlisting>
<xref linkend="opt-environment.systemPackages"/> =
[ pkgs.thunderbird
@ -202,16 +187,12 @@ swapDevices = [ { device = "/dev/disk/by-label/swap"; } ];
<xref linkend="opt-services.postgresql.package"/> = pkgs.postgresql90;
</programlisting>
The latter option definition changes the default PostgreSQL
package used by NixOS’s PostgreSQL service to 9.0. For more
information on packages, including how to add new ones, see
<xref linkend="sec-custom-packages"/>.</para>
The latter option definition changes the default PostgreSQL package used
by NixOS’s PostgreSQL service to 9.0. For more information on packages,
including how to add new ones, see <xref linkend="sec-custom-packages"/>.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</varlistentry>
</variablelist>
</para>
</section>

38
nixos/doc/manual/configuration/config-syntax.xml
View File

@ -3,25 +3,23 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-configuration-syntax">
<title>Configuration Syntax</title>
<para>The NixOS configuration file
<filename>/etc/nixos/configuration.nix</filename> is actually a
<emphasis>Nix expression</emphasis>, which is the Nix package
manager’s purely functional language for describing how to build
packages and configurations. This means you have all the expressive
power of that language at your disposal, including the ability to
abstract over common patterns, which is very useful when managing
complex systems. The syntax and semantics of the Nix language are
fully described in the <link
<title>Configuration Syntax</title>
<para>
The NixOS configuration file
<filename>/etc/nixos/configuration.nix</filename> is actually a <emphasis>Nix
expression</emphasis>, which is the Nix package manager’s purely functional
language for describing how to build packages and configurations. This means
you have all the expressive power of that language at your disposal,
including the ability to abstract over common patterns, which is very useful
when managing complex systems. The syntax and semantics of the Nix language
are fully described in the
<link
xlink:href="http://nixos.org/nix/manual/#chap-writing-nix-expressions">Nix
manual</link>, but here we give a short overview of the most important
constructs useful in NixOS configuration files.</para>
<xi:include href="config-file.xml" />
<xi:include href="abstractions.xml" />
<xi:include href="modularity.xml" />
<xi:include href="summary.xml" />
manual</link>, but here we give a short overview of the most important
constructs useful in NixOS configuration files.
</para>
<xi:include href="config-file.xml" />
<xi:include href="abstractions.xml" />
<xi:include href="modularity.xml" />
<xi:include href="summary.xml" />
</chapter>

44
nixos/doc/manual/configuration/configuration.xml
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@ -3,30 +3,24 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="ch-configuration">
<title>Configuration</title>
<partintro>
<para>This chapter describes how to configure various aspects of a
NixOS machine through the configuration file
<filename>/etc/nixos/configuration.nix</filename>. As described in
<xref linkend="sec-changing-config" />, changes to this file only take
effect after you run <command>nixos-rebuild</command>.</para>
</partintro>
<xi:include href="config-syntax.xml" />
<xi:include href="package-mgmt.xml" />
<xi:include href="user-mgmt.xml" />
<xi:include href="file-systems.xml" />
<xi:include href="x-windows.xml" />
<xi:include href="xfce.xml" />
<xi:include href="networking.xml" />
<xi:include href="linux-kernel.xml" />
<xi:include href="../generated/modules.xml" xpointer="xpointer(//section[@id='modules']/*)" />
<title>Configuration</title>
<partintro>
<para>
This chapter describes how to configure various aspects of a NixOS machine
through the configuration file
<filename>/etc/nixos/configuration.nix</filename>. As described in
<xref linkend="sec-changing-config" />, changes to this file only take
effect after you run <command>nixos-rebuild</command>.
</para>
</partintro>
<xi:include href="config-syntax.xml" />
<xi:include href="package-mgmt.xml" />
<xi:include href="user-mgmt.xml" />
<xi:include href="file-systems.xml" />
<xi:include href="x-windows.xml" />
<xi:include href="xfce.xml" />
<xi:include href="networking.xml" />
<xi:include href="linux-kernel.xml" />
<xi:include href="../generated/modules.xml" xpointer="xpointer(//section[@id='modules']/*)" />
<!-- Apache; libvirtd virtualisation -->
</part>

125
nixos/doc/manual/configuration/customizing-packages.xml
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@ -3,53 +3,50 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-customising-packages">
<title>Customising Packages</title>
<title>Customising Packages</title>
<para>
Some packages in Nixpkgs have options to enable or disable optional
functionality or change other aspects of the package. For instance, the
Firefox wrapper package (which provides Firefox with a set of plugins such as
the Adobe Flash player) has an option to enable the Google Talk plugin. It
can be set in <filename>configuration.nix</filename> as follows: <filename>
nixpkgs.config.firefox.enableGoogleTalkPlugin = true; </filename>
</para>
<para>Some packages in Nixpkgs have options to enable or disable
optional functionality or change other aspects of the package. For
instance, the Firefox wrapper package (which provides Firefox with a
set of plugins such as the Adobe Flash player) has an option to enable
the Google Talk plugin. It can be set in
<filename>configuration.nix</filename> as follows:
<filename>
nixpkgs.config.firefox.enableGoogleTalkPlugin = true;
</filename>
</para>
<warning><para>Unfortunately, Nixpkgs currently lacks a way to query
available configuration options.</para></warning>
<para>Apart from high-level options, it’s possible to tweak a package
in almost arbitrary ways, such as changing or disabling dependencies
of a package. For instance, the Emacs package in Nixpkgs by default
has a dependency on GTK+ 2. If you want to build it against GTK+ 3,
you can specify that as follows:
<warning>
<para>
Unfortunately, Nixpkgs currently lacks a way to query available
configuration options.
</para>
</warning>
<para>
Apart from high-level options, it’s possible to tweak a package in almost
arbitrary ways, such as changing or disabling dependencies of a package. For
instance, the Emacs package in Nixpkgs by default has a dependency on GTK+ 2.
If you want to build it against GTK+ 3, you can specify that as follows:
<programlisting>
<xref linkend="opt-environment.systemPackages"/> = [ (pkgs.emacs.override { gtk = pkgs.gtk3; }) ];
</programlisting>
The function <varname>override</varname> performs the call to the Nix
function that produces Emacs, with the original arguments amended by the set
of arguments specified by you. So here the function argument
<varname>gtk</varname> gets the value <literal>pkgs.gtk3</literal>, causing
Emacs to depend on GTK+ 3. (The parentheses are necessary because in Nix,
function application binds more weakly than list construction, so without
them, <xref linkend="opt-environment.systemPackages"/> would be a list with
two elements.)
</para>
The function <varname>override</varname> performs the call to the Nix
function that produces Emacs, with the original arguments amended by
the set of arguments specified by you. So here the function argument
<varname>gtk</varname> gets the value <literal>pkgs.gtk3</literal>,
causing Emacs to depend on GTK+ 3. (The parentheses are necessary
because in Nix, function application binds more weakly than list
construction, so without them,
<xref linkend="opt-environment.systemPackages"/> would be a list with two
elements.)</para>
<para>Even greater customisation is possible using the function
<varname>overrideAttrs</varname>. While the
<varname>override</varname> mechanism above overrides the arguments of
a package function, <varname>overrideAttrs</varname> allows
changing the <emphasis>attributes</emphasis> passed to <literal>mkDerivation</literal>.
This permits changing any aspect of the package, such as the source code.
For instance, if you want to override the source code of Emacs, you
can say:
<para>
Even greater customisation is possible using the function
<varname>overrideAttrs</varname>. While the <varname>override</varname>
mechanism above overrides the arguments of a package function,
<varname>overrideAttrs</varname> allows changing the
<emphasis>attributes</emphasis> passed to <literal>mkDerivation</literal>.
This permits changing any aspect of the package, such as the source code. For
instance, if you want to override the source code of Emacs, you can say:
<programlisting>
<xref linkend="opt-environment.systemPackages"/> = [
(pkgs.emacs.overrideAttrs (oldAttrs: {
@ -58,36 +55,32 @@ can say:
}))
];
</programlisting>
Here, <varname>overrideAttrs</varname> takes the Nix derivation specified by
<varname>pkgs.emacs</varname> and produces a new derivation in which the
original’s <literal>name</literal> and <literal>src</literal> attribute
have been replaced by the given values by re-calling
<literal>stdenv.mkDerivation</literal>. The original attributes are
accessible via the function argument, which is conventionally named
<varname>oldAttrs</varname>.
</para>
Here, <varname>overrideAttrs</varname> takes the Nix derivation
specified by <varname>pkgs.emacs</varname> and produces a new
derivation in which the original’s <literal>name</literal> and
<literal>src</literal> attribute have been replaced by the given
values by re-calling <literal>stdenv.mkDerivation</literal>.
The original attributes are accessible via the function argument,
which is conventionally named <varname>oldAttrs</varname>.</para>
<para>The overrides shown above are not global. They do not affect
the original package; other packages in Nixpkgs continue to depend on
the original rather than the customised package. This means that if
another package in your system depends on the original package, you
end up with two instances of the package. If you want to have
everything depend on your customised instance, you can apply a
<emphasis>global</emphasis> override as follows:
<para>
The overrides shown above are not global. They do not affect the original
package; other packages in Nixpkgs continue to depend on the original rather
than the customised package. This means that if another package in your
system depends on the original package, you end up with two instances of the
package. If you want to have everything depend on your customised instance,
you can apply a <emphasis>global</emphasis> override as follows:
<screen>
nixpkgs.config.packageOverrides = pkgs:
{ emacs = pkgs.emacs.override { gtk = pkgs.gtk3; };
};
</screen>
The effect of this definition is essentially equivalent to modifying
the <literal>emacs</literal> attribute in the Nixpkgs source tree.
Any package in Nixpkgs that depends on <literal>emacs</literal> will
be passed your customised instance. (However, the value
<literal>pkgs.emacs</literal> in
<varname>nixpkgs.config.packageOverrides</varname> refers to the
original rather than overridden instance, to prevent an infinite
recursion.)</para>
The effect of this definition is essentially equivalent to modifying the
<literal>emacs</literal> attribute in the Nixpkgs source tree. Any package in
Nixpkgs that depends on <literal>emacs</literal> will be passed your
customised instance. (However, the value <literal>pkgs.emacs</literal> in
<varname>nixpkgs.config.packageOverrides</varname> refers to the original
rather than overridden instance, to prevent an infinite recursion.)
</para>
</section>

48
nixos/doc/manual/configuration/declarative-packages.xml
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@ -3,41 +3,41 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-declarative-package-mgmt">
<title>Declarative Package Management</title>
<title>Declarative Package Management</title>
<para>With declarative package management, you specify which packages
you want on your system by setting the option
<xref linkend="opt-environment.systemPackages"/>. For instance, adding the
following line to <filename>configuration.nix</filename> enables the
Mozilla Thunderbird email application:
<para>
With declarative package management, you specify which packages you want on
your system by setting the option
<xref linkend="opt-environment.systemPackages"/>. For instance, adding the
following line to <filename>configuration.nix</filename> enables the Mozilla
Thunderbird email application:
<programlisting>
<xref linkend="opt-environment.systemPackages"/> = [ pkgs.thunderbird ];
</programlisting>
The effect of this specification is that the Thunderbird package from Nixpkgs
will be built or downloaded as part of the system when you run
<command>nixos-rebuild switch</command>.
</para>
The effect of this specification is that the Thunderbird package from
Nixpkgs will be built or downloaded as part of the system when you run
<command>nixos-rebuild switch</command>.</para>
<para>You can get a list of the available packages as follows:
<para>
You can get a list of the available packages as follows:
<screen>
$ nix-env -qaP '*' --description
nixos.firefox firefox-23.0 Mozilla Firefox - the browser, reloaded
<replaceable>...</replaceable>
</screen>
The first column in the output is the <emphasis>attribute name</emphasis>,
such as <literal>nixos.thunderbird</literal>. (The <literal>nixos</literal>
prefix allows distinguishing between different channels that you might have.)
</para>
The first column in the output is the <emphasis>attribute
name</emphasis>, such as
<literal>nixos.thunderbird</literal>. (The
<literal>nixos</literal> prefix allows distinguishing between
different channels that you might have.)</para>
<para>
To “uninstall” a package, simply remove it from
<xref linkend="opt-environment.systemPackages"/> and run
<command>nixos-rebuild switch</command>.
</para>
<para>To “uninstall” a package, simply remove it from
<xref linkend="opt-environment.systemPackages"/> and run
<command>nixos-rebuild switch</command>.</para>
<xi:include href="customizing-packages.xml" />
<xi:include href="adding-custom-packages.xml" />
<xi:include href="customizing-packages.xml" />
<xi:include href="adding-custom-packages.xml" />
</section>

68
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@ -3,44 +3,44 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="ch-file-systems">
<title>File Systems</title>
<para>You can define file systems using the
<option>fileSystems</option> configuration option. For instance, the
following definition causes NixOS to mount the Ext4 file system on
device <filename>/dev/disk/by-label/data</filename> onto the mount
point <filename>/data</filename>:
<title>File Systems</title>
<para>
You can define file systems using the <option>fileSystems</option>
configuration option. For instance, the following definition causes NixOS to
mount the Ext4 file system on device
<filename>/dev/disk/by-label/data</filename> onto the mount point
<filename>/data</filename>:
<programlisting>
<xref linkend="opt-fileSystems"/>."/data" =
{ device = "/dev/disk/by-label/data";
fsType = "ext4";
};
</programlisting>
Mount points are created automatically if they don’t already exist.
For <option><link linkend="opt-fileSystems._name__.device">device</link></option>, it’s best to use the topology-independent
device aliases in <filename>/dev/disk/by-label</filename> and
<filename>/dev/disk/by-uuid</filename>, as these don’t change if the
topology changes (e.g. if a disk is moved to another IDE
controller).</para>
<para>You can usually omit the file system type
(<option><link linkend="opt-fileSystems._name__.fsType">fsType</link></option>), since <command>mount</command> can usually
detect the type and load the necessary kernel module automatically.
However, if the file system is needed at early boot (in the initial
ramdisk) and is not <literal>ext2</literal>, <literal>ext3</literal>
or <literal>ext4</literal>, then it’s best to specify
<option>fsType</option> to ensure that the kernel module is
available.</para>
<note><para>System startup will fail if any of the filesystems fails to mount,
dropping you to the emergency shell.
You can make a mount asynchronous and non-critical by adding
<literal><link linkend="opt-fileSystems._name__.options">options</link> = [ "nofail" ];</literal>.
</para></note>
<xi:include href="luks-file-systems.xml" />
Mount points are created automatically if they don’t already exist. For
<option><link linkend="opt-fileSystems._name__.device">device</link></option>,
it’s best to use the topology-independent device aliases in
<filename>/dev/disk/by-label</filename> and
<filename>/dev/disk/by-uuid</filename>, as these don’t change if the
topology changes (e.g. if a disk is moved to another IDE controller).
</para>
<para>
You can usually omit the file system type
(<option><link linkend="opt-fileSystems._name__.fsType">fsType</link></option>),
since <command>mount</command> can usually detect the type and load the
necessary kernel module automatically. However, if the file system is needed
at early boot (in the initial ramdisk) and is not <literal>ext2</literal>,
<literal>ext3</literal> or <literal>ext4</literal>, then it’s best to
specify <option>fsType</option> to ensure that the kernel module is
available.
</para>
<note>
<para>
System startup will fail if any of the filesystems fails to mount, dropping
you to the emergency shell. You can make a mount asynchronous and
non-critical by adding
<literal><link linkend="opt-fileSystems._name__.options">options</link> = [
"nofail" ];</literal>.
</para>
</note>
<xi:include href="luks-file-systems.xml" />
</chapter>

49
nixos/doc/manual/configuration/firewall.xml
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@ -3,49 +3,44 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-firewall">
<title>Firewall</title>
<title>Firewall</title>
<para>NixOS has a simple stateful firewall that blocks incoming
connections and other unexpected packets. The firewall applies to
both IPv4 and IPv6 traffic. It is enabled by default. It can be
disabled as follows:
<para>
NixOS has a simple stateful firewall that blocks incoming connections and
other unexpected packets. The firewall applies to both IPv4 and IPv6 traffic.
It is enabled by default. It can be disabled as follows:
<programlisting>
<xref linkend="opt-networking.firewall.enable"/> = false;
</programlisting>
If the firewall is enabled, you can open specific TCP ports to the
outside world:
If the firewall is enabled, you can open specific TCP ports to the outside
world:
<programlisting>
<xref linkend="opt-networking.firewall.allowedTCPPorts"/> = [ 80 443 ];
</programlisting>
Note that TCP port 22 (ssh) is opened automatically if the SSH daemon is
enabled (<option><xref linkend="opt-services.openssh.enable"/> =
true</option>). UDP ports can be opened through
<xref linkend="opt-networking.firewall.allowedUDPPorts"/>.
</para>
Note that TCP port 22 (ssh) is opened automatically if the SSH daemon
is enabled (<option><xref linkend="opt-services.openssh.enable"/> = true</option>). UDP
ports can be opened through
<xref linkend="opt-networking.firewall.allowedUDPPorts"/>.</para>
<para>To open ranges of TCP ports:
<para>
To open ranges of TCP ports:
<programlisting>
<xref linkend="opt-networking.firewall.allowedTCPPortRanges"/> = [
{ from = 4000; to = 4007; }
{ from = 8000; to = 8010; }
];
</programlisting>
Similarly, UDP port ranges can be opened through
<xref linkend="opt-networking.firewall.allowedUDPPortRanges"/>.
</para>
Similarly, UDP port ranges can be opened through
<xref linkend="opt-networking.firewall.allowedUDPPortRanges"/>.</para>
<para>Also of interest is
<para>
Also of interest is
<programlisting>
<xref linkend="opt-networking.firewall.allowPing"/> = true;
</programlisting>
to allow the machine to respond to ping requests. (ICMPv6 pings are
always allowed.)</para>
to allow the machine to respond to ping requests. (ICMPv6 pings are always
allowed.)
</para>
</section>

46
nixos/doc/manual/configuration/ipv4-config.xml
View File

@ -3,45 +3,41 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-ipv4">
<title>IPv4 Configuration</title>
<title>IPv4 Configuration</title>
<para>By default, NixOS uses DHCP (specifically,
<command>dhcpcd</command>) to automatically configure network
interfaces. However, you can configure an interface manually as
follows:
<para>
By default, NixOS uses DHCP (specifically, <command>dhcpcd</command>) to
automatically configure network interfaces. However, you can configure an
interface manually as follows:
<programlisting>
<link linkend="opt-networking.interfaces._name__.ipv4.addresses">networking.interfaces.eth0.ipv4.addresses</link> = [ {
address = "192.168.1.2";
prefixLength = 24;
} ];
</programlisting>
Typically you’ll also want to set a default gateway and set of name
servers:
Typically you’ll also want to set a default gateway and set of name
servers:
<programlisting>
<xref linkend="opt-networking.defaultGateway"/> = "192.168.1.1";
<xref linkend="opt-networking.nameservers"/> = [ "8.8.8.8" ];
</programlisting>
</para>
</para>
<note><para>Statically configured interfaces are set up by the systemd
service
<replaceable>interface-name</replaceable><literal>-cfg.service</literal>.
The default gateway and name server configuration is performed by
<literal>network-setup.service</literal>.</para></note>
<para>The host name is set using <xref linkend="opt-networking.hostName"/>:
<note>
<para>
Statically configured interfaces are set up by the systemd service
<replaceable>interface-name</replaceable><literal>-cfg.service</literal>.
The default gateway and name server configuration is performed by
<literal>network-setup.service</literal>.
</para>
</note>
<para>
The host name is set using <xref linkend="opt-networking.hostName"/>:
<programlisting>
<xref linkend="opt-networking.hostName"/> = "cartman";
</programlisting>
The default host name is <literal>nixos</literal>. Set it to the
empty string (<literal>""</literal>) to allow the DHCP server to
provide the host name.</para>
The default host name is <literal>nixos</literal>. Set it to the empty string
(<literal>""</literal>) to allow the DHCP server to provide the host name.
</para>
</section>

43
nixos/doc/manual/configuration/ipv6-config.xml
View File

@ -3,47 +3,48 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-ipv6">
<title>IPv6 Configuration</title>
<title>IPv6 Configuration</title>
<para>IPv6 is enabled by default. Stateless address autoconfiguration
is used to automatically assign IPv6 addresses to all interfaces. You
can disable IPv6 support globally by setting:
<para>
IPv6 is enabled by default. Stateless address autoconfiguration is used to
automatically assign IPv6 addresses to all interfaces. You can disable IPv6
support globally by setting:
<programlisting>
<xref linkend="opt-networking.enableIPv6"/> = false;
</programlisting></para>
<para>You can disable IPv6 on a single interface using a normal sysctl (in this
example, we use interface <varname>eth0</varname>):
</programlisting>
</para>
<para>
You can disable IPv6 on a single interface using a normal sysctl (in this
example, we use interface <varname>eth0</varname>):
<programlisting>
<xref linkend="opt-boot.kernel.sysctl"/>."net.ipv6.conf.eth0.disable_ipv6" = true;
</programlisting>
</para>
<para>As with IPv4 networking interfaces are automatically configured via
DHCPv6. You can configure an interface manually:
</para>
<para>
As with IPv4 networking interfaces are automatically configured via DHCPv6.
You can configure an interface manually:
<programlisting>
<link linkend="opt-networking.interfaces._name__.ipv6.addresses">networking.interfaces.eth0.ipv6.addresses</link> = [ {
address = "fe00:aa:bb:cc::2";
prefixLength = 64;
} ];
</programlisting>
</para>
<para>For configuring a gateway, optionally with explicitly specified interface:
</para>
<para>
For configuring a gateway, optionally with explicitly specified interface:
<programlisting>
<xref linkend="opt-networking.defaultGateway6"/> = {
address = "fe00::1";
interface = "enp0s3";
}
</programlisting>
</para>
<para>See <xref linkend='sec-ipv4' /> for similar examples and additional information.
</para>
</para>
<para>
See <xref linkend='sec-ipv4' /> for similar examples and additional
information.
</para>
</section>

93
nixos/doc/manual/configuration/linux-kernel.xml
View File

@ -3,29 +3,29 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-kernel-config">
<title>Linux Kernel</title>
<para>You can override the Linux kernel and associated packages using
the option <option>boot.kernelPackages</option>. For instance, this
selects the Linux 3.10 kernel:
<title>Linux Kernel</title>
<para>
You can override the Linux kernel and associated packages using the option
<option>boot.kernelPackages</option>. For instance, this selects the Linux
3.10 kernel:
<programlisting>
<xref linkend="opt-boot.kernelPackages"/> = pkgs.linuxPackages_3_10;
</programlisting>
Note that this not only replaces the kernel, but also packages that
are specific to the kernel version, such as the NVIDIA video drivers.
This ensures that driver packages are consistent with the
kernel.</para>
<para>The default Linux kernel configuration should be fine for most users. You can see the configuration of your current kernel with the following command:
Note that this not only replaces the kernel, but also packages that are
specific to the kernel version, such as the NVIDIA video drivers. This
ensures that driver packages are consistent with the kernel.
</para>
<para>
The default Linux kernel configuration should be fine for most users. You can
see the configuration of your current kernel with the following command:
<programlisting>
zcat /proc/config.gz
</programlisting>
If you want to change the kernel configuration, you can use the
<option>packageOverrides</option> feature (see <xref
linkend="sec-customising-packages" />). For instance, to enable
support for the kernel debugger KGDB:
If you want to change the kernel configuration, you can use the
<option>packageOverrides</option> feature (see
<xref
linkend="sec-customising-packages" />). For instance, to enable support
for the kernel debugger KGDB:
<programlisting>
nixpkgs.config.packageOverrides = pkgs:
{ linux_3_4 = pkgs.linux_3_4.override {
@ -36,47 +36,46 @@ nixpkgs.config.packageOverrides = pkgs:
};
};
</programlisting>
<varname>extraConfig</varname> takes a list of Linux kernel
configuration options, one per line. The name of the option should
not include the prefix <literal>CONFIG_</literal>. The option value
is typically <literal>y</literal>, <literal>n</literal> or
<literal>m</literal> (to build something as a kernel module).</para>
<para>Kernel modules for hardware devices are generally loaded
automatically by <command>udev</command>. You can force a module to
be loaded via <xref linkend="opt-boot.kernelModules"/>, e.g.
<varname>extraConfig</varname> takes a list of Linux kernel configuration
options, one per line. The name of the option should not include the prefix
<literal>CONFIG_</literal>. The option value is typically
<literal>y</literal>, <literal>n</literal> or <literal>m</literal> (to build
something as a kernel module).
</para>
<para>
Kernel modules for hardware devices are generally loaded automatically by
<command>udev</command>. You can force a module to be loaded via
<xref linkend="opt-boot.kernelModules"/>, e.g.
<programlisting>
<xref linkend="opt-boot.kernelModules"/> = [ "fuse" "kvm-intel" "coretemp" ];
</programlisting>
If the module is required early during the boot (e.g. to mount the
root file system), you can use
<xref linkend="opt-boot.initrd.extraKernelModules"/>:
If the module is required early during the boot (e.g. to mount the root file
system), you can use <xref linkend="opt-boot.initrd.extraKernelModules"/>:
<programlisting>
<xref linkend="opt-boot.initrd.extraKernelModules"/> = [ "cifs" ];
</programlisting>
This causes the specified modules and their dependencies to be added
to the initial ramdisk.</para>
<para>Kernel runtime parameters can be set through
<xref linkend="opt-boot.kernel.sysctl"/>, e.g.
This causes the specified modules and their dependencies to be added to the
initial ramdisk.
</para>
<para>
Kernel runtime parameters can be set through
<xref linkend="opt-boot.kernel.sysctl"/>, e.g.
<programlisting>
<xref linkend="opt-boot.kernel.sysctl"/>."net.ipv4.tcp_keepalive_time" = 120;
</programlisting>
sets the kernel’s TCP keepalive time to 120 seconds. To see the
available parameters, run <command>sysctl -a</command>.</para>
<section>
sets the kernel’s TCP keepalive time to 120 seconds. To see the available
parameters, run <command>sysctl -a</command>.
</para>
<section>
<title>Developing kernel modules</title>
<para>When developing kernel modules it's often convenient to run
edit-compile-run loop as quickly as possible.
See below snippet as an example of developing <literal>mellanox</literal>
drivers.
<para>
When developing kernel modules it's often convenient to run edit-compile-run
loop as quickly as possible. See below snippet as an example of developing
<literal>mellanox</literal> drivers.
</para>
<screen><![CDATA[
<screen><![CDATA[
$ nix-build '<nixpkgs>' -A linuxPackages.kernel.dev
$ nix-shell '<nixpkgs>' -A linuxPackages.kernel
$ unpackPhase
@ -84,7 +83,5 @@ $ cd linux-*
$ make -C $dev/lib/modules/*/build M=$(pwd)/drivers/net/ethernet/mellanox modules
# insmod ./drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.ko
]]></screen>
</section>
</section>
</chapter>

30
nixos/doc/manual/configuration/luks-file-systems.xml
View File

@ -3,14 +3,13 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-luks-file-systems">
<title>LUKS-Encrypted File Systems</title>
<title>LUKS-Encrypted File Systems</title>
<para>NixOS supports file systems that are encrypted using
<emphasis>LUKS</emphasis> (Linux Unified Key Setup). For example,
here is how you create an encrypted Ext4 file system on the device
<filename>/dev/disk/by-uuid/3f6b0024-3a44-4fde-a43a-767b872abe5d</filename>:
<para>
NixOS supports file systems that are encrypted using
<emphasis>LUKS</emphasis> (Linux Unified Key Setup). For example, here is how
you create an encrypted Ext4 file system on the device
<filename>/dev/disk/by-uuid/3f6b0024-3a44-4fde-a43a-767b872abe5d</filename>:
<screen>
# cryptsetup luksFormat /dev/disk/by-uuid/3f6b0024-3a44-4fde-a43a-767b872abe5d
@ -27,20 +26,15 @@ Enter passphrase for /dev/disk/by-uuid/3f6b0024-3a44-4fde-a43a-767b872abe5d: ***
# mkfs.ext4 /dev/mapper/crypted
</screen>
To ensure that this file system is automatically mounted at boot time
as <filename>/</filename>, add the following to
<filename>configuration.nix</filename>:
To ensure that this file system is automatically mounted at boot time as
<filename>/</filename>, add the following to
<filename>configuration.nix</filename>:
<programlisting>
<link linkend="opt-boot.initrd.luks.devices._name__.device">boot.initrd.luks.devices.crypted.device</link> = "/dev/disk/by-uuid/3f6b0024-3a44-4fde-a43a-767b872abe5d";
<xref linkend="opt-fileSystems"/>."/".device = "/dev/mapper/crypted";
</programlisting>
Should grub be used as bootloader, and <filename>/boot</filename> is located
on an encrypted partition, it is necessary to add the following grub option:
Should grub be used as bootloader, and <filename>/boot</filename> is located
on an encrypted partition, it is necessary to add the following grub option:
<programlisting><xref linkend="opt-boot.loader.grub.enableCryptodisk"/> = true;</programlisting>
</para>
</para>
</section>

140
nixos/doc/manual/configuration/modularity.xml
View File

@ -3,21 +3,21 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-modularity">
<title>Modularity</title>
<title>Modularity</title>
<para>The NixOS configuration mechanism is modular. If your
<filename>configuration.nix</filename> becomes too big, you can split
it into multiple files. Likewise, if you have multiple NixOS
configurations (e.g. for different computers) with some commonality,
you can move the common configuration into a shared file.</para>
<para>Modules have exactly the same syntax as
<filename>configuration.nix</filename>. In fact,
<filename>configuration.nix</filename> is itself a module. You can
use other modules by including them from
<filename>configuration.nix</filename>, e.g.:
<para>
The NixOS configuration mechanism is modular. If your
<filename>configuration.nix</filename> becomes too big, you can split it into
multiple files. Likewise, if you have multiple NixOS configurations (e.g. for
different computers) with some commonality, you can move the common
configuration into a shared file.
</para>
<para>
Modules have exactly the same syntax as
<filename>configuration.nix</filename>. In fact,
<filename>configuration.nix</filename> is itself a module. You can use other
modules by including them from <filename>configuration.nix</filename>, e.g.:
<programlisting>
{ config, pkgs, ... }:
@ -27,11 +27,9 @@ use other modules by including them from
<replaceable>...</replaceable>
}
</programlisting>
Here, we include two modules from the same directory,
<filename>vpn.nix</filename> and <filename>kde.nix</filename>. The
latter might look like this:
Here, we include two modules from the same directory,
<filename>vpn.nix</filename> and <filename>kde.nix</filename>. The latter
might look like this:
<programlisting>
{ config, pkgs, ... }:
@ -40,59 +38,55 @@ latter might look like this:
<xref linkend="opt-services.xserver.desktopManager.plasma5.enable"/> = true;
}
</programlisting>
Note that both <filename>configuration.nix</filename> and
<filename>kde.nix</filename> define the option
<xref linkend="opt-environment.systemPackages"/>. When multiple modules
define an option, NixOS will try to <emphasis>merge</emphasis> the
definitions. In the case of
<xref linkend="opt-environment.systemPackages"/>, that’s easy: the lists of
packages can simply be concatenated. The value in
<filename>configuration.nix</filename> is merged last, so for
list-type options, it will appear at the end of the merged list. If
you want it to appear first, you can use <varname>mkBefore</varname>:
Note that both <filename>configuration.nix</filename> and
<filename>kde.nix</filename> define the option
<xref linkend="opt-environment.systemPackages"/>. When multiple modules
define an option, NixOS will try to <emphasis>merge</emphasis> the
definitions. In the case of <xref linkend="opt-environment.systemPackages"/>,
that’s easy: the lists of packages can simply be concatenated. The value in
<filename>configuration.nix</filename> is merged last, so for list-type
options, it will appear at the end of the merged list. If you want it to
appear first, you can use <varname>mkBefore</varname>:
<programlisting>
<xref linkend="opt-boot.kernelModules"/> = mkBefore [ "kvm-intel" ];
</programlisting>
This causes the <literal>kvm-intel</literal> kernel module to be loaded
before any other kernel modules.
</para>
This causes the <literal>kvm-intel</literal> kernel module to be
loaded before any other kernel modules.</para>
<para>For other types of options, a merge may not be possible. For
instance, if two modules define
<xref linkend="opt-services.httpd.adminAddr"/>,
<command>nixos-rebuild</command> will give an error:
<para>
For other types of options, a merge may not be possible. For instance, if two
modules define <xref linkend="opt-services.httpd.adminAddr"/>,
<command>nixos-rebuild</command> will give an error:
<screen>
The unique option `services.httpd.adminAddr' is defined multiple times, in `/etc/nixos/httpd.nix' and `/etc/nixos/configuration.nix'.
</screen>
When that happens, it’s possible to force one definition take
precedence over the others:
When that happens, it’s possible to force one definition take precedence
over the others:
<programlisting>
<xref linkend="opt-services.httpd.adminAddr"/> = pkgs.lib.mkForce "bob@example.org";
</programlisting>
</para>
</para>
<para>When using multiple modules, you may need to access
configuration values defined in other modules. This is what the
<varname>config</varname> function argument is for: it contains the
complete, merged system configuration. That is,
<varname>config</varname> is the result of combining the
configurations returned by every module<footnote><para>If you’re
wondering how it’s possible that the (indirect)
<emphasis>result</emphasis> of a function is passed as an
<emphasis>input</emphasis> to that same function: that’s because Nix
is a “lazy” language — it only computes values when they are needed.
This works as long as no individual configuration value depends on
itself.</para></footnote>. For example, here is a module that adds
some packages to <xref linkend="opt-environment.systemPackages"/> only if
<xref linkend="opt-services.xserver.enable"/> is set to
<literal>true</literal> somewhere else:
<para>
When using multiple modules, you may need to access configuration values
defined in other modules. This is what the <varname>config</varname> function
argument is for: it contains the complete, merged system configuration. That
is, <varname>config</varname> is the result of combining the configurations
returned by every module
<footnote>
<para>
If you’re wondering how it’s possible that the (indirect)
<emphasis>result</emphasis> of a function is passed as an
<emphasis>input</emphasis> to that same function: that’s because Nix is a
“lazy” language — it only computes values when they are needed. This
works as long as no individual configuration value depends on itself.
</para>
</footnote>
. For example, here is a module that adds some packages to
<xref linkend="opt-environment.systemPackages"/> only if
<xref linkend="opt-services.xserver.enable"/> is set to
<literal>true</literal> somewhere else:
<programlisting>
{ config, pkgs, ... }:
@ -105,13 +99,12 @@ some packages to <xref linkend="opt-environment.systemPackages"/> only if
[ ];
}
</programlisting>
</para>
</para>
<para>With multiple modules, it may not be obvious what the final
value of a configuration option is. The command
<option>nixos-option</option> allows you to find out:
<para>
With multiple modules, it may not be obvious what the final value of a
configuration option is. The command <option>nixos-option</option> allows you
to find out:
<screen>
$ nixos-option <xref linkend="opt-services.xserver.enable"/>
true
@ -119,14 +112,11 @@ true
$ nixos-option <xref linkend="opt-boot.kernelModules"/>
[ "tun" "ipv6" "loop" <replaceable>...</replaceable> ]
</screen>
Interactive exploration of the configuration is possible using
<command
Interactive exploration of the configuration is possible using
<command
xlink:href="https://github.com/edolstra/nix-repl">nix-repl</command>,
a read-eval-print loop for Nix expressions. It’s not installed by
default; run <literal>nix-env -i nix-repl</literal> to get it. A
typical use:
a read-eval-print loop for Nix expressions. It’s not installed by default;
run <literal>nix-env -i nix-repl</literal> to get it. A typical use:
<screen>
$ nix-repl '&lt;nixpkgs/nixos>'
@ -136,7 +126,5 @@ nix-repl> config.<xref linkend="opt-networking.hostName"/>
nix-repl> map (x: x.hostName) config.<xref linkend="opt-services.httpd.virtualHosts"/>
[ "example.org" "example.gov" ]
</screen>
</para>
</para>
</section>

53
nixos/doc/manual/configuration/network-manager.xml
View File

@ -3,39 +3,42 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-networkmanager">
<title>NetworkManager</title>
<title>NetworkManager</title>
<para>To facilitate network configuration, some desktop environments
use NetworkManager. You can enable NetworkManager by setting:
<para>
To facilitate network configuration, some desktop environments use
NetworkManager. You can enable NetworkManager by setting:
<programlisting>
<xref linkend="opt-networking.networkmanager.enable"/> = true;
</programlisting>
some desktop managers (e.g., GNOME) enable NetworkManager automatically for
you.
</para>
some desktop managers (e.g., GNOME) enable NetworkManager
automatically for you.</para>
<para>All users that should have permission to change network settings must
belong to the <code>networkmanager</code> group:
<para>
All users that should have permission to change network settings must belong
to the <code>networkmanager</code> group:
<programlisting>
<link linkend="opt-users.users._name__.extraGroups">users.extraUsers.youruser.extraGroups</link> = [ "networkmanager" ];
</programlisting>
</para>
</para>
<para>NetworkManager is controlled using either <command>nmcli</command> or
<command>nmtui</command> (curses-based terminal user interface). See their
manual pages for details on their usage. Some desktop environments (GNOME, KDE)
have their own configuration tools for NetworkManager. On XFCE, there is no
configuration tool for NetworkManager by default: by adding
<code>networkmanagerapplet</code> to the list of system packages, the graphical
applet will be installed and will launch automatically when XFCE is starting
(and will show in the status tray).</para>
<note><para><code>networking.networkmanager</code> and
<code>networking.wireless</code> (WPA Supplicant) cannot be enabled at the same
time: you can still connect to the wireless networks using
NetworkManager.</para></note>
<para>
NetworkManager is controlled using either <command>nmcli</command> or
<command>nmtui</command> (curses-based terminal user interface). See their
manual pages for details on their usage. Some desktop environments (GNOME,
KDE) have their own configuration tools for NetworkManager. On XFCE, there is
no configuration tool for NetworkManager by default: by adding
<code>networkmanagerapplet</code> to the list of system packages, the
graphical applet will be installed and will launch automatically when XFCE is
starting (and will show in the status tray).
</para>
<note>
<para>
<code>networking.networkmanager</code> and <code>networking.wireless</code>
(WPA Supplicant) cannot be enabled at the same time: you can still connect
to the wireless networks using NetworkManager.
</para>
</note>
</section>

27
nixos/doc/manual/configuration/networking.xml
View File

@ -3,20 +3,17 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-networking">
<title>Networking</title>
<para>This section describes how to configure networking components on
your NixOS machine.</para>
<xi:include href="network-manager.xml" />
<xi:include href="ssh.xml" />
<xi:include href="ipv4-config.xml" />
<xi:include href="ipv6-config.xml" />
<xi:include href="firewall.xml" />
<xi:include href="wireless.xml" />
<xi:include href="ad-hoc-network-config.xml" />
<title>Networking</title>
<para>
This section describes how to configure networking components on your NixOS
machine.
</para>
<xi:include href="network-manager.xml" />
<xi:include href="ssh.xml" />
<xi:include href="ipv4-config.xml" />
<xi:include href="ipv6-config.xml" />
<xi:include href="firewall.xml" />
<xi:include href="wireless.xml" />
<xi:include href="ad-hoc-network-config.xml" />
<!-- TODO: OpenVPN, NAT -->
</chapter>

53
nixos/doc/manual/configuration/package-mgmt.xml
View File

@ -3,32 +3,29 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-package-management">
<title>Package Management</title>
<para>This section describes how to add additional packages to your
system. NixOS has two distinct styles of package management:
<itemizedlist>
<listitem><para><emphasis>Declarative</emphasis>, where you declare
what packages you want in your
<filename>configuration.nix</filename>. Every time you run
<command>nixos-rebuild</command>, NixOS will ensure that you get a
consistent set of binaries corresponding to your
specification.</para></listitem>
<listitem><para><emphasis>Ad hoc</emphasis>, where you install,
upgrade and uninstall packages via the <command>nix-env</command>
command. This style allows mixing packages from different Nixpkgs
versions. It’s the only choice for non-root
users.</para></listitem>
</itemizedlist>
</para>
<xi:include href="declarative-packages.xml" />
<xi:include href="ad-hoc-packages.xml" />
<title>Package Management</title>
<para>
This section describes how to add additional packages to your system. NixOS
has two distinct styles of package management:
<itemizedlist>
<listitem>
<para>
<emphasis>Declarative</emphasis>, where you declare what packages you want
in your <filename>configuration.nix</filename>. Every time you run
<command>nixos-rebuild</command>, NixOS will ensure that you get a
consistent set of binaries corresponding to your specification.
</para>
</listitem>
<listitem>
<para>
<emphasis>Ad hoc</emphasis>, where you install, upgrade and uninstall
packages via the <command>nix-env</command> command. This style allows
mixing packages from different Nixpkgs versions. It’s the only choice
for non-root users.
</para>
</listitem>
</itemizedlist>
</para>
<xi:include href="declarative-packages.xml" />
<xi:include href="ad-hoc-packages.xml" />
</chapter>

27
nixos/doc/manual/configuration/ssh.xml
View File

@ -3,30 +3,25 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-ssh">
<title>Secure Shell Access</title>
<title>Secure Shell Access</title>
<para>Secure shell (SSH) access to your machine can be enabled by
setting:
<para>
Secure shell (SSH) access to your machine can be enabled by setting:
<programlisting>
<xref linkend="opt-services.openssh.enable"/> = true;
</programlisting>
By default, root logins using a password are disallowed. They can be disabled
entirely by setting <xref linkend="opt-services.openssh.permitRootLogin"/> to
<literal>"no"</literal>.
</para>
By default, root logins using a password are disallowed. They can be
disabled entirely by setting
<xref linkend="opt-services.openssh.permitRootLogin"/> to
<literal>"no"</literal>.</para>
<para>You can declaratively specify authorised RSA/DSA public keys for
a user as follows:
<para>
You can declaratively specify authorised RSA/DSA public keys for a user as
follows:
<!-- FIXME: this might not work if the user is unmanaged. -->
<programlisting>
<link linkend="opt-users.users._name__.openssh.authorizedKeys.keys">users.extraUsers.alice.openssh.authorizedKeys.keys</link> =
[ "ssh-dss AAAAB3NzaC1kc3MAAACBAPIkGWVEt4..." ];
</programlisting>
</para>
</para>
</section>

369
nixos/doc/manual/configuration/summary.xml
View File

@ -3,190 +3,225 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-nix-syntax-summary">
<title>Syntax Summary</title>
<title>Syntax Summary</title>
<para>Below is a summary of the most important syntactic constructs in
the Nix expression language. It’s not complete. In particular, there
are many other built-in functions. See the <link
<para>
Below is a summary of the most important syntactic constructs in the Nix
expression language. It’s not complete. In particular, there are many other
built-in functions. See the
<link
xlink:href="http://nixos.org/nix/manual/#chap-writing-nix-expressions">Nix
manual</link> for the rest.</para>
manual</link> for the rest.
</para>
<informaltable frame='none'>
<informaltable frame='none'>
<tgroup cols='2'>
<colspec colname='c1' rowsep='1' colsep='1' />
<colspec colname='c2' rowsep='1' />
<thead>
<row>
<entry>Example</entry>
<entry>Description</entry>
</row>
</thead>
<tbody>
<row>
<entry namest="c1" nameend="c2"><emphasis>Basic values</emphasis></entry>
</row>
<row>
<entry><literal>"Hello world"</literal></entry>
<entry>A string</entry>
</row>
<row>
<entry><literal>"${pkgs.bash}/bin/sh"</literal></entry>
<entry>A string containing an expression (expands to <literal>"/nix/store/<replaceable>hash</replaceable>-bash-<replaceable>version</replaceable>/bin/sh"</literal>)</entry>
</row>
<row>
<entry><literal>true</literal>, <literal>false</literal></entry>
<entry>Booleans</entry>
</row>
<row>
<entry><literal>123</literal></entry>
<entry>An integer</entry>
</row>
<row>
<entry><literal>./foo.png</literal></entry>
<entry>A path (relative to the containing Nix expression)</entry>
</row>
<row>
<entry namest="c1" nameend="c2"><emphasis>Compound values</emphasis></entry>
</row>
<row>
<entry><literal>{ x = 1; y = 2; }</literal></entry>
<entry>A set with attributes named <literal>x</literal> and <literal>y</literal></entry>
</row>
<row>
<entry><literal>{ foo.bar = 1; }</literal></entry>
<entry>A nested set, equivalent to <literal>{ foo = { bar = 1; }; }</literal></entry>
</row>
<row>
<entry><literal>rec { x = "foo"; y = x + "bar"; }</literal></entry>
<entry>A recursive set, equivalent to <literal>{ x = "foo"; y = "foobar"; }</literal></entry>
</row>
<row>
<entry><literal>[ "foo" "bar" ]</literal></entry>
<entry>A list with two elements</entry>
</row>
<row>
<entry namest="c1" nameend="c2"><emphasis>Operators</emphasis></entry>
</row>
<row>
<entry><literal>"foo" + "bar"</literal></entry>
<entry>String concatenation</entry>
</row>
<row>
<entry><literal>1 + 2</literal></entry>
<entry>Integer addition</entry>
</row>
<row>
<entry><literal>"foo" == "f" + "oo"</literal></entry>
<entry>Equality test (evaluates to <literal>true</literal>)</entry>
</row>
<row>
<entry><literal>"foo" != "bar"</literal></entry>
<entry>Inequality test (evaluates to <literal>true</literal>)</entry>
</row>
<row>
<entry><literal>!true</literal></entry>
<entry>Boolean negation</entry>
</row>
<row>
<entry><literal>{ x = 1; y = 2; }.x</literal></entry>
<entry>Attribute selection (evaluates to <literal>1</literal>)</entry>
</row>
<row>
<entry><literal>{ x = 1; y = 2; }.z or 3</literal></entry>
<entry>Attribute selection with default (evaluates to <literal>3</literal>)</entry>
</row>
<row>
<entry><literal>{ x = 1; y = 2; } // { z = 3; }</literal></entry>
<entry>Merge two sets (attributes in the right-hand set taking precedence)</entry>
</row>
<row>
<entry namest="c1" nameend="c2"><emphasis>Control structures</emphasis></entry>
</row>
<row>
<entry><literal>if 1 + 1 == 2 then "yes!" else "no!"</literal></entry>
<entry>Conditional expression</entry>
</row>
<row>
<entry><literal>assert 1 + 1 == 2; "yes!"</literal></entry>
<entry>Assertion check (evaluates to <literal>"yes!"</literal>). See <xref
<colspec colname='c1' rowsep='1' colsep='1' />
<colspec colname='c2' rowsep='1' />
<thead>
<row>
<entry>Example</entry>
<entry>Description</entry>
</row>
</thead>
<tbody>
<row>
<entry namest="c1" nameend="c2"><emphasis>Basic values</emphasis>
</entry>
</row>
<row>
<entry><literal>"Hello world"</literal>
</entry>
<entry>A string</entry>
</row>
<row>
<entry><literal>"${pkgs.bash}/bin/sh"</literal>
</entry>
<entry>A string containing an expression (expands to <literal>"/nix/store/<replaceable>hash</replaceable>-bash-<replaceable>version</replaceable>/bin/sh"</literal>)</entry>
</row>
<row>
<entry><literal>true</literal>, <literal>false</literal>
</entry>
<entry>Booleans</entry>
</row>
<row>
<entry><literal>123</literal>
</entry>
<entry>An integer</entry>
</row>
<row>
<entry><literal>./foo.png</literal>
</entry>
<entry>A path (relative to the containing Nix expression)</entry>
</row>
<row>
<entry namest="c1" nameend="c2"><emphasis>Compound values</emphasis>
</entry>
</row>
<row>
<entry><literal>{ x = 1; y = 2; }</literal>
</entry>
<entry>A set with attributes named <literal>x</literal> and <literal>y</literal>
</entry>
</row>
<row>
<entry><literal>{ foo.bar = 1; }</literal>
</entry>
<entry>A nested set, equivalent to <literal>{ foo = { bar = 1; }; }</literal>
</entry>
</row>
<row>
<entry><literal>rec { x = "foo"; y = x + "bar"; }</literal>
</entry>
<entry>A recursive set, equivalent to <literal>{ x = "foo"; y = "foobar"; }</literal>
</entry>
</row>
<row>
<entry><literal>[ "foo" "bar" ]</literal>
</entry>
<entry>A list with two elements</entry>
</row>
<row>
<entry namest="c1" nameend="c2"><emphasis>Operators</emphasis>
</entry>
</row>
<row>
<entry><literal>"foo" + "bar"</literal>
</entry>
<entry>String concatenation</entry>
</row>
<row>
<entry><literal>1 + 2</literal>
</entry>
<entry>Integer addition</entry>
</row>
<row>
<entry><literal>"foo" == "f" + "oo"</literal>
</entry>
<entry>Equality test (evaluates to <literal>true</literal>)</entry>
</row>
<row>
<entry><literal>"foo" != "bar"</literal>
</entry>
<entry>Inequality test (evaluates to <literal>true</literal>)</entry>
</row>
<row>
<entry><literal>!true</literal>
</entry>
<entry>Boolean negation</entry>
</row>
<row>
<entry><literal>{ x = 1; y = 2; }.x</literal>
</entry>
<entry>Attribute selection (evaluates to <literal>1</literal>)</entry>
</row>
<row>
<entry><literal>{ x = 1; y = 2; }.z or 3</literal>
</entry>
<entry>Attribute selection with default (evaluates to <literal>3</literal>)</entry>
</row>
<row>
<entry><literal>{ x = 1; y = 2; } // { z = 3; }</literal>
</entry>
<entry>Merge two sets (attributes in the right-hand set taking precedence)</entry>
</row>
<row>
<entry namest="c1" nameend="c2"><emphasis>Control structures</emphasis>
</entry>
</row>
<row>
<entry><literal>if 1 + 1 == 2 then "yes!" else "no!"</literal>
</entry>
<entry>Conditional expression</entry>
</row>
<row>
<entry><literal>assert 1 + 1 == 2; "yes!"</literal>
</entry>
<entry>Assertion check (evaluates to <literal>"yes!"</literal>). See <xref
linkend="sec-assertions"/> for using assertions in modules</entry>
</row>
<row>
<entry><literal>let x = "foo"; y = "bar"; in x + y</literal></entry>
<entry>Variable definition</entry>
</row>
<row>
<entry><literal>with pkgs.lib; head [ 1 2 3 ]</literal></entry>
<entry>Add all attributes from the given set to the scope
</row>
<row>
<entry><literal>let x = "foo"; y = "bar"; in x + y</literal>
</entry>
<entry>Variable definition</entry>
</row>
<row>
<entry><literal>with pkgs.lib; head [ 1 2 3 ]</literal>
</entry>
<entry>Add all attributes from the given set to the scope
(evaluates to <literal>1</literal>)</entry>
</row>
<row>
<entry namest="c1" nameend="c2"><emphasis>Functions (lambdas)</emphasis></entry>
</row>
<row>
<entry><literal>x: x + 1</literal></entry>
<entry>A function that expects an integer and returns it increased by 1</entry>
</row>
<row>
<entry><literal>(x: x + 1) 100</literal></entry>
<entry>A function call (evaluates to 101)</entry>
</row>
<row>
<entry><literal>let inc = x: x + 1; in inc (inc (inc 100))</literal></entry>
<entry>A function bound to a variable and subsequently called by name (evaluates to 103)</entry>
</row>
<row>
<entry><literal>{ x, y }: x + y</literal></entry>
<entry>A function that expects a set with required attributes
</row>
<row>
<entry namest="c1" nameend="c2"><emphasis>Functions (lambdas)</emphasis>
</entry>
</row>
<row>
<entry><literal>x: x + 1</literal>
</entry>
<entry>A function that expects an integer and returns it increased by 1</entry>
</row>
<row>
<entry><literal>(x: x + 1) 100</literal>
</entry>
<entry>A function call (evaluates to 101)</entry>
</row>
<row>
<entry><literal>let inc = x: x + 1; in inc (inc (inc 100))</literal>
</entry>
<entry>A function bound to a variable and subsequently called by name (evaluates to 103)</entry>
</row>
<row>
<entry><literal>{ x, y }: x + y</literal>
</entry>
<entry>A function that expects a set with required attributes
<literal>x</literal> and <literal>y</literal> and concatenates
them</entry>
</row>
<row>
<entry><literal>{ x, y ? "bar" }: x + y</literal></entry>
<entry>A function that expects a set with required attribute
</row>
<row>
<entry><literal>{ x, y ? "bar" }: x + y</literal>
</entry>
<entry>A function that expects a set with required attribute
<literal>x</literal> and optional <literal>y</literal>, using
<literal>"bar"</literal> as default value for
<literal>y</literal></entry>
</row>
<row>
<entry><literal>{ x, y, ... }: x + y</literal></entry>
<entry>A function that expects a set with required attributes
<literal>y</literal>
</entry>
</row>
<row>
<entry><literal>{ x, y, ... }: x + y</literal>
</entry>
<entry>A function that expects a set with required attributes
<literal>x</literal> and <literal>y</literal> and ignores any
other attributes</entry>
</row>
<row>
<entry><literal>{ x, y } @ args: x + y</literal></entry>
<entry>A function that expects a set with required attributes
</row>
<row>
<entry><literal>{ x, y } @ args: x + y</literal>
</entry>
<entry>A function that expects a set with required attributes
<literal>x</literal> and <literal>y</literal>, and binds the
whole set to <literal>args</literal></entry>
</row>
<row>
<entry namest="c1" nameend="c2"><emphasis>Built-in functions</emphasis></entry>
</row>
<row>
<entry><literal>import ./foo.nix</literal></entry>
<entry>Load and return Nix expression in given file</entry>
</row>
<row>
<entry><literal>map (x: x + x) [ 1 2 3 ]</literal></entry>
<entry>Apply a function to every element of a list (evaluates to <literal>[ 2 4 6 ]</literal>)</entry>
</row>
<!--
whole set to <literal>args</literal>
</entry>
</row>
<row>
<entry namest="c1" nameend="c2"><emphasis>Built-in functions</emphasis>
</entry>
</row>
<row>
<entry><literal>import ./foo.nix</literal>
</entry>
<entry>Load and return Nix expression in given file</entry>
</row>
<row>
<entry><literal>map (x: x + x) [ 1 2 3 ]</literal>
</entry>
<entry>Apply a function to every element of a list (evaluates to <literal>[ 2 4 6 ]</literal>)</entry>
</row>
<!--
<row>
<entry><literal>throw "Urgh"</literal></entry>
<entry>Raise an error condition</entry>
</row>
-->
</tbody>
</tbody>
</tgroup>
</informaltable>
</informaltable>
</section>

124
nixos/doc/manual/configuration/user-mgmt.xml
View File

@ -3,14 +3,12 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-user-management">
<title>User Management</title>
<para>NixOS supports both declarative and imperative styles of user
management. In the declarative style, users are specified in
<filename>configuration.nix</filename>. For instance, the following
states that a user account named <literal>alice</literal> shall exist:
<title>User Management</title>
<para>
NixOS supports both declarative and imperative styles of user management. In
the declarative style, users are specified in
<filename>configuration.nix</filename>. For instance, the following states
that a user account named <literal>alice</literal> shall exist:
<programlisting>
<xref linkend="opt-users.users"/>.alice = {
<link linkend="opt-users.users._name__.isNormalUser">isNormalUser</link> = true;
@ -20,81 +18,71 @@ states that a user account named <literal>alice</literal> shall exist:
<link linkend="opt-users.users._name__.openssh.authorizedKeys.keys">openssh.authorizedKeys.keys</link> = [ "ssh-dss AAAAB3Nza... alice@foobar" ];
};
</programlisting>
Note that <literal>alice</literal> is a member of the
<literal>wheel</literal> and <literal>networkmanager</literal> groups,
which allows her to use <command>sudo</command> to execute commands as
<literal>root</literal> and to configure the network, respectively.
Also note the SSH public key that allows remote logins with the
corresponding private key. Users created in this way do not have a
password by default, so they cannot log in via mechanisms that require
a password. However, you can use the <command>passwd</command> program
to set a password, which is retained across invocations of
<command>nixos-rebuild</command>.</para>
<para>If you set <xref linkend="opt-users.mutableUsers"/> to false, then the contents of
<literal>/etc/passwd</literal> and <literal>/etc/group</literal> will be congruent to
your NixOS configuration. For instance, if you remove a user from <xref linkend="opt-users.users"/>
and run nixos-rebuild, the user account will cease to exist. Also, imperative commands for managing users
and groups, such as useradd, are no longer available. Passwords may still be
assigned by setting the user's <link linkend="opt-users.users._name__.hashedPassword">hashedPassword</link>
option. A hashed password can be generated using <command>mkpasswd -m sha-512</command>
after installing the <literal>mkpasswd</literal> package.</para>
<para>A user ID (uid) is assigned automatically. You can also specify
a uid manually by adding
Note that <literal>alice</literal> is a member of the
<literal>wheel</literal> and <literal>networkmanager</literal> groups, which
allows her to use <command>sudo</command> to execute commands as
<literal>root</literal> and to configure the network, respectively. Also note
the SSH public key that allows remote logins with the corresponding private
key. Users created in this way do not have a password by default, so they
cannot log in via mechanisms that require a password. However, you can use
the <command>passwd</command> program to set a password, which is retained
across invocations of <command>nixos-rebuild</command>.
</para>
<para>
If you set <xref linkend="opt-users.mutableUsers"/> to false, then the
contents of <literal>/etc/passwd</literal> and <literal>/etc/group</literal>
will be congruent to your NixOS configuration. For instance, if you remove a
user from <xref linkend="opt-users.users"/> and run nixos-rebuild, the user
account will cease to exist. Also, imperative commands for managing users and
groups, such as useradd, are no longer available. Passwords may still be
assigned by setting the user's
<link linkend="opt-users.users._name__.hashedPassword">hashedPassword</link>
option. A hashed password can be generated using <command>mkpasswd -m
sha-512</command> after installing the <literal>mkpasswd</literal> package.
</para>
<para>
A user ID (uid) is assigned automatically. You can also specify a uid
manually by adding
<programlisting>
uid = 1000;
</programlisting>
to the user specification.</para>
<para>Groups can be specified similarly. The following states that a
group named <literal>students</literal> shall exist:
to the user specification.
</para>
<para>
Groups can be specified similarly. The following states that a group named
<literal>students</literal> shall exist:
<programlisting>
<xref linkend="opt-users.groups"/>.students.gid = 1000;
</programlisting>
As with users, the group ID (gid) is optional and will be assigned
automatically if it’s missing.</para>
<para>In the imperative style, users and groups are managed by
commands such as <command>useradd</command>,
<command>groupmod</command> and so on. For instance, to create a user
account named <literal>alice</literal>:
As with users, the group ID (gid) is optional and will be assigned
automatically if it’s missing.
</para>
<para>
In the imperative style, users and groups are managed by commands such as
<command>useradd</command>, <command>groupmod</command> and so on. For
instance, to create a user account named <literal>alice</literal>:
<screen>
# useradd -m alice</screen>
To make all nix tools available to this new user use `su - USER` which
opens a login shell (==shell that loads the profile) for given user.
This will create the ~/.nix-defexpr symlink. So run:
To make all nix tools available to this new user use `su - USER` which opens
a login shell (==shell that loads the profile) for given user. This will
create the ~/.nix-defexpr symlink. So run:
<screen>
# su - alice -c "true"</screen>
The flag <option>-m</option> causes the creation of a home directory
for the new user, which is generally what you want. The user does not
have an initial password and therefore cannot log in. A password can
be set using the <command>passwd</command> utility:
The flag <option>-m</option> causes the creation of a home directory for the
new user, which is generally what you want. The user does not have an initial
password and therefore cannot log in. A password can be set using the
<command>passwd</command> utility:
<screen>
# passwd alice
Enter new UNIX password: ***
Retype new UNIX password: ***
</screen>
A user can be deleted using <command>userdel</command>:
A user can be deleted using <command>userdel</command>:
<screen>
# userdel -r alice</screen>
The flag <option>-r</option> deletes the user’s home directory.
Accounts can be modified using <command>usermod</command>. Unix
groups can be managed using <command>groupadd</command>,
<command>groupmod</command> and <command>groupdel</command>.</para>
The flag <option>-r</option> deletes the user’s home directory. Accounts
can be modified using <command>usermod</command>. Unix groups can be managed
using <command>groupadd</command>, <command>groupmod</command> and
<command>groupdel</command>.
</para>
</chapter>

50
nixos/doc/manual/configuration/wireless.xml
View File

@ -3,22 +3,20 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-wireless">
<title>Wireless Networks</title>
<title>Wireless Networks</title>
<para>For a desktop installation using NetworkManager (e.g., GNOME),
you just have to make sure the user is in the
<code>networkmanager</code> group and you can skip the rest of this
section on wireless networks.</para>
<para>
NixOS will start wpa_supplicant for you if you enable this setting:
<para>
For a desktop installation using NetworkManager (e.g., GNOME), you just have
to make sure the user is in the <code>networkmanager</code> group and you can
skip the rest of this section on wireless networks.
</para>
<para>
NixOS will start wpa_supplicant for you if you enable this setting:
<programlisting>
<xref linkend="opt-networking.wireless.enable"/> = true;
</programlisting>
NixOS lets you specify networks for wpa_supplicant declaratively:
NixOS lets you specify networks for wpa_supplicant declaratively:
<programlisting>
<xref linkend="opt-networking.wireless.networks"/> = {
echelon = {
@ -27,27 +25,21 @@ NixOS lets you specify networks for wpa_supplicant declaratively:
"free.wifi" = {};
}
</programlisting>
Be aware that keys will be written to the nix store in plaintext! When no
networks are set, it will default to using a configuration file at
<literal>/etc/wpa_supplicant.conf</literal>. You should edit this file
yourself to define wireless networks, WPA keys and so on (see
wpa_supplicant.conf(5)).
</para>
Be aware that keys will be written to the nix store in plaintext!
When no networks are set, it will default to using a configuration file at
<literal>/etc/wpa_supplicant.conf</literal>. You should edit this file
yourself to define wireless networks, WPA keys and so on (see
wpa_supplicant.conf(5)).
</para>
<para>
If you are using WPA2 the <command>wpa_passphrase</command> tool might be useful
to generate the <literal>wpa_supplicant.conf</literal>.
<para>
If you are using WPA2 the <command>wpa_passphrase</command> tool might be
useful to generate the <literal>wpa_supplicant.conf</literal>.
<screen>
# wpa_passphrase ESSID PSK > /etc/wpa_supplicant.conf</screen>
After you have edited the <literal>wpa_supplicant.conf</literal>,
you need to restart the wpa_supplicant service.
After you have edited the <literal>wpa_supplicant.conf</literal>, you need to
restart the wpa_supplicant service.
<screen>
# systemctl restart wpa_supplicant.service</screen>
</para>
</para>
</section>

159
nixos/doc/manual/configuration/x-windows.xml
View File

@ -3,27 +3,25 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-x11">
<title>X Window System</title>
<para>The X Window System (X11) provides the basis of NixOS’ graphical
user interface. It can be enabled as follows:
<title>X Window System</title>
<para>
The X Window System (X11) provides the basis of NixOS’ graphical user
interface. It can be enabled as follows:
<programlisting>
<xref linkend="opt-services.xserver.enable"/> = true;
</programlisting>
The X server will automatically detect and use the appropriate video
driver from a set of X.org drivers (such as <literal>vesa</literal>
and <literal>intel</literal>). You can also specify a driver
manually, e.g.
The X server will automatically detect and use the appropriate video driver
from a set of X.org drivers (such as <literal>vesa</literal> and
<literal>intel</literal>). You can also specify a driver manually, e.g.
<programlisting>
<xref linkend="opt-services.xserver.videoDrivers"/> = [ "r128" ];
</programlisting>
to enable X.org’s <literal>xf86-video-r128</literal> driver.</para>
<para>You also need to enable at least one desktop or window manager.
Otherwise, you can only log into a plain undecorated
<command>xterm</command> window. Thus you should pick one or more of
the following lines:
to enable X.org’s <literal>xf86-video-r128</literal> driver.
</para>
<para>
You also need to enable at least one desktop or window manager. Otherwise,
you can only log into a plain undecorated <command>xterm</command> window.
Thus you should pick one or more of the following lines:
<programlisting>
<xref linkend="opt-services.xserver.desktopManager.plasma5.enable"/> = true;
<xref linkend="opt-services.xserver.desktopManager.xfce.enable"/> = true;
@ -33,108 +31,105 @@ the following lines:
<xref linkend="opt-services.xserver.windowManager.icewm.enable"/> = true;
<xref linkend="opt-services.xserver.windowManager.i3.enable"/> = true;
</programlisting>
</para>
<para>NixOS’s default <emphasis>display manager</emphasis> (the
program that provides a graphical login prompt and manages the X
server) is SLiM. You can select an alternative one by picking one
of the following lines:
</para>
<para>
NixOS’s default <emphasis>display manager</emphasis> (the program that
provides a graphical login prompt and manages the X server) is SLiM. You can
select an alternative one by picking one of the following lines:
<programlisting>
<xref linkend="opt-services.xserver.displayManager.sddm.enable"/> = true;
<xref linkend="opt-services.xserver.displayManager.lightdm.enable"/> = true;
</programlisting>
</para>
<para>You can set the keyboard layout (and optionally the layout variant):
</para>
<para>
You can set the keyboard layout (and optionally the layout variant):
<programlisting>
<xref linkend="opt-services.xserver.layout"/> = "de";
<xref linkend="opt-services.xserver.xkbVariant"/> = "neo";
</programlisting>
</para>
<para>The X server is started automatically at boot time. If you
don’t want this to happen, you can set:
</para>
<para>
The X server is started automatically at boot time. If you don’t want this
to happen, you can set:
<programlisting>
<xref linkend="opt-services.xserver.autorun"/> = false;
</programlisting>
The X server can then be started manually:
The X server can then be started manually:
<screen>
# systemctl start display-manager.service
</screen>
</para>
<simplesect><title>NVIDIA Graphics Cards</title>
<para>NVIDIA provides a proprietary driver for its graphics cards that
has better 3D performance than the X.org drivers. It is not enabled
by default because it’s not free software. You can enable it as follows:
</para>
<simplesect>
<title>NVIDIA Graphics Cards</title>
<para>
NVIDIA provides a proprietary driver for its graphics cards that has better
3D performance than the X.org drivers. It is not enabled by default because
it’s not free software. You can enable it as follows:
<programlisting>
<xref linkend="opt-services.xserver.videoDrivers"/> = [ "nvidia" ];
</programlisting>
Or if you have an older card, you may have to use one of the legacy drivers:
Or if you have an older card, you may have to use one of the legacy drivers:
<programlisting>
<xref linkend="opt-services.xserver.videoDrivers"/> = [ "nvidiaLegacy340" ];
<xref linkend="opt-services.xserver.videoDrivers"/> = [ "nvidiaLegacy304" ];
<xref linkend="opt-services.xserver.videoDrivers"/> = [ "nvidiaLegacy173" ];
</programlisting>
You may need to reboot after enabling this driver to prevent a clash
with other kernel modules.</para>
<para>On 64-bit systems, if you want full acceleration for 32-bit
programs such as Wine, you should also set the following:
You may need to reboot after enabling this driver to prevent a clash with
other kernel modules.
</para>
<para>
On 64-bit systems, if you want full acceleration for 32-bit programs such as
Wine, you should also set the following:
<programlisting>
<xref linkend="opt-hardware.opengl.driSupport32Bit"/> = true;
</programlisting>
</para>
</simplesect>
<simplesect><title>AMD Graphics Cards</title>
<para>AMD provides a proprietary driver for its graphics cards that
has better 3D performance than the X.org drivers. It is not enabled
by default because it’s not free software. You can enable it as follows:
</para>
</simplesect>
<simplesect>
<title>AMD Graphics Cards</title>
<para>
AMD provides a proprietary driver for its graphics cards that has better 3D
performance than the X.org drivers. It is not enabled by default because
it’s not free software. You can enable it as follows:
<programlisting>
<xref linkend="opt-services.xserver.videoDrivers"/> = [ "ati_unfree" ];
</programlisting>
You will need to reboot after enabling this driver to prevent a clash
with other kernel modules.</para>
<para>On 64-bit systems, if you want full acceleration for 32-bit
programs such as Wine, you should also set the following:
You will need to reboot after enabling this driver to prevent a clash with
other kernel modules.
</para>
<para>
On 64-bit systems, if you want full acceleration for 32-bit programs such as
Wine, you should also set the following:
<programlisting>
<xref linkend="opt-hardware.opengl.driSupport32Bit"/> = true;
</programlisting>
</para>
</simplesect>
<simplesect><title>Touchpads</title>
<para>Support for Synaptics touchpads (found in many laptops such as
the Dell Latitude series) can be enabled as follows:
</para>
</simplesect>
<simplesect>
<title>Touchpads</title>
<para>
Support for Synaptics touchpads (found in many laptops such as the Dell
Latitude series) can be enabled as follows:
<programlisting>
<xref linkend="opt-services.xserver.libinput.enable"/> = true;
</programlisting>
The driver has many options (see <xref linkend="ch-options"/>). For
instance, the following disables tap-to-click behavior:
The driver has many options (see <xref linkend="ch-options"/>). For
instance, the following disables tap-to-click behavior:
<programlisting>
<xref linkend="opt-services.xserver.libinput.tapping"/> = false;
</programlisting>
Note: the use of <literal>services.xserver.synaptics</literal> is deprecated since NixOS 17.09.
</para>
</simplesect>
<simplesect><title>GTK/Qt themes</title>
<para>GTK themes can be installed either to user profile or system-wide (via
<literal>environment.systemPackages</literal>). To make Qt 5 applications look similar
to GTK2 ones, you can install <literal>qt5.qtbase.gtk</literal> package into your
system environment. It should work for all Qt 5 library versions.
</para>
</simplesect>
Note: the use of <literal>services.xserver.synaptics</literal> is deprecated
since NixOS 17.09.
</para>
</simplesect>
<simplesect>
<title>GTK/Qt themes</title>
<para>
GTK themes can be installed either to user profile or system-wide (via
<literal>environment.systemPackages</literal>). To make Qt 5 applications
look similar to GTK2 ones, you can install <literal>qt5.qtbase.gtk</literal>
package into your system environment. It should work for all Qt 5 library
versions.
</para>
</simplesect>
</chapter>

116
nixos/doc/manual/configuration/xfce.xml
View File

@ -3,23 +3,20 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-xfce">
<title>Xfce Desktop Environment</title>
<para>
To enable the Xfce Desktop Environment, set
<programlisting>
<title>Xfce Desktop Environment</title>
<para>
To enable the Xfce Desktop Environment, set
<programlisting>
<link linkend="opt-services.xserver.desktopManager.default">services.xserver.desktopManager</link> = {
<link linkend="opt-services.xserver.desktopManager.xfce.enable">xfce.enable</link> = true;
<link linkend="opt-services.xserver.desktopManager.default">default</link> = "xfce";
};
</programlisting>
</para>
<para>
Optionally, <emphasis>compton</emphasis>
can be enabled for nice graphical effects, some example settings:
<programlisting>
</para>
<para>
Optionally, <emphasis>compton</emphasis> can be enabled for nice graphical
effects, some example settings:
<programlisting>
<link linkend="opt-services.compton.enable">services.compton</link> = {
<link linkend="opt-services.compton.enable">enable</link> = true;
<link linkend="opt-services.compton.fade">fade</link> = true;
@ -28,67 +25,48 @@
<link linkend="opt-services.compton.fadeDelta">fadeDelta</link> = 4;
};
</programlisting>
</para>
<para>
Some Xfce programs are not installed automatically.
To install them manually (system wide), put them into your
<xref linkend="opt-environment.systemPackages"/>.
</para>
<simplesect>
<title>Thunar Volume Support</title>
<para>
To enable
<emphasis>Thunar</emphasis>
volume support, put
<programlisting>
</para>
<para>
Some Xfce programs are not installed automatically. To install them manually
(system wide), put them into your
<xref linkend="opt-environment.systemPackages"/>.
</para>
<simplesect>
<title>Thunar Volume Support</title>
<para>
To enable <emphasis>Thunar</emphasis> volume support, put
<programlisting>
<xref linkend="opt-services.xserver.desktopManager.xfce.enable"/> = true;
</programlisting>
into your <emphasis>configuration.nix</emphasis>.
</para>
</simplesect>
<simplesect>
<title>Polkit Authentication Agent</title>
<para>
There is no authentication agent automatically installed alongside
Xfce. To allow mounting of local (non-removable) filesystems, you
will need to install one.
Installing <emphasis>polkit_gnome</emphasis>, a rebuild, logout and
login did the trick.
</para>
</simplesect>
<simplesect>
<title>Troubleshooting</title>
<para>
Even after enabling udisks2, volume management might not work.
Thunar and/or the desktop takes time to show up.
Thunar will spit out this kind of message on start
(look at <command>journalctl --user -b</command>).
<programlisting>
into your <emphasis>configuration.nix</emphasis>.
</para>
</simplesect>
<simplesect>
<title>Polkit Authentication Agent</title>
<para>
There is no authentication agent automatically installed alongside Xfce. To
allow mounting of local (non-removable) filesystems, you will need to
install one. Installing <emphasis>polkit_gnome</emphasis>, a rebuild, logout
and login did the trick.
</para>
</simplesect>
<simplesect>
<title>Troubleshooting</title>
<para>
Even after enabling udisks2, volume management might not work. Thunar and/or
the desktop takes time to show up. Thunar will spit out this kind of message
on start (look at <command>journalctl --user -b</command>).
<programlisting>
Thunar:2410): GVFS-RemoteVolumeMonitor-WARNING **: remote volume monitor with dbus name org.gtk.Private.UDisks2VolumeMonitor is not supported
</programlisting>
This is caused by some needed GNOME services not running.
This is all fixed by enabling "Launch GNOME services on startup" in
the Advanced tab of the Session and Startup settings panel.
Alternatively, you can run this command to do the same thing.
<programlisting>
This is caused by some needed GNOME services not running. This is all fixed
by enabling "Launch GNOME services on startup" in the Advanced tab of the
Session and Startup settings panel. Alternatively, you can run this command
to do the same thing.
<programlisting>
$ xfconf-query -c xfce4-session -p /compat/LaunchGNOME -s true
</programlisting>
A log-out and re-log will be needed for this to take effect.
</para>
</simplesect>
A log-out and re-log will be needed for this to take effect.
</para>
</simplesect>
</chapter>

64
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@ -3,30 +3,29 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-assertions">
<title>Warnings and Assertions</title>
<title>Warnings and Assertions</title>
<para>
When configuration problems are detectable in a module, it is a good idea to
write an assertion or warning. Doing so provides clear feedback to the user
and prevents errors after the build.
</para>
<para>
When configuration problems are detectable in a module, it is a good
idea to write an assertion or warning. Doing so provides clear
feedback to the user and prevents errors after the build.
</para>
<para>
<para>
Although Nix has the <literal>abort</literal> and
<literal>builtins.trace</literal> <link xlink:href="https://nixos.org/nix/manual/#ssec-builtins">functions</link> to perform such tasks,
they are not ideally suited for NixOS modules. Instead of these
functions, you can declare your warnings and assertions using the
<literal>builtins.trace</literal>
<link xlink:href="https://nixos.org/nix/manual/#ssec-builtins">functions</link>
to perform such tasks, they are not ideally suited for NixOS modules. Instead
of these functions, you can declare your warnings and assertions using the
NixOS module system.
</para>
</para>
<section>
<section>
<title>Warnings</title>
<title>Warnings</title>
<para>
This is an example of using <literal>warnings</literal>.
</para>
<para>
This is an example of using <literal>warnings</literal>.
</para>
<programlisting>
<![CDATA[
@ -43,22 +42,19 @@
}
]]>
</programlisting>
</section>
</section>
<section>
<title>Assertions</title>
<section>
<title>Assertions</title>
<para>
This example, extracted from the
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/release-17.09/nixos/modules/services/logging/syslogd.nix">
<literal>syslogd</literal> module
</link> shows how to use <literal>assertions</literal>. Since there
can only be one active syslog daemon at a time, an assertion is useful to
prevent such a broken system from being built.
</para>
<para>
This example, extracted from the
<link xlink:href="https://github.com/NixOS/nixpkgs/blob/release-17.09/nixos/modules/services/logging/syslogd.nix">
<literal>syslogd</literal> module </link> shows how to use
<literal>assertions</literal>. Since there can only be one active syslog
daemon at a time, an assertion is useful to prevent such a broken system
from being built.
</para>
<programlisting>
<![CDATA[
@ -74,7 +70,5 @@
}
]]>
</programlisting>
</section>
</section>
</section>

35
nixos/doc/manual/development/building-nixos.xml
View File

@ -3,30 +3,25 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-building-cd">
<title>Building Your Own NixOS CD</title>
<para>Building a NixOS CD is as easy as configuring your own computer. The
idea is to use another module which will replace
your <filename>configuration.nix</filename> to configure the system that
would be installed on the CD.</para>
<para>Default CD/DVD configurations are available
inside <filename>nixos/modules/installer/cd-dvd</filename>.
<title>Building Your Own NixOS CD</title>
<para>
Building a NixOS CD is as easy as configuring your own computer. The idea is
to use another module which will replace your
<filename>configuration.nix</filename> to configure the system that would be
installed on the CD.
</para>
<para>
Default CD/DVD configurations are available inside
<filename>nixos/modules/installer/cd-dvd</filename>.
<screen>
$ git clone https://github.com/NixOS/nixpkgs.git
$ cd nixpkgs/nixos
$ nix-build -A config.system.build.isoImage -I nixos-config=modules/installer/cd-dvd/installation-cd-minimal.nix default.nix</screen>
</para>
<para>Before burning your CD/DVD, you can check the content of the image by mounting anywhere like
suggested by the following command:
</para>
<para>
Before burning your CD/DVD, you can check the content of the image by
mounting anywhere like suggested by the following command:
<screen>
# mount -o loop -t iso9660 ./result/iso/cd.iso /mnt/iso</screen>
</para>
</para>
</chapter>

157
nixos/doc/manual/development/building-parts.xml
View File

@ -3,111 +3,110 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-building-parts">
<title>Building Specific Parts of NixOS</title>
<para>With the command <command>nix-build</command>, you can build
specific parts of your NixOS configuration. This is done as follows:
<title>Building Specific Parts of NixOS</title>
<para>
With the command <command>nix-build</command>, you can build specific parts
of your NixOS configuration. This is done as follows:
<screen>
$ cd <replaceable>/path/to/nixpkgs/nixos</replaceable>
$ nix-build -A config.<replaceable>option</replaceable></screen>
where <replaceable>option</replaceable> is a NixOS option with type
“derivation” (i.e. something that can be built). Attributes of
interest include:
<variablelist>
<varlistentry>
<term><varname>system.build.toplevel</varname></term>
where <replaceable>option</replaceable> is a NixOS option with type
“derivation” (i.e. something that can be built). Attributes of interest
include:
<variablelist>
<varlistentry>
<term><varname>system.build.toplevel</varname>
</term>
<listitem>
<para>The top-level option that builds the entire NixOS system.
Everything else in your configuration is indirectly pulled in by
this option. This is what <command>nixos-rebuild</command>
builds and what <filename>/run/current-system</filename> points
to afterwards.</para>
<para>A shortcut to build this is:
<para>
The top-level option that builds the entire NixOS system. Everything else
in your configuration is indirectly pulled in by this option. This is
what <command>nixos-rebuild</command> builds and what
<filename>/run/current-system</filename> points to afterwards.
</para>
<para>
A shortcut to build this is:
<screen>
$ nix-build -A system</screen>
</para>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>system.build.manual.manual</varname></term>
<listitem><para>The NixOS manual.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>system.build.etc</varname></term>
<listitem><para>A tree of symlinks that form the static parts of
<filename>/etc</filename>.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>system.build.initialRamdisk</varname></term>
<term><varname>system.build.kernel</varname></term>
</varlistentry>
<varlistentry>
<term><varname>system.build.manual.manual</varname>
</term>
<listitem>
<para>The initial ramdisk and kernel of the system. This allows
a quick way to test whether the kernel and the initial ramdisk
boot correctly, by using QEMU’s <option>-kernel</option> and
<option>-initrd</option> options:
<para>
The NixOS manual.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>system.build.etc</varname>
</term>
<listitem>
<para>
A tree of symlinks that form the static parts of
<filename>/etc</filename>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>system.build.initialRamdisk</varname>
</term>
<term><varname>system.build.kernel</varname>
</term>
<listitem>
<para>
The initial ramdisk and kernel of the system. This allows a quick way to
test whether the kernel and the initial ramdisk boot correctly, by using
QEMU’s <option>-kernel</option> and <option>-initrd</option> options:
<screen>
$ nix-build -A config.system.build.initialRamdisk -o initrd
$ nix-build -A config.system.build.kernel -o kernel
$ qemu-system-x86_64 -kernel ./kernel/bzImage -initrd ./initrd/initrd -hda /dev/null
</screen>
</para>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>system.build.nixos-rebuild</varname></term>
<term><varname>system.build.nixos-install</varname></term>
<term><varname>system.build.nixos-generate-config</varname></term>
</varlistentry>
<varlistentry>
<term><varname>system.build.nixos-rebuild</varname>
</term>
<term><varname>system.build.nixos-install</varname>
</term>
<term><varname>system.build.nixos-generate-config</varname>
</term>
<listitem>
<para>These build the corresponding NixOS commands.</para>
<para>
These build the corresponding NixOS commands.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>systemd.units.<replaceable>unit-name</replaceable>.unit</varname></term>
</varlistentry>
<varlistentry>
<term><varname>systemd.units.<replaceable>unit-name</replaceable>.unit</varname>
</term>
<listitem>
<para>This builds the unit with the specified name. Note that
since unit names contain dots
(e.g. <literal>httpd.service</literal>), you need to put them
between quotes, like this:
<para>
This builds the unit with the specified name. Note that since unit names
contain dots (e.g. <literal>httpd.service</literal>), you need to put
them between quotes, like this:
<screen>
$ nix-build -A 'config.systemd.units."httpd.service".unit'
</screen>
You can also test individual units, without rebuilding the whole
system, by putting them in
<filename>/run/systemd/system</filename>:
You can also test individual units, without rebuilding the whole system,
by putting them in <filename>/run/systemd/system</filename>:
<screen>
$ cp $(nix-build -A 'config.systemd.units."httpd.service".unit')/httpd.service \
/run/systemd/system/tmp-httpd.service
# systemctl daemon-reload
# systemctl start tmp-httpd.service
</screen>
Note that the unit must not have the same name as any unit in
<filename>/etc/systemd/system</filename> since those take
precedence over <filename>/run/systemd/system</filename>.
That’s why the unit is installed as
<filename>tmp-httpd.service</filename> here.</para>
<filename>/etc/systemd/system</filename> since those take precedence over
<filename>/run/systemd/system</filename>. That’s why the unit is
installed as <filename>tmp-httpd.service</filename> here.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</varlistentry>
</variablelist>
</para>
</chapter>

31
nixos/doc/manual/development/development.xml
View File

@ -3,21 +3,18 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="ch-development">
<title>Development</title>
<partintro>
<para>This chapter describes how you can modify and extend
NixOS.</para>
</partintro>
<xi:include href="sources.xml" />
<xi:include href="writing-modules.xml" />
<xi:include href="building-parts.xml" />
<xi:include href="writing-documentation.xml" />
<xi:include href="building-nixos.xml" />
<xi:include href="nixos-tests.xml" />
<xi:include href="testing-installer.xml" />
<xi:include href="releases.xml" />
<title>Development</title>
<partintro>
<para>
This chapter describes how you can modify and extend NixOS.
</para>
</partintro>
<xi:include href="sources.xml" />
<xi:include href="writing-modules.xml" />
<xi:include href="building-parts.xml" />
<xi:include href="writing-documentation.xml" />
<xi:include href="building-nixos.xml" />
<xi:include href="nixos-tests.xml" />
<xi:include href="testing-installer.xml" />
<xi:include href="releases.xml" />
</part>

23
nixos/doc/manual/development/importing-modules.xml
View File

@ -3,13 +3,12 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-importing-modules">
<title>Importing Modules</title>
<title>Importing Modules</title>
<para>
Sometimes NixOS modules need to be used in configuration but exist
outside of Nixpkgs. These modules can be imported:
</para>
<para>
Sometimes NixOS modules need to be used in configuration but exist outside of
Nixpkgs. These modules can be imported:
</para>
<programlisting>
{ config, lib, pkgs, ... }:
@ -25,12 +24,11 @@
}
</programlisting>
<para>
The environment variable <literal>NIXOS_EXTRA_MODULE_PATH</literal> is
an absolute path to a NixOS module that is included alongside the
Nixpkgs NixOS modules. Like any NixOS module, this module can import
additional modules:
</para>
<para>
The environment variable <literal>NIXOS_EXTRA_MODULE_PATH</literal> is an
absolute path to a NixOS module that is included alongside the Nixpkgs NixOS
modules. Like any NixOS module, this module can import additional modules:
</para>
<programlisting>
# ./module-list/default.nix
@ -55,5 +53,4 @@
services.exampleModule1.enable = true;
}
</programlisting>
</section>

55
nixos/doc/manual/development/meta-attributes.xml
View File

@ -3,22 +3,26 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-meta-attributes">
<title>Meta Attributes</title>
<title>Meta Attributes</title>
<para>Like Nix packages, NixOS modules can declare meta-attributes to provide
extra information. Module meta attributes are defined in the
<para>
Like Nix packages, NixOS modules can declare meta-attributes to provide extra
information. Module meta attributes are defined in the
<filename
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/misc/meta.nix">meta.nix</filename>
special module.</para>
special module.
</para>
<para><literal>meta</literal> is a top level attribute like
<para>
<literal>meta</literal> is a top level attribute like
<literal>options</literal> and <literal>config</literal>. Available
meta-attributes are <literal>maintainers</literal> and
<literal>doc</literal>.</para>
<literal>doc</literal>.
</para>
<para>Each of the meta-attributes must be defined at most once per module
file.</para>
<para>
Each of the meta-attributes must be defined at most once per module file.
</para>
<programlisting>
{ config, lib, pkgs, ... }:
@ -39,24 +43,21 @@
}
</programlisting>
<calloutlist>
<callout arearefs='modules-meta-1'>
<para>
<calloutlist>
<callout arearefs='modules-meta-1'>
<para>
<varname>maintainers</varname> contains a list of the module maintainers.
</para>
</callout>
<callout arearefs='modules-meta-2'>
<para>
</para>
</callout>
<callout arearefs='modules-meta-2'>
<para>
<varname>doc</varname> points to a valid DocBook file containing the module
documentation. Its contents is automatically added to <xref
linkend="ch-configuration"/>.
Changes to a module documentation have to be checked to not break
building the NixOS manual:
</para>
<programlisting>$ nix-build nixos/release.nix -A manual</programlisting>
</callout>
</calloutlist>
documentation. Its contents is automatically added to
<xref
linkend="ch-configuration"/>. Changes to a module documentation
have to be checked to not break building the NixOS manual:
</para>
<programlisting>$ nix-build nixos/release.nix -A manual</programlisting>
</callout>
</calloutlist>
</section>

25
nixos/doc/manual/development/nixos-tests.xml
View File

@ -3,18 +3,17 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-nixos-tests">
<title>NixOS Tests</title>
<para>When you add some feature to NixOS, you should write a test for
it. NixOS tests are kept in the directory <filename
<title>NixOS Tests</title>
<para>
When you add some feature to NixOS, you should write a test for it. NixOS
tests are kept in the directory
<filename
xlink:href="https://github.com/NixOS/nixpkgs/tree/master/nixos/tests">nixos/tests</filename>,
and are executed (using Nix) by a testing framework that automatically
starts one or more virtual machines containing the NixOS system(s)
required for the test.</para>
<xi:include href="writing-nixos-tests.xml" />
<xi:include href="running-nixos-tests.xml" />
<xi:include href="running-nixos-tests-interactively.xml" />
and are executed (using Nix) by a testing framework that automatically starts
one or more virtual machines containing the NixOS system(s) required for the
test.
</para>
<xi:include href="writing-nixos-tests.xml" />
<xi:include href="running-nixos-tests.xml" />
<xi:include href="running-nixos-tests-interactively.xml" />
</chapter>

257
nixos/doc/manual/development/option-declarations.xml
View File

@ -3,14 +3,12 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-option-declarations">
<title>Option Declarations</title>
<title>Option Declarations</title>
<para>An option declaration specifies the name, type and description
of a NixOS configuration option. It is invalid to define an option
that hasn’t been declared in any module. An option declaration
generally looks like this:
<para>
An option declaration specifies the name, type and description of a NixOS
configuration option. It is invalid to define an option that hasn’t been
declared in any module. An option declaration generally looks like this:
<programlisting>
options = {
<replaceable>name</replaceable> = mkOption {
@ -21,146 +19,177 @@ options = {
};
};
</programlisting>
The attribute names within the <replaceable>name</replaceable>
attribute path must be camel cased in general but should, as an
exception, match the
<link
The attribute names within the <replaceable>name</replaceable> attribute path
must be camel cased in general but should, as an exception, match the
<link
xlink:href="https://nixos.org/nixpkgs/manual/#sec-package-naming">
package attribute name</link> when referencing a Nixpkgs package. For
example, the option <varname>services.nix-serve.bindAddress</varname>
references the <varname>nix-serve</varname> Nixpkgs package.
package attribute name</link> when referencing a Nixpkgs package. For
example, the option <varname>services.nix-serve.bindAddress</varname>
references the <varname>nix-serve</varname> Nixpkgs package.
</para>
</para>
<para>The function <varname>mkOption</varname> accepts the following arguments.
<variablelist>
<varlistentry>
<term><varname>type</varname></term>
<para>
The function <varname>mkOption</varname> accepts the following arguments.
<variablelist>
<varlistentry>
<term><varname>type</varname>
</term>
<listitem>
<para>The type of the option (see <xref linkend='sec-option-types' />).
It may be omitted, but that’s not advisable since it may lead to errors
that are hard to diagnose.</para>
<para>
The type of the option (see <xref linkend='sec-option-types' />). It may
be omitted, but that’s not advisable since it may lead to errors that
are hard to diagnose.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>default</varname></term>
</varlistentry>
<varlistentry>
<term><varname>default</varname>
</term>
<listitem>
<para>The default value used if no value is defined by any
module. A default is not required; but if a default is not given,
then users of the module will have to define the value of the
option, otherwise an error will be thrown.</para>
<para>
The default value used if no value is defined by any module. A default is
not required; but if a default is not given, then users of the module
will have to define the value of the option, otherwise an error will be
thrown.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>example</varname></term>
</varlistentry>
<varlistentry>
<term><varname>example</varname>
</term>
<listitem>
<para>An example value that will be shown in the NixOS manual.</para>
<para>
An example value that will be shown in the NixOS manual.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>description</varname></term>
</varlistentry>
<varlistentry>
<term><varname>description</varname>
</term>
<listitem>
<para>A textual description of the option, in DocBook format,
that will be included in the NixOS manual.</para>
<para>
A textual description of the option, in DocBook format, that will be
included in the NixOS manual.
</para>
</listitem>
</varlistentry>
</varlistentry>
</variablelist>
</para>
</variablelist>
<section xml:id="sec-option-declarations-eot">
<title>Extensible Option Types</title>
</para>
<section xml:id="sec-option-declarations-eot"><title>Extensible Option
Types</title>
<para>Extensible option types is a feature that allow to extend certain types
declaration through multiple module files.
This feature only work with a restricted set of types, namely
<literal>enum</literal> and <literal>submodules</literal> and any composed
forms of them.</para>
<para>Extensible option types can be used for <literal>enum</literal> options
that affects multiple modules, or as an alternative to related
<literal>enable</literal> options.</para>
<para>As an example, we will take the case of display managers. There is a
central display manager module for generic display manager options and a
module file per display manager backend (slim, sddm, gdm ...).
<para>
Extensible option types is a feature that allow to extend certain types
declaration through multiple module files. This feature only work with a
restricted set of types, namely <literal>enum</literal> and
<literal>submodules</literal> and any composed forms of them.
</para>
<para>There are two approach to this module structure:
<itemizedlist>
<listitem><para>Managing the display managers independently by adding an
enable option to every display manager module backend. (NixOS)</para>
</listitem>
<listitem><para>Managing the display managers in the central module by
adding an option to select which display manager backend to use.</para>
</listitem>
</itemizedlist>
<para>
Extensible option types can be used for <literal>enum</literal> options that
affects multiple modules, or as an alternative to related
<literal>enable</literal> options.
</para>
<para>Both approaches have problems.</para>
<para>
As an example, we will take the case of display managers. There is a central
display manager module for generic display manager options and a module file
per display manager backend (slim, sddm, gdm ...).
</para>
<para>Making backends independent can quickly become hard to manage. For
display managers, there can be only one enabled at a time, but the type
system can not enforce this restriction as there is no relation between
each backend <literal>enable</literal> option. As a result, this restriction
has to be done explicitely by adding assertions in each display manager
backend module.</para>
<para>
There are two approach to this module structure:
<itemizedlist>
<listitem>
<para>
Managing the display managers independently by adding an enable option to
every display manager module backend. (NixOS)
</para>
</listitem>
<listitem>
<para>
Managing the display managers in the central module by adding an option
to select which display manager backend to use.
</para>
</listitem>
</itemizedlist>
</para>
<para>On the other hand, managing the display managers backends in the
central module will require to change the central module option every time
a new backend is added or removed.</para>
<para>
Both approaches have problems.
</para>
<para>By using extensible option types, it is possible to create a placeholder
option in the central module (<xref linkend='ex-option-declaration-eot-service'
/>), and to extend it in each backend module (<xref
linkend='ex-option-declaration-eot-backend-slim' />, <xref
linkend='ex-option-declaration-eot-backend-sddm' />).</para>
<para>
Making backends independent can quickly become hard to manage. For display
managers, there can be only one enabled at a time, but the type system can
not enforce this restriction as there is no relation between each backend
<literal>enable</literal> option. As a result, this restriction has to be
done explicitely by adding assertions in each display manager backend
module.
</para>
<para>As a result, <literal>displayManager.enable</literal> option values can
be added without changing the main service module file and the type system
automatically enforce that there can only be a single display manager
enabled.</para>
<para>
On the other hand, managing the display managers backends in the central
module will require to change the central module option every time a new
backend is added or removed.
</para>
<example xml:id='ex-option-declaration-eot-service'><title>Extensible type
placeholder in the service module</title>
<para>
By using extensible option types, it is possible to create a placeholder
option in the central module
(<xref linkend='ex-option-declaration-eot-service'
/>), and to extend
it in each backend module
(<xref
linkend='ex-option-declaration-eot-backend-slim' />,
<xref
linkend='ex-option-declaration-eot-backend-sddm' />).
</para>
<para>
As a result, <literal>displayManager.enable</literal> option values can be
added without changing the main service module file and the type system
automatically enforce that there can only be a single display manager
enabled.
</para>
<example xml:id='ex-option-declaration-eot-service'>
<title>Extensible type placeholder in the service module</title>
<screen>
services.xserver.displayManager.enable = mkOption {
description = "Display manager to use";
type = with types; nullOr (enum [ ]);
};</screen></example>
};</screen>
</example>
<example xml:id='ex-option-declaration-eot-backend-slim'><title>Extending
<literal>services.xserver.displayManager.enable</literal> in the
<literal>slim</literal> module</title>
<example xml:id='ex-option-declaration-eot-backend-slim'>
<title>Extending <literal>services.xserver.displayManager.enable</literal> in the <literal>slim</literal> module</title>
<screen>
services.xserver.displayManager.enable = mkOption {
type = with types; nullOr (enum [ "slim" ]);
};</screen></example>
};</screen>
</example>
<example xml:id='ex-option-declaration-eot-backend-sddm'><title>Extending
<literal>services.xserver.displayManager.enable</literal> in the
<literal>sddm</literal> module</title>
<example xml:id='ex-option-declaration-eot-backend-sddm'>
<title>Extending <literal>services.xserver.displayManager.enable</literal> in the <literal>sddm</literal> module</title>
<screen>
services.xserver.displayManager.enable = mkOption {
type = with types; nullOr (enum [ "sddm" ]);
};</screen></example>
};</screen>
</example>
<para>The placeholder declaration is a standard <literal>mkOption</literal>
declaration, but it is important that extensible option declarations only use
the <literal>type</literal> argument.</para>
<para>Extensible option types work with any of the composed variants of
<literal>enum</literal> such as
<literal>with types; nullOr (enum [ "foo" "bar" ])</literal>
or <literal>with types; listOf (enum [ "foo" "bar" ])</literal>.</para>
<para>
The placeholder declaration is a standard <literal>mkOption</literal>
declaration, but it is important that extensible option declarations only
use the <literal>type</literal> argument.
</para>
</section>
<para>
Extensible option types work with any of the composed variants of
<literal>enum</literal> such as <literal>with types; nullOr (enum [ "foo"
"bar" ])</literal> or <literal>with types; listOf (enum [ "foo" "bar"
])</literal>.
</para>
</section>
</section>

103
nixos/doc/manual/development/option-def.xml
View File

@ -3,39 +3,36 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-option-definitions">
<title>Option Definitions</title>
<title>Option Definitions</title>
<para>Option definitions are generally straight-forward bindings of values to option names, like
<para>
Option definitions are generally straight-forward bindings of values to
option names, like
<programlisting>
config = {
services.httpd.enable = true;
};
</programlisting>
However, sometimes you need to wrap an option definition or set of option
definitions in a <emphasis>property</emphasis> to achieve certain effects:
</para>
However, sometimes you need to wrap an option definition or set of
option definitions in a <emphasis>property</emphasis> to achieve
certain effects:</para>
<simplesect><title>Delaying Conditionals</title>
<para>If a set of option definitions is conditional on the value of
another option, you may need to use <varname>mkIf</varname>.
Consider, for instance:
<simplesect>
<title>Delaying Conditionals</title>
<para>
If a set of option definitions is conditional on the value of another
option, you may need to use <varname>mkIf</varname>. Consider, for instance:
<programlisting>
config = if config.services.httpd.enable then {
environment.systemPackages = [ <replaceable>...</replaceable> ];
<replaceable>...</replaceable>
} else {};
</programlisting>
This definition will cause Nix to fail with an “infinite recursion”
error. Why? Because the value of
<option>config.services.httpd.enable</option> depends on the value
being constructed here. After all, you could also write the clearly
circular and contradictory:
This definition will cause Nix to fail with an “infinite recursion”
error. Why? Because the value of
<option>config.services.httpd.enable</option> depends on the value being
constructed here. After all, you could also write the clearly circular and
contradictory:
<programlisting>
config = if config.services.httpd.enable then {
services.httpd.enable = false;
@ -43,56 +40,49 @@ config = if config.services.httpd.enable then {
services.httpd.enable = true;
};
</programlisting>
The solution is to write:
The solution is to write:
<programlisting>
config = mkIf config.services.httpd.enable {
environment.systemPackages = [ <replaceable>...</replaceable> ];
<replaceable>...</replaceable>
};
</programlisting>
The special function <varname>mkIf</varname> causes the evaluation of
the conditional to be “pushed down” into the individual definitions,
as if you had written:
The special function <varname>mkIf</varname> causes the evaluation of the
conditional to be “pushed down” into the individual definitions, as if
you had written:
<programlisting>
config = {
environment.systemPackages = if config.services.httpd.enable then [ <replaceable>...</replaceable> ] else [];
<replaceable>...</replaceable>
};
</programlisting>
</para>
</simplesect>
</para>
</simplesect>
<simplesect><title>Setting Priorities</title>
<para>A module can override the definitions of an option in other
modules by setting a <emphasis>priority</emphasis>. All option
definitions that do not have the lowest priority value are discarded.
By default, option definitions have priority 1000. You can specify an
explicit priority by using <varname>mkOverride</varname>, e.g.
<simplesect>
<title>Setting Priorities</title>
<para>
A module can override the definitions of an option in other modules by
setting a <emphasis>priority</emphasis>. All option definitions that do not
have the lowest priority value are discarded. By default, option definitions
have priority 1000. You can specify an explicit priority by using
<varname>mkOverride</varname>, e.g.
<programlisting>
services.openssh.enable = mkOverride 10 false;
</programlisting>
This definition causes all other definitions with priorities above 10 to be
discarded. The function <varname>mkForce</varname> is equal to
<varname>mkOverride 50</varname>.
</para>
</simplesect>
This definition causes all other definitions with priorities above 10
to be discarded. The function <varname>mkForce</varname> is
equal to <varname>mkOverride 50</varname>.</para>
</simplesect>
<simplesect><title>Merging Configurations</title>
<para>In conjunction with <literal>mkIf</literal>, it is sometimes
useful for a module to return multiple sets of option definitions, to
be merged together as if they were declared in separate modules. This
can be done using <varname>mkMerge</varname>:
<simplesect>
<title>Merging Configurations</title>
<para>
In conjunction with <literal>mkIf</literal>, it is sometimes useful for a
module to return multiple sets of option definitions, to be merged together
as if they were declared in separate modules. This can be done using
<varname>mkMerge</varname>:
<programlisting>
config = mkMerge
[ # Unconditional stuff.
@ -104,9 +94,6 @@ config = mkMerge
})
];
</programlisting>
</para>
</simplesect>
</para>
</simplesect>
</section>

993
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448
nixos/doc/manual/development/releases.xml
View File

@ -3,252 +3,258 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="ch-releases">
<title>Releases</title>
<section xml:id="release-process">
<title>Releases</title>
<section xml:id="release-process">
<title>Release process</title>
<para>
Going through an example of releasing NixOS 17.09:
Going through an example of releasing NixOS 17.09:
</para>
<section xml:id="one-month-before-the-beta">
<title>One month before the beta</title>
<itemizedlist spacing="compact">
<listitem>
<para>
Send an email to the nix-devel mailinglist as a warning about upcoming beta "feature freeze" in a month.
</para>
</listitem>
<listitem>
<para>
Discuss with Eelco Dolstra and the community (via IRC, ML) about what will reach the deadline.
Any issue or Pull Request targeting the release should be included in the release milestone.
</para>
</listitem>
</itemizedlist>
</section>
<section xml:id="at-beta-release-time">
<title>At beta release time</title>
<itemizedlist spacing="compact">
<listitem>
<para>
<link xlink:href="https://github.com/NixOS/nixpkgs/issues/13559">Create
an issue for tracking Zero Hydra Failures progress. ZHF is an effort
to get build failures down to zero.</link>
</para>
</listitem>
<listitem>
<para>
<literal>git tag -a -s -m &quot;Release 17.09-beta&quot; 17.09-beta &amp;&amp; git push --tags</literal>
</para>
</listitem>
<listitem>
<para>
From the master branch run <literal>git checkout -B release-17.09</literal>.
</para>
</listitem>
<listitem>
<para>
<link xlink:href="https://github.com/NixOS/nixos-org-configurations/pull/18">
Make sure a channel is created at http://nixos.org/channels/.
</link>
</para>
</listitem>
<listitem>
<para>
<link xlink:href="https://github.com/NixOS/nixpkgs/settings/branches">
Let a GitHub nixpkgs admin lock the branch on github for you.
(so developers can’t force push)
</link>
</para>
</listitem>
<listitem>
<para>
<link xlink:href="https://github.com/NixOS/nixpkgs/compare/bdf161ed8d21...6b63c4616790">
Bump the <literal>system.defaultChannel</literal> attribute in
<literal>nixos/modules/misc/version.nix</literal>
</link>
</para>
</listitem>
<listitem>
<para>
<link xlink:href="https://github.com/NixOS/nixpkgs/commit/d6b08acd1ccac0d9d502c4b635e00b04d3387f06">
Update <literal>versionSuffix</literal> in
<literal>nixos/release.nix</literal></link>, use
<literal>git log --format=%an|wc -l</literal> to get the commit
count
</para>
</listitem>
<listitem>
<para>
<literal>echo -n &quot;18.03&quot; &gt; .version</literal> on
master.
</para>
</listitem>
<listitem>
<para>
<link xlink:href="https://github.com/NixOS/nixpkgs/commit/b8a4095003e27659092892a4708bb3698231a842">
Pick a new name for the unstable branch.
</link>
</para>
</listitem>
<listitem>
<para>
Create a new release notes file for the upcoming release + 1, in this
case <literal>rl-1803.xml</literal>.
</para>
</listitem>
<listitem>
<para>
Create two Hydra jobsets: release-17.09 and release-17.09-small with <literal>stableBranch</literal> set to false.
</para>
</listitem>
<listitem>
<para>
Edit changelog at
<literal>nixos/doc/manual/release-notes/rl-1709.xml</literal>
(double check desktop versions are noted)
</para>
<itemizedlist spacing="compact">
<listitem>
<para>
Get all new NixOS modules
<literal>git diff release-17.03..release-17.09 nixos/modules/module-list.nix|grep ^+</literal>
</para>
</listitem>
<listitem>
<para>
Note systemd, kernel, glibc and Nix upgrades.
</para>
</listitem>
</itemizedlist>
</listitem>
</itemizedlist>
</section>
<section xml:id="during-beta">
<title>During Beta</title>
<itemizedlist spacing="compact">
<listitem>
<para>
Monitor the master branch for bugfixes and minor updates
and cherry-pick them to the release branch.
</para>
</listitem>
</itemizedlist>
</section>
<section xml:id="before-the-final-release">
<title>Before the final release</title>
<itemizedlist spacing="compact">
<listitem>
<para>
Re-check that the release notes are complete.
</para>
</listitem>
<listitem>
<para>
Release Nix (currently only Eelco Dolstra can do that).
<link xlink:href="https://github.com/NixOS/nixpkgs/commit/53710c752a85f00658882531bc90a23a3d1287e4">
Make sure fallback is updated.
</link>
</para>
</listitem>
<listitem>
<para>
<link xlink:href="https://github.com/NixOS/nixpkgs/commit/40fd9ae3ac8048758abdcfc7d28a78b5f22fe97e">
Update README.md with new stable NixOS version information.
</link>
</para>
</listitem>
<listitem>
<para>
Change <literal>stableBranch</literal> to true and wait for channel to update.
</para>
</listitem>
</itemizedlist>
</section>
<section xml:id="at-final-release-time">
<title>At final release time</title>
<itemizedlist spacing="compact">
<listitem>
<para>
<literal>git tag -s -a -m &quot;Release 15.09&quot; 15.09</literal>
</para>
</listitem>
<listitem>
<para>
Update http://nixos.org/nixos/download.html and http://nixos.org/nixos/manual in https://github.com/NixOS/nixos-org-configurations
</para>
</listitem>
<listitem>
<para>
Get number of commits for the release:
<literal>git log release-14.04..release-14.12 --format=%an|wc -l</literal>
</para>
</listitem>
<listitem>
<para>
Commits by contributor:
<literal>git log release-14.04..release-14.12 --format=%an|sort|uniq -c|sort -rn</literal>
</para>
</listitem>
<listitem>
<para>
Send an email to nix-dev to announce the release with above information. Best to check how previous email was formulated
to see what needs to be included.
</para>
</listitem>
</itemizedlist>
</section>
</section>
<title>One month before the beta</title>
<section xml:id="release-schedule">
<itemizedlist spacing="compact">
<listitem>
<para>
Send an email to the nix-devel mailinglist as a warning about upcoming
beta "feature freeze" in a month.
</para>
</listitem>
<listitem>
<para>
Discuss with Eelco Dolstra and the community (via IRC, ML) about what
will reach the deadline. Any issue or Pull Request targeting the release
should be included in the release milestone.
</para>
</listitem>
</itemizedlist>
</section>
<section xml:id="at-beta-release-time">
<title>At beta release time</title>
<itemizedlist spacing="compact">
<listitem>
<para>
<link xlink:href="https://github.com/NixOS/nixpkgs/issues/13559">Create
an issue for tracking Zero Hydra Failures progress. ZHF is an effort to
get build failures down to zero.</link>
</para>
</listitem>
<listitem>
<para>
<literal>git tag -a -s -m &quot;Release 17.09-beta&quot; 17.09-beta
&amp;&amp; git push --tags</literal>
</para>
</listitem>
<listitem>
<para>
From the master branch run <literal>git checkout -B
release-17.09</literal>.
</para>
</listitem>
<listitem>
<para>
<link xlink:href="https://github.com/NixOS/nixos-org-configurations/pull/18">
Make sure a channel is created at http://nixos.org/channels/. </link>
</para>
</listitem>
<listitem>
<para>
<link xlink:href="https://github.com/NixOS/nixpkgs/settings/branches">
Let a GitHub nixpkgs admin lock the branch on github for you. (so
developers can’t force push) </link>
</para>
</listitem>
<listitem>
<para>
<link xlink:href="https://github.com/NixOS/nixpkgs/compare/bdf161ed8d21...6b63c4616790">
Bump the <literal>system.defaultChannel</literal> attribute in
<literal>nixos/modules/misc/version.nix</literal> </link>
</para>
</listitem>
<listitem>
<para>
<link xlink:href="https://github.com/NixOS/nixpkgs/commit/d6b08acd1ccac0d9d502c4b635e00b04d3387f06">
Update <literal>versionSuffix</literal> in
<literal>nixos/release.nix</literal></link>, use <literal>git log
--format=%an|wc -l</literal> to get the commit count
</para>
</listitem>
<listitem>
<para>
<literal>echo -n &quot;18.03&quot; &gt; .version</literal> on master.
</para>
</listitem>
<listitem>
<para>
<link xlink:href="https://github.com/NixOS/nixpkgs/commit/b8a4095003e27659092892a4708bb3698231a842">
Pick a new name for the unstable branch. </link>
</para>
</listitem>
<listitem>
<para>
Create a new release notes file for the upcoming release + 1, in this
case <literal>rl-1803.xml</literal>.
</para>
</listitem>
<listitem>
<para>
Create two Hydra jobsets: release-17.09 and release-17.09-small with
<literal>stableBranch</literal> set to false.
</para>
</listitem>
<listitem>
<para>
Edit changelog at
<literal>nixos/doc/manual/release-notes/rl-1709.xml</literal> (double
check desktop versions are noted)
</para>
<itemizedlist spacing="compact">
<listitem>
<para>
Get all new NixOS modules <literal>git diff
release-17.03..release-17.09 nixos/modules/module-list.nix|grep
^+</literal>
</para>
</listitem>
<listitem>
<para>
Note systemd, kernel, glibc and Nix upgrades.
</para>
</listitem>
</itemizedlist>
</listitem>
</itemizedlist>
</section>
<section xml:id="during-beta">
<title>During Beta</title>
<itemizedlist spacing="compact">
<listitem>
<para>
Monitor the master branch for bugfixes and minor updates and cherry-pick
them to the release branch.
</para>
</listitem>
</itemizedlist>
</section>
<section xml:id="before-the-final-release">
<title>Before the final release</title>
<itemizedlist spacing="compact">
<listitem>
<para>
Re-check that the release notes are complete.
</para>
</listitem>
<listitem>
<para>
Release Nix (currently only Eelco Dolstra can do that).
<link xlink:href="https://github.com/NixOS/nixpkgs/commit/53710c752a85f00658882531bc90a23a3d1287e4">
Make sure fallback is updated. </link>
</para>
</listitem>
<listitem>
<para>
<link xlink:href="https://github.com/NixOS/nixpkgs/commit/40fd9ae3ac8048758abdcfc7d28a78b5f22fe97e">
Update README.md with new stable NixOS version information. </link>
</para>
</listitem>
<listitem>
<para>
Change <literal>stableBranch</literal> to true and wait for channel to
update.
</para>
</listitem>
</itemizedlist>
</section>
<section xml:id="at-final-release-time">
<title>At final release time</title>
<itemizedlist spacing="compact">
<listitem>
<para>
<literal>git tag -s -a -m &quot;Release 15.09&quot; 15.09</literal>
</para>
</listitem>
<listitem>
<para>
Update http://nixos.org/nixos/download.html and
http://nixos.org/nixos/manual in
https://github.com/NixOS/nixos-org-configurations
</para>
</listitem>
<listitem>
<para>
Get number of commits for the release: <literal>git log
release-14.04..release-14.12 --format=%an|wc -l</literal>
</para>
</listitem>
<listitem>
<para>
Commits by contributor: <literal>git log release-14.04..release-14.12
--format=%an|sort|uniq -c|sort -rn</literal>
</para>
</listitem>
<listitem>
<para>
Send an email to nix-dev to announce the release with above information.
Best to check how previous email was formulated to see what needs to be
included.
</para>
</listitem>
</itemizedlist>
</section>
</section>
<section xml:id="release-schedule">
<title>Release schedule</title>
<informaltable>
<tgroup cols="2">
<colspec align="left" />
<colspec align="left" />
<thead>
<row>
<entry>
<tgroup cols="2">
<colspec align="left" />
<colspec align="left" />
<thead>
<row>
<entry>
Date
</entry>
<entry>
<entry>
Event
</entry>
</row>
</thead>
<tbody>
<row>
<entry>
</row>
</thead>
<tbody>
<row>
<entry>
2016-07-25
</entry>
<entry>
<entry>
Send email to nix-dev about upcoming branch-off
</entry>
</row>
<row>
<entry>
</row>
<row>
<entry>
2016-09-01
</entry>
<entry>
<literal>release-16.09</literal> branch and corresponding jobsets are created,
<entry><literal>release-16.09</literal> branch and corresponding jobsets are created,
change freeze
</entry>
</row>
<row>
<entry>
</row>
<row>
<entry>
2016-09-30
</entry>
<entry>
<entry>
NixOS 16.09 released
</entry>
</row>
</tbody>
</tgroup>
</row>
</tbody>
</tgroup>
</informaltable>
</section>
</section>
</chapter>

48
nixos/doc/manual/development/replace-modules.xml
View File

@ -3,27 +3,31 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-replace-modules">
<title>Replace Modules</title>
<title>Replace Modules</title>
<para>
Modules that are imported can also be disabled. The option declarations and
config implementation of a disabled module will be ignored, allowing another
to take it's place. This can be used to import a set of modules from another
channel while keeping the rest of the system on a stable release.
</para>
<para>Modules that are imported can also be disabled. The option
declarations and config implementation of a disabled module will be
ignored, allowing another to take it's place. This can be used to
import a set of modules from another channel while keeping the rest
of the system on a stable release.</para>
<para><literal>disabledModules</literal> is a top level attribute like
<para>
<literal>disabledModules</literal> is a top level attribute like
<literal>imports</literal>, <literal>options</literal> and
<literal>config</literal>. It contains a list of modules that will
be disabled. This can either be the full path to the module or a
string with the filename relative to the modules path
(eg. &lt;nixpkgs/nixos/modules&gt; for nixos).
</para>
<literal>config</literal>. It contains a list of modules that will be
disabled. This can either be the full path to the module or a string with the
filename relative to the modules path (eg. &lt;nixpkgs/nixos/modules&gt; for
nixos).
</para>
<para>This example will replace the existing postgresql module with
the version defined in the nixos-unstable channel while keeping the
rest of the modules and packages from the original nixos channel.
This only overrides the module definition, this won't use postgresql
from nixos-unstable unless explicitly configured to do so.</para>
<para>
This example will replace the existing postgresql module with the version
defined in the nixos-unstable channel while keeping the rest of the modules
and packages from the original nixos channel. This only overrides the module
definition, this won't use postgresql from nixos-unstable unless explicitly
configured to do so.
</para>
<programlisting>
{ config, lib, pkgs, ... }:
@ -41,10 +45,11 @@
}
</programlisting>
<para>This example shows how to define a custom module as a
replacement for an existing module. Importing this module will
disable the original module without having to know it's
implementation details.</para>
<para>
This example shows how to define a custom module as a replacement for an
existing module. Importing this module will disable the original module
without having to know it's implementation details.
</para>
<programlisting>
{ config, lib, pkgs, ... }:
@ -71,5 +76,4 @@ in
};
}
</programlisting>
</section>

37
nixos/doc/manual/development/running-nixos-tests-interactively.xml
View File

@ -3,41 +3,38 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-running-nixos-tests">
<title>Running Tests interactively</title>
<para>The test itself can be run interactively. This is
particularly useful when developing or debugging a test:
<title>Running Tests interactively</title>
<para>
The test itself can be run interactively. This is particularly useful when
developing or debugging a test:
<screen>
$ nix-build nixos/tests/login.nix -A driver
$ ./result/bin/nixos-test-driver
starting VDE switch for network 1
&gt;
</screen>
You can then take any Perl statement, e.g.
You can then take any Perl statement, e.g.
<screen>
&gt; startAll
&gt; testScript
&gt; $machine->succeed("touch /tmp/foo")
</screen>
The function <command>testScript</command> executes the entire test script
and drops you back into the test driver command line upon its completion.
This allows you to inspect the state of the VMs after the test (e.g. to debug
the test script).
</para>
The function <command>testScript</command> executes the entire test
script and drops you back into the test driver command line upon its
completion. This allows you to inspect the state of the VMs after the
test (e.g. to debug the test script).</para>
<para>To just start and experiment with the VMs, run:
<para>
To just start and experiment with the VMs, run:
<screen>
$ nix-build nixos/tests/login.nix -A driver
$ ./result/bin/nixos-run-vms
</screen>
The script <command>nixos-run-vms</command> starts the virtual
machines defined by test. The root file system of the VMs is created
on the fly and kept across VM restarts in
<filename>./</filename><varname>hostname</varname><filename>.qcow2</filename>.</para>
The script <command>nixos-run-vms</command> starts the virtual machines
defined by test. The root file system of the VMs is created on the fly and
kept across VM restarts in
<filename>./</filename><varname>hostname</varname><filename>.qcow2</filename>.
</para>
</section>

31
nixos/doc/manual/development/running-nixos-tests.xml
View File

@ -3,20 +3,18 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-running-nixos-tests-interactively">
<title>Running Tests</title>
<title>Running Tests</title>
<para>You can run tests using <command>nix-build</command>. For
example, to run the test <filename
<para>
You can run tests using <command>nix-build</command>. For example, to run the
test
<filename
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/nixos/tests/login.nix">login.nix</filename>,
you just do:
you just do:
<screen>
$ nix-build '&lt;nixpkgs/nixos/tests/login.nix>'
</screen>
or, if you don’t want to rely on <envar>NIX_PATH</envar>:
or, if you don’t want to rely on <envar>NIX_PATH</envar>:
<screen>
$ cd /my/nixpkgs/nixos/tests
$ nix-build login.nix
@ -26,16 +24,13 @@ machine: QEMU running (pid 8841)
…
6 out of 6 tests succeeded
</screen>
After building/downloading all required dependencies, this will
perform a build that starts a QEMU/KVM virtual machine containing a
NixOS system. The virtual machine mounts the Nix store of the host;
this makes VM creation very fast, as no disk image needs to be
created. Afterwards, you can view a pretty-printed log of the test:
After building/downloading all required dependencies, this will perform a
build that starts a QEMU/KVM virtual machine containing a NixOS system. The
virtual machine mounts the Nix store of the host; this makes VM creation very
fast, as no disk image needs to be created. Afterwards, you can view a
pretty-printed log of the test:
<screen>
$ firefox result/log.html
</screen>
</para>
</para>
</section>

113
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View File

@ -3,101 +3,84 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-getting-sources">
<title>Getting the Sources</title>
<para>By default, NixOS’s <command>nixos-rebuild</command> command
uses the NixOS and Nixpkgs sources provided by the
<literal>nixos</literal> channel (kept in
<filename>/nix/var/nix/profiles/per-user/root/channels/nixos</filename>).
To modify NixOS, however, you should check out the latest sources from
Git. This is as follows:
<title>Getting the Sources</title>
<para>
By default, NixOS’s <command>nixos-rebuild</command> command uses the NixOS
and Nixpkgs sources provided by the <literal>nixos</literal> channel (kept in
<filename>/nix/var/nix/profiles/per-user/root/channels/nixos</filename>). To
modify NixOS, however, you should check out the latest sources from Git. This
is as follows:
<screen>
$ git clone git://github.com/NixOS/nixpkgs.git
$ cd nixpkgs
$ git remote add channels git://github.com/NixOS/nixpkgs-channels.git
$ git remote update channels
</screen>
This will check out the latest Nixpkgs sources to
<filename>./nixpkgs</filename> the NixOS sources to
<filename>./nixpkgs/nixos</filename>. (The NixOS source tree lives in
a subdirectory of the Nixpkgs repository.) The remote
<literal>channels</literal> refers to a read-only repository that
tracks the Nixpkgs/NixOS channels (see <xref linkend="sec-upgrading"/>
for more information about channels). Thus, the Git branch
<literal>channels/nixos-17.03</literal> will contain the latest built
and tested version available in the <literal>nixos-17.03</literal>
channel.</para>
<para>It’s often inconvenient to develop directly on the master
branch, since if somebody has just committed (say) a change to GCC,
then the binary cache may not have caught up yet and you’ll have to
rebuild everything from source. So you may want to create a local
branch based on your current NixOS version:
This will check out the latest Nixpkgs sources to
<filename>./nixpkgs</filename> the NixOS sources to
<filename>./nixpkgs/nixos</filename>. (The NixOS source tree lives in a
subdirectory of the Nixpkgs repository.) The remote
<literal>channels</literal> refers to a read-only repository that tracks the
Nixpkgs/NixOS channels (see <xref linkend="sec-upgrading"/> for more
information about channels). Thus, the Git branch
<literal>channels/nixos-17.03</literal> will contain the latest built and
tested version available in the <literal>nixos-17.03</literal> channel.
</para>
<para>
It’s often inconvenient to develop directly on the master branch, since if
somebody has just committed (say) a change to GCC, then the binary cache may
not have caught up yet and you’ll have to rebuild everything from source.
So you may want to create a local branch based on your current NixOS version:
<screen>
$ nixos-version
17.09pre104379.6e0b727 (Hummingbird)
$ git checkout -b local 6e0b727
</screen>
Or, to base your local branch on the latest version available in a
NixOS channel:
Or, to base your local branch on the latest version available in a NixOS
channel:
<screen>
$ git remote update channels
$ git checkout -b local channels/nixos-17.03
</screen>
(Replace <literal>nixos-17.03</literal> with the name of the channel
you want to use.) You can use <command>git merge</command> or
<command>git rebase</command> to keep your local branch in sync with
the channel, e.g.
(Replace <literal>nixos-17.03</literal> with the name of the channel you want
to use.) You can use <command>git merge</command> or <command>git
rebase</command> to keep your local branch in sync with the channel, e.g.
<screen>
$ git remote update channels
$ git merge channels/nixos-17.03
</screen>
You can use <command>git cherry-pick</command> to copy commits from
your local branch to the upstream branch.</para>
<para>If you want to rebuild your system using your (modified)
sources, you need to tell <command>nixos-rebuild</command> about them
using the <option>-I</option> flag:
You can use <command>git cherry-pick</command> to copy commits from your
local branch to the upstream branch.
</para>
<para>
If you want to rebuild your system using your (modified) sources, you need to
tell <command>nixos-rebuild</command> about them using the
<option>-I</option> flag:
<screen>
# nixos-rebuild switch -I nixpkgs=<replaceable>/my/sources</replaceable>/nixpkgs
</screen>
</para>
<para>If you want <command>nix-env</command> to use the expressions in
<replaceable>/my/sources</replaceable>, use <command>nix-env -f
<replaceable>/my/sources</replaceable>/nixpkgs</command>, or change
the default by adding a symlink in
<filename>~/.nix-defexpr</filename>:
</para>
<para>
If you want <command>nix-env</command> to use the expressions in
<replaceable>/my/sources</replaceable>, use <command>nix-env -f
<replaceable>/my/sources</replaceable>/nixpkgs</command>, or change the
default by adding a symlink in <filename>~/.nix-defexpr</filename>:
<screen>
$ ln -s <replaceable>/my/sources</replaceable>/nixpkgs ~/.nix-defexpr/nixpkgs
</screen>
You may want to delete the symlink
<filename>~/.nix-defexpr/channels_root</filename> to prevent root’s
NixOS channel from clashing with your own tree (this may break the
command-not-found utility though). If you want to go back to the default
state, you may just remove the <filename>~/.nix-defexpr</filename>
directory completely, log out and log in again and it should have been
recreated with a link to the root channels.</para>
You may want to delete the symlink
<filename>~/.nix-defexpr/channels_root</filename> to prevent root’s NixOS
channel from clashing with your own tree (this may break the
command-not-found utility though). If you want to go back to the default
state, you may just remove the <filename>~/.nix-defexpr</filename> directory
completely, log out and log in again and it should have been recreated with a
link to the root channels.
</para>
<!-- FIXME: not sure what this means.
<para>You should not pass the base directory
<filename><replaceable>/my/sources</replaceable></filename>
to <command>nix-env</command>, as it will break after interpreting expressions
in <filename>nixos/</filename> as packages.</para>
-->
</chapter>

21
nixos/doc/manual/development/testing-installer.xml
View File

@ -3,27 +3,20 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="ch-testing-installer">
<title>Testing the Installer</title>
<para>Building, burning, and booting from an installation CD is rather
tedious, so here is a quick way to see if the installer works
properly:
<title>Testing the Installer</title>
<para>
Building, burning, and booting from an installation CD is rather tedious, so
here is a quick way to see if the installer works properly:
<screen>
# mount -t tmpfs none /mnt
# nixos-generate-config --root /mnt
$ nix-build '&lt;nixpkgs/nixos>' -A config.system.build.nixos-install
# ./result/bin/nixos-install</screen>
To start a login shell in the new NixOS installation in
<filename>/mnt</filename>:
To start a login shell in the new NixOS installation in
<filename>/mnt</filename>:
<screen>
$ nix-build '&lt;nixpkgs/nixos>' -A config.system.build.nixos-enter
# ./result/bin/nixos-enter
</screen>
</para>
</para>
</chapter>

252
nixos/doc/manual/development/writing-documentation.xml
View File

@ -3,157 +3,147 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-writing-documentation">
<title>Writing NixOS Documentation</title>
<para>
As NixOS grows, so too does the need for a catalogue and explanation of its
extensive functionality. Collecting pertinent information from disparate
sources and presenting it in an accessible style would be a worthy
contribution to the project.
</para>
<section>
<title>Building the Manual</title>
<title>Writing NixOS Documentation</title>
<para>
The DocBook sources of the <xref linkend="book-nixos-manual"/> are in the
<link xlink:href="https://github.com/NixOS/nixpkgs/tree/master/nixos/doc/manual"><filename>nixos/doc/manual</filename></link>
subdirectory of the Nixpkgs repository.
</para>
<para>
As NixOS grows, so too does the need for a catalogue and explanation
of its extensive functionality. Collecting pertinent information
from disparate sources and presenting it in an accessible style
would be a worthy contribution to the project.
</para>
<section>
<title>Building the Manual</title>
<para>
The DocBook sources of the <xref linkend="book-nixos-manual"/> are in the
<link xlink:href="https://github.com/NixOS/nixpkgs/tree/master/nixos/doc/manual"><filename>nixos/doc/manual</filename></link>
subdirectory of the Nixpkgs repository.
</para>
<para>
You can quickly validate your edits with <command>make</command>:
</para>
<para>
You can quickly validate your edits with <command>make</command>:
</para>
<screen>
$ cd /path/to/nixpkgs/nixos/doc/manual
$ make
</screen>
<para>
Once you are done making modifications to the manual, it's important
to build it before committing. You can do that as follows:
</para>
<para>
Once you are done making modifications to the manual, it's important to
build it before committing. You can do that as follows:
</para>
<screen>nix-build nixos/release.nix -A manual.x86_64-linux</screen>
<para>
When this command successfully finishes, it will tell you where the
manual got generated. The HTML will be accessible through the
<filename>result</filename> symlink at
<filename>./result/share/doc/nixos/index.html</filename>.
</para>
</section>
<para>
When this command successfully finishes, it will tell you where the manual
got generated. The HTML will be accessible through the
<filename>result</filename> symlink at
<filename>./result/share/doc/nixos/index.html</filename>.
</para>
</section>
<section>
<title>Editing DocBook XML</title>
<section>
<title>Editing DocBook XML</title>
<para>
For general information on how to write in DocBook, see
<link xlink:href="http://www.docbook.org/tdg5/en/html/docbook.html"> DocBook
5: The Definitive Guide</link>.
</para>
<para>
For general information on how to write in DocBook, see
<link xlink:href="http://www.docbook.org/tdg5/en/html/docbook.html">
DocBook 5: The Definitive Guide</link>.
</para>
<para>
Emacs nXML Mode is very helpful for editing DocBook XML because it validates
the document as you write, and precisely locates errors. To use it, see
<xref linkend="sec-emacs-docbook-xml"/>.
</para>
<para>
Emacs nXML Mode is very helpful for editing DocBook XML because it
validates the document as you write, and precisely locates
errors. To use it, see <xref linkend="sec-emacs-docbook-xml"/>.
</para>
<para>
<link xlink:href="http://pandoc.org">Pandoc</link> can generate
DocBook XML from a multitude of formats, which makes a good starting
point.
<example xml:id="ex-pandoc-xml-conv">
<para>
<link xlink:href="http://pandoc.org">Pandoc</link> can generate DocBook XML
from a multitude of formats, which makes a good starting point.
<example xml:id="ex-pandoc-xml-conv">
<title>Pandoc invocation to convert GitHub-Flavoured MarkDown to DocBook 5 XML</title>
<screen>pandoc -f markdown_github -t docbook5 docs.md -o my-section.md</screen>
</example>
<screen>pandoc -f markdown_github -t docbook5 docs.md -o my-section.md</screen>
</example>
Pandoc can also quickly convert a single <filename>section.xml</filename> to
HTML, which is helpful when drafting.
</para>
Pandoc can also quickly convert a single
<filename>section.xml</filename> to HTML, which is helpful when
drafting.
</para>
<para>
Sometimes writing valid DocBook is simply too difficult. In this
case, submit your documentation updates in a <link
<para>
Sometimes writing valid DocBook is simply too difficult. In this case,
submit your documentation updates in a
<link
xlink:href="https://github.com/NixOS/nixpkgs/issues/new">GitHub
Issue</link> and someone will handle the conversion to XML for you.
</para>
</section>
Issue</link> and someone will handle the conversion to XML for you.
</para>
</section>
<section>
<title>Creating a Topic</title>
<section>
<title>Creating a Topic</title>
<para>
You can use an existing topic as a basis for the new topic or create a topic
from scratch.
</para>
<para>
You can use an existing topic as a basis for the new topic or create a topic from scratch.
</para>
<para>
Keep the following guidelines in mind when you create and add a topic:
<itemizedlist>
<listitem>
<para>
The NixOS
<link xlink:href="http://www.docbook.org/tdg5/en/html/book.html"><tag>book</tag></link>
element is in <filename>nixos/doc/manual/manual.xml</filename>. It
includes several
<link xlink:href="http://www.docbook.org/tdg5/en/html/book.html"><tag>part</tag>s</link>
which are in subdirectories.
</para>
</listitem>
<listitem>
<para>
Store the topic file in the same directory as the <tag>part</tag> to
which it belongs. If your topic is about configuring a NixOS module, then
the XML file can be stored alongside the module definition
<filename>nix</filename> file.
</para>
</listitem>
<listitem>
<para>
If you include multiple words in the file name, separate the words with a
dash. For example: <filename>ipv6-config.xml</filename>.
</para>
</listitem>
<listitem>
<para>
Make sure that the <tag>xml:id</tag> value is unique. You can use
abbreviations if the ID is too long. For example:
<varname>nixos-config</varname>.
</para>
</listitem>
<listitem>
<para>
Determine whether your topic is a chapter or a section. If you are
unsure, open an existing topic file and check whether the main element is
chapter or section.
</para>
</listitem>
</itemizedlist>
</para>
</section>
<section>
<title>Adding a Topic to the Book</title>
<para>
Keep the following guidelines in mind when you create and add a topic:
<para>
Open the parent XML file and add an <varname>xi:include</varname> element to
the list of chapters with the file name of the topic that you created. If
you created a <tag>section</tag>, you add the file to the <tag>chapter</tag>
file. If you created a <tag>chapter</tag>, you add the file to the
<tag>part</tag> file.
</para>
<itemizedlist>
<listitem><para>
The NixOS <link xlink:href="http://www.docbook.org/tdg5/en/html/book.html"><tag>book</tag></link>
element is in <filename>nixos/doc/manual/manual.xml</filename>.
It includes several
<link xlink:href="http://www.docbook.org/tdg5/en/html/book.html"><tag>part</tag>s</link>
which are in subdirectories.
</para></listitem>
<listitem><para>
Store the topic file in the same directory as the <tag>part</tag>
to which it belongs. If your topic is about configuring a NixOS
module, then the XML file can be stored alongside the module
definition <filename>nix</filename> file.
</para></listitem>
<listitem><para>
If you include multiple words in the file name, separate the words
with a dash. For example: <filename>ipv6-config.xml</filename>.
</para></listitem>
<listitem><para>
Make sure that the <tag>xml:id</tag> value is unique. You can use
abbreviations if the ID is too long. For example:
<varname>nixos-config</varname>.
</para></listitem>
<listitem><para>
Determine whether your topic is a chapter or a section. If you are
unsure, open an existing topic file and check whether the main
element is chapter or section.
</para></listitem>
</itemizedlist>
</para>
</section>
<section>
<title>Adding a Topic to the Book</title>
<para>
Open the parent XML file and add an <varname>xi:include</varname>
element to the list of chapters with the file name of the topic that
you created. If you created a <tag>section</tag>, you add the file to
the <tag>chapter</tag> file. If you created a <tag>chapter</tag>, you
add the file to the <tag>part</tag> file.
</para>
<para>
If the topic is about configuring a NixOS module, it can be
automatically included in the manual by using the
<varname>meta.doc</varname> attribute. See <xref
<para>
If the topic is about configuring a NixOS module, it can be automatically
included in the manual by using the <varname>meta.doc</varname> attribute.
See <xref
linkend="sec-meta-attributes"/> for an explanation.
</para>
</section>
</para>
</section>
</chapter>

190
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@ -3,52 +3,54 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-writing-modules">
<title>Writing NixOS Modules</title>
<para>NixOS has a modular system for declarative configuration. This
system combines multiple <emphasis>modules</emphasis> to produce the
full system configuration. One of the modules that constitute the
configuration is <filename>/etc/nixos/configuration.nix</filename>.
Most of the others live in the <link
<title>Writing NixOS Modules</title>
<para>
NixOS has a modular system for declarative configuration. This system
combines multiple <emphasis>modules</emphasis> to produce the full system
configuration. One of the modules that constitute the configuration is
<filename>/etc/nixos/configuration.nix</filename>. Most of the others live in
the
<link
xlink:href="https://github.com/NixOS/nixpkgs/tree/master/nixos/modules"><filename>nixos/modules</filename></link>
subdirectory of the Nixpkgs tree.</para>
<para>Each NixOS module is a file that handles one logical aspect of
the configuration, such as a specific kind of hardware, a service, or
network settings. A module configuration does not have to handle
everything from scratch; it can use the functionality provided by
other modules for its implementation. Thus a module can
<emphasis>declare</emphasis> options that can be used by other
modules, and conversely can <emphasis>define</emphasis> options
provided by other modules in its own implementation. For example, the
module <link
subdirectory of the Nixpkgs tree.
</para>
<para>
Each NixOS module is a file that handles one logical aspect of the
configuration, such as a specific kind of hardware, a service, or network
settings. A module configuration does not have to handle everything from
scratch; it can use the functionality provided by other modules for its
implementation. Thus a module can <emphasis>declare</emphasis> options that
can be used by other modules, and conversely can <emphasis>define</emphasis>
options provided by other modules in its own implementation. For example, the
module
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/security/pam.nix"><filename>pam.nix</filename></link>
declares the option <option>security.pam.services</option> that allows
other modules (e.g. <link
declares the option <option>security.pam.services</option> that allows other
modules (e.g.
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/services/networking/ssh/sshd.nix"><filename>sshd.nix</filename></link>)
to define PAM services; and it defines the option
<option>environment.etc</option> (declared by <link
to define PAM services; and it defines the option
<option>environment.etc</option> (declared by
<link
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/system/etc/etc.nix"><filename>etc.nix</filename></link>)
to cause files to be created in
<filename>/etc/pam.d</filename>.</para>
<para xml:id="para-module-syn">In <xref
to cause files to be created in <filename>/etc/pam.d</filename>.
</para>
<para xml:id="para-module-syn">
In <xref
linkend="sec-configuration-syntax"/>, we saw the following structure
of NixOS modules:
of NixOS modules:
<programlisting>
{ config, pkgs, ... }:
{ <replaceable>option definitions</replaceable>
}
</programlisting>
This is actually an <emphasis>abbreviated</emphasis> form of module
that only defines options, but does not declare any. The structure of
full NixOS modules is shown in <xref linkend='ex-module-syntax' />.</para>
<example xml:id='ex-module-syntax'><title>Structure of NixOS Modules</title>
This is actually an <emphasis>abbreviated</emphasis> form of module that only
defines options, but does not declare any. The structure of full NixOS
modules is shown in <xref linkend='ex-module-syntax' />.
</para>
<example xml:id='ex-module-syntax'>
<title>Structure of NixOS Modules</title>
<programlisting>
{ config, pkgs, ... }: <co xml:id='module-syntax-1' />
@ -65,56 +67,56 @@ full NixOS modules is shown in <xref linkend='ex-module-syntax' />.</para>
<replaceable>option definitions</replaceable> <co xml:id='module-syntax-4' />
};
}</programlisting>
</example>
<para>The meaning of each part is as follows.
<calloutlist>
<callout arearefs='module-syntax-1'>
<para>This line makes the current Nix expression a function. The
variable <varname>pkgs</varname> contains Nixpkgs, while
<varname>config</varname> contains the full system configuration.
This line can be omitted if there is no reference to
<varname>pkgs</varname> and <varname>config</varname> inside the
module.</para>
</callout>
<callout arearefs='module-syntax-2'>
<para>This list enumerates the paths to other NixOS modules that
should be included in the evaluation of the system configuration.
A default set of modules is defined in the file
<filename>modules/module-list.nix</filename>. These don't need to
be added in the import list.</para>
</callout>
<callout arearefs='module-syntax-3'>
<para>The attribute <varname>options</varname> is a nested set of
<emphasis>option declarations</emphasis> (described below).</para>
</callout>
<callout arearefs='module-syntax-4'>
<para>The attribute <varname>config</varname> is a nested set of
<emphasis>option definitions</emphasis> (also described
below).</para>
</callout>
</calloutlist>
</para>
<para><xref linkend='locate-example' /> shows a module that handles
the regular update of the “locate” database, an index of all files in
the file system. This module declares two options that can be defined
by other modules (typically the user’s
<filename>configuration.nix</filename>):
<option>services.locate.enable</option> (whether the database should
be updated) and <option>services.locate.interval</option> (when the
update should be done). It implements its functionality by defining
two options declared by other modules:
<option>systemd.services</option> (the set of all systemd services)
and <option>systemd.timers</option> (the list of commands to be
executed periodically by <command>systemd</command>).</para>
<example xml:id='locate-example'><title>NixOS Module for the “locate” Service</title>
</example>
<para>
The meaning of each part is as follows.
<calloutlist>
<callout arearefs='module-syntax-1'>
<para>
This line makes the current Nix expression a function. The variable
<varname>pkgs</varname> contains Nixpkgs, while <varname>config</varname>
contains the full system configuration. This line can be omitted if there
is no reference to <varname>pkgs</varname> and <varname>config</varname>
inside the module.
</para>
</callout>
<callout arearefs='module-syntax-2'>
<para>
This list enumerates the paths to other NixOS modules that should be
included in the evaluation of the system configuration. A default set of
modules is defined in the file
<filename>modules/module-list.nix</filename>. These don't need to be added
in the import list.
</para>
</callout>
<callout arearefs='module-syntax-3'>
<para>
The attribute <varname>options</varname> is a nested set of
<emphasis>option declarations</emphasis> (described below).
</para>
</callout>
<callout arearefs='module-syntax-4'>
<para>
The attribute <varname>config</varname> is a nested set of
<emphasis>option definitions</emphasis> (also described below).
</para>
</callout>
</calloutlist>
</para>
<para>
<xref linkend='locate-example' /> shows a module that handles the regular
update of the “locate” database, an index of all files in the file
system. This module declares two options that can be defined by other modules
(typically the user’s <filename>configuration.nix</filename>):
<option>services.locate.enable</option> (whether the database should be
updated) and <option>services.locate.interval</option> (when the update
should be done). It implements its functionality by defining two options
declared by other modules: <option>systemd.services</option> (the set of all
systemd services) and <option>systemd.timers</option> (the list of commands
to be executed periodically by <command>systemd</command>).
</para>
<example xml:id='locate-example'>
<title>NixOS Module for the “locate” Service</title>
<programlisting>
{ config, lib, pkgs, ... }:
@ -173,14 +175,12 @@ in {
};
}
</programlisting>
</example>
<xi:include href="option-declarations.xml" />
<xi:include href="option-types.xml" />
<xi:include href="option-def.xml" />
<xi:include href="assertions.xml" />
<xi:include href="meta-attributes.xml" />
<xi:include href="importing-modules.xml" />
<xi:include href="replace-modules.xml" />
</example>
<xi:include href="option-declarations.xml" />
<xi:include href="option-types.xml" />
<xi:include href="option-def.xml" />
<xi:include href="assertions.xml" />
<xi:include href="meta-attributes.xml" />
<xi:include href="importing-modules.xml" />
<xi:include href="replace-modules.xml" />
</chapter>

588
nixos/doc/manual/development/writing-nixos-tests.xml
View File

@ -3,11 +3,10 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-writing-nixos-tests">
<title>Writing Tests</title>
<title>Writing Tests</title>
<para>A NixOS test is a Nix expression that has the following structure:
<para>
A NixOS test is a Nix expression that has the following structure:
<programlisting>
import ./make-test.nix {
@ -32,277 +31,364 @@ import ./make-test.nix {
'';
}
</programlisting>
The attribute <literal>testScript</literal> is a bit of Perl code that
executes the test (described below). During the test, it will start
one or more virtual machines, the configuration of which is described
by the attribute <literal>machine</literal> (if you need only one
machine in your test) or by the attribute <literal>nodes</literal> (if
you need multiple machines). For instance, <filename
The attribute <literal>testScript</literal> is a bit of Perl code that
executes the test (described below). During the test, it will start one or
more virtual machines, the configuration of which is described by the
attribute <literal>machine</literal> (if you need only one machine in your
test) or by the attribute <literal>nodes</literal> (if you need multiple
machines). For instance,
<filename
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/nixos/tests/login.nix">login.nix</filename>
only needs a single machine to test whether users can log in on the
virtual console, whether device ownership is correctly maintained when
switching between consoles, and so on. On the other hand, <filename
only needs a single machine to test whether users can log in on the virtual
console, whether device ownership is correctly maintained when switching
between consoles, and so on. On the other hand,
<filename
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/nixos/tests/nfs.nix">nfs.nix</filename>,
which tests NFS client and server functionality in the Linux kernel
(including whether locks are maintained across server crashes),
requires three machines: a server and two clients.</para>
<para>There are a few special NixOS configuration options for test
VMs:
which tests NFS client and server functionality in the Linux kernel
(including whether locks are maintained across server crashes), requires
three machines: a server and two clients.
</para>
<para>
There are a few special NixOS configuration options for test VMs:
<!-- FIXME: would be nice to generate this automatically. -->
<variablelist>
<varlistentry>
<term><option>virtualisation.memorySize</option></term>
<listitem><para>The memory of the VM in
megabytes.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>virtualisation.vlans</option></term>
<listitem><para>The virtual networks to which the VM is
connected. See <filename
<variablelist>
<varlistentry>
<term><option>virtualisation.memorySize</option>
</term>
<listitem>
<para>
The memory of the VM in megabytes.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>virtualisation.vlans</option>
</term>
<listitem>
<para>
The virtual networks to which the VM is connected. See
<filename
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/nixos/tests/nat.nix">nat.nix</filename>
for an example.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>virtualisation.writableStore</option></term>
<listitem><para>By default, the Nix store in the VM is not
writable. If you enable this option, a writable union file system
is mounted on top of the Nix store to make it appear
writable. This is necessary for tests that run Nix operations that
modify the store.</para></listitem>
</varlistentry>
</variablelist>
For more options, see the module <filename
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix">qemu-vm.nix</filename>.</para>
<para>The test script is a sequence of Perl statements that perform
various actions, such as starting VMs, executing commands in the VMs,
and so on. Each virtual machine is represented as an object stored in
the variable <literal>$<replaceable>name</replaceable></literal>,
where <replaceable>name</replaceable> is the identifier of the machine
(which is just <literal>machine</literal> if you didn’t specify
multiple machines using the <literal>nodes</literal> attribute). For
instance, the following starts the machine, waits until it has
finished booting, then executes a command and checks that the output
is more-or-less correct:
for an example.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>virtualisation.writableStore</option>
</term>
<listitem>
<para>
By default, the Nix store in the VM is not writable. If you enable this
option, a writable union file system is mounted on top of the Nix store
to make it appear writable. This is necessary for tests that run Nix
operations that modify the store.
</para>
</listitem>
</varlistentry>
</variablelist>
For more options, see the module
<filename
xlink:href="https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/virtualisation/qemu-vm.nix">qemu-vm.nix</filename>.
</para>
<para>
The test script is a sequence of Perl statements that perform various
actions, such as starting VMs, executing commands in the VMs, and so on. Each
virtual machine is represented as an object stored in the variable
<literal>$<replaceable>name</replaceable></literal>, where
<replaceable>name</replaceable> is the identifier of the machine (which is
just <literal>machine</literal> if you didn’t specify multiple machines
using the <literal>nodes</literal> attribute). For instance, the following
starts the machine, waits until it has finished booting, then executes a
command and checks that the output is more-or-less correct:
<programlisting>
$machine->start;
$machine->waitForUnit("default.target");
$machine->succeed("uname") =~ /Linux/;
</programlisting>
The first line is actually unnecessary; machines are implicitly
started when you first execute an action on them (such as
<literal>waitForUnit</literal> or <literal>succeed</literal>). If you
have multiple machines, you can speed up the test by starting them in
parallel:
The first line is actually unnecessary; machines are implicitly started when
you first execute an action on them (such as <literal>waitForUnit</literal>
or <literal>succeed</literal>). If you have multiple machines, you can speed
up the test by starting them in parallel:
<programlisting>
startAll;
</programlisting>
</para>
</para>
<para>The following methods are available on machine objects:
<variablelist>
<varlistentry>
<term><methodname>start</methodname></term>
<listitem><para>Start the virtual machine. This method is
asynchronous — it does not wait for the machine to finish
booting.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>shutdown</methodname></term>
<listitem><para>Shut down the machine, waiting for the VM to
exit.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>crash</methodname></term>
<listitem><para>Simulate a sudden power failure, by telling the VM
to exit immediately.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>block</methodname></term>
<listitem><para>Simulate unplugging the Ethernet cable that
connects the machine to the other machines.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>unblock</methodname></term>
<listitem><para>Undo the effect of
<methodname>block</methodname>.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>screenshot</methodname></term>
<listitem><para>Take a picture of the display of the virtual
machine, in PNG format. The screenshot is linked from the HTML
log.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>getScreenText</methodname></term>
<listitem><para>Return a textual representation of what is currently
visible on the machine's screen using optical character
recognition.</para>
<note><para>This requires passing <option>enableOCR</option> to the test
attribute set.</para></note></listitem>
</varlistentry>
<varlistentry>
<term><methodname>sendMonitorCommand</methodname></term>
<listitem><para>Send a command to the QEMU monitor. This is rarely
used, but allows doing stuff such as attaching virtual USB disks
to a running machine.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>sendKeys</methodname></term>
<listitem><para>Simulate pressing keys on the virtual keyboard,
e.g., <literal>sendKeys("ctrl-alt-delete")</literal>.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>sendChars</methodname></term>
<listitem><para>Simulate typing a sequence of characters on the
virtual keyboard, e.g., <literal>sendKeys("foobar\n")</literal>
will type the string <literal>foobar</literal> followed by the
Enter key.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>execute</methodname></term>
<listitem><para>Execute a shell command, returning a list
<literal>(<replaceable>status</replaceable>,
<replaceable>stdout</replaceable>)</literal>.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>succeed</methodname></term>
<listitem><para>Execute a shell command, raising an exception if
the exit status is not zero, otherwise returning the standard
output.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>fail</methodname></term>
<listitem><para>Like <methodname>succeed</methodname>, but raising
an exception if the command returns a zero status.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitUntilSucceeds</methodname></term>
<listitem><para>Repeat a shell command with 1-second intervals
until it succeeds.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitUntilFails</methodname></term>
<listitem><para>Repeat a shell command with 1-second intervals
until it fails.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitForUnit</methodname></term>
<listitem><para>Wait until the specified systemd unit has reached
the “active” state.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitForFile</methodname></term>
<listitem><para>Wait until the specified file
exists.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitForOpenPort</methodname></term>
<listitem><para>Wait until a process is listening on the given TCP
port (on <literal>localhost</literal>, at least).</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitForClosedPort</methodname></term>
<listitem><para>Wait until nobody is listening on the given TCP
port.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitForX</methodname></term>
<listitem><para>Wait until the X11 server is accepting
connections.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitForText</methodname></term>
<listitem><para>Wait until the supplied regular expressions matches
the textual contents of the screen by using optical character recognition
(see <methodname>getScreenText</methodname>).</para>
<note><para>This requires passing <option>enableOCR</option> to the test
attribute set.</para></note></listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitForWindow</methodname></term>
<listitem><para>Wait until an X11 window has appeared whose name
matches the given regular expression, e.g.,
<literal>waitForWindow(qr/Terminal/)</literal>.</para></listitem>
</varlistentry>
<varlistentry>
<term><methodname>copyFileFromHost</methodname></term>
<listitem><para>Copies a file from host to machine, e.g.,
<literal>copyFileFromHost("myfile", "/etc/my/important/file")</literal>.</para>
<para>The first argument is the file on the host. The file needs to be
accessible while building the nix derivation. The second argument is
the location of the file on the machine.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>systemctl</methodname></term>
<para>
The following methods are available on machine objects:
<variablelist>
<varlistentry>
<term><methodname>start</methodname>
</term>
<listitem>
<para>Runs <literal>systemctl</literal> commands with optional support for
<literal>systemctl --user</literal></para>
<para>
<programlisting>
<para>
Start the virtual machine. This method is asynchronous — it does not
wait for the machine to finish booting.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>shutdown</methodname>
</term>
<listitem>
<para>
Shut down the machine, waiting for the VM to exit.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>crash</methodname>
</term>
<listitem>
<para>
Simulate a sudden power failure, by telling the VM to exit immediately.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>block</methodname>
</term>
<listitem>
<para>
Simulate unplugging the Ethernet cable that connects the machine to the
other machines.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>unblock</methodname>
</term>
<listitem>
<para>
Undo the effect of <methodname>block</methodname>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>screenshot</methodname>
</term>
<listitem>
<para>
Take a picture of the display of the virtual machine, in PNG format. The
screenshot is linked from the HTML log.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>getScreenText</methodname>
</term>
<listitem>
<para>
Return a textual representation of what is currently visible on the
machine's screen using optical character recognition.
</para>
<note>
<para>
This requires passing <option>enableOCR</option> to the test attribute
set.
</para>
</note>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>sendMonitorCommand</methodname>
</term>
<listitem>
<para>
Send a command to the QEMU monitor. This is rarely used, but allows doing
stuff such as attaching virtual USB disks to a running machine.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>sendKeys</methodname>
</term>
<listitem>
<para>
Simulate pressing keys on the virtual keyboard, e.g.,
<literal>sendKeys("ctrl-alt-delete")</literal>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>sendChars</methodname>
</term>
<listitem>
<para>
Simulate typing a sequence of characters on the virtual keyboard, e.g.,
<literal>sendKeys("foobar\n")</literal> will type the string
<literal>foobar</literal> followed by the Enter key.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>execute</methodname>
</term>
<listitem>
<para>
Execute a shell command, returning a list
<literal>(<replaceable>status</replaceable>,
<replaceable>stdout</replaceable>)</literal>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>succeed</methodname>
</term>
<listitem>
<para>
Execute a shell command, raising an exception if the exit status is not
zero, otherwise returning the standard output.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>fail</methodname>
</term>
<listitem>
<para>
Like <methodname>succeed</methodname>, but raising an exception if the
command returns a zero status.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitUntilSucceeds</methodname>
</term>
<listitem>
<para>
Repeat a shell command with 1-second intervals until it succeeds.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitUntilFails</methodname>
</term>
<listitem>
<para>
Repeat a shell command with 1-second intervals until it fails.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitForUnit</methodname>
</term>
<listitem>
<para>
Wait until the specified systemd unit has reached the “active” state.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitForFile</methodname>
</term>
<listitem>
<para>
Wait until the specified file exists.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitForOpenPort</methodname>
</term>
<listitem>
<para>
Wait until a process is listening on the given TCP port (on
<literal>localhost</literal>, at least).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitForClosedPort</methodname>
</term>
<listitem>
<para>
Wait until nobody is listening on the given TCP port.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitForX</methodname>
</term>
<listitem>
<para>
Wait until the X11 server is accepting connections.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitForText</methodname>
</term>
<listitem>
<para>
Wait until the supplied regular expressions matches the textual contents
of the screen by using optical character recognition (see
<methodname>getScreenText</methodname>).
</para>
<note>
<para>
This requires passing <option>enableOCR</option> to the test attribute
set.
</para>
</note>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>waitForWindow</methodname>
</term>
<listitem>
<para>
Wait until an X11 window has appeared whose name matches the given
regular expression, e.g., <literal>waitForWindow(qr/Terminal/)</literal>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>copyFileFromHost</methodname>
</term>
<listitem>
<para>
Copies a file from host to machine, e.g.,
<literal>copyFileFromHost("myfile", "/etc/my/important/file")</literal>.
</para>
<para>
The first argument is the file on the host. The file needs to be
accessible while building the nix derivation. The second argument is the
location of the file on the machine.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><methodname>systemctl</methodname>
</term>
<listitem>
<para>
Runs <literal>systemctl</literal> commands with optional support for
<literal>systemctl --user</literal>
</para>
<para>
<programlisting>
$machine->systemctl("list-jobs --no-pager"); // runs `systemctl list-jobs --no-pager`
$machine->systemctl("list-jobs --no-pager", "any-user"); // spawns a shell for `any-user` and runs `systemctl --user list-jobs --no-pager`
</programlisting>
</para>
</para>
</listitem>
</varlistentry>
</varlistentry>
</variablelist>
</para>
</variablelist>
</para>
<para>
To test user units declared by <literal>systemd.user.services</literal> the optional <literal>$user</literal>
argument can be used:
<programlisting>
<para>
To test user units declared by <literal>systemd.user.services</literal> the
optional <literal>$user</literal> argument can be used:
<programlisting>
$machine->start;
$machine->waitForX;
$machine->waitForUnit("xautolock.service", "x-session-user");
</programlisting>
This applies to <literal>systemctl</literal>, <literal>getUnitInfo</literal>,
<literal>waitForUnit</literal>, <literal>startJob</literal>
and <literal>stopJob</literal>.
</para>
<literal>waitForUnit</literal>, <literal>startJob</literal> and
<literal>stopJob</literal>.
</para>
</section>

131
nixos/doc/manual/installation/changing-config.xml
View File

@ -2,101 +2,84 @@
xmlns:xlink="http://www.w3.org/1999/xlink"
version="5.0"
xml:id="sec-changing-config">
<title>Changing the Configuration</title>
<para>The file <filename>/etc/nixos/configuration.nix</filename>
contains the current configuration of your machine. Whenever you’ve
<link linkend="ch-configuration">changed something</link> in that file, you should do
<title>Changing the Configuration</title>
<para>
The file <filename>/etc/nixos/configuration.nix</filename> contains the
current configuration of your machine. Whenever you’ve
<link linkend="ch-configuration">changed something</link> in that file, you
should do
<screen>
# nixos-rebuild switch</screen>
to build the new configuration, make it the default configuration for
booting, and try to realise the configuration in the running system
(e.g., by restarting system services).</para>
<warning><para>These commands must be executed as root, so you should
either run them from a root shell or by prefixing them with
<literal>sudo -i</literal>.</para></warning>
<para>You can also do
to build the new configuration, make it the default configuration for
booting, and try to realise the configuration in the running system (e.g., by
restarting system services).
</para>
<warning>
<para>
These commands must be executed as root, so you should either run them from
a root shell or by prefixing them with <literal>sudo -i</literal>.
</para>
</warning>
<para>
You can also do
<screen>
# nixos-rebuild test</screen>
to build the configuration and switch the running system to it, but
without making it the boot default. So if (say) the configuration
locks up your machine, you can just reboot to get back to a working
configuration.</para>
<para>There is also
to build the configuration and switch the running system to it, but without
making it the boot default. So if (say) the configuration locks up your
machine, you can just reboot to get back to a working configuration.
</para>
<para>
There is also
<screen>
# nixos-rebuild boot</screen>
to build the configuration and make it the boot default, but not
switch to it now (so it will only take effect after the next
reboot).</para>
<para>You can make your configuration show up in a different submenu
of the GRUB 2 boot screen by giving it a different <emphasis>profile
name</emphasis>, e.g.
to build the configuration and make it the boot default, but not switch to it
now (so it will only take effect after the next reboot).
</para>
<para>
You can make your configuration show up in a different submenu of the GRUB 2
boot screen by giving it a different <emphasis>profile name</emphasis>, e.g.
<screen>
# nixos-rebuild switch -p test </screen>
which causes the new configuration (and previous ones created using
<literal>-p test</literal>) to show up in the GRUB submenu “NixOS -
Profile 'test'”. This can be useful to separate test configurations
from “stable” configurations.</para>
<para>Finally, you can do
which causes the new configuration (and previous ones created using
<literal>-p test</literal>) to show up in the GRUB submenu “NixOS - Profile
'test'”. This can be useful to separate test configurations from
“stable” configurations.
</para>
<para>
Finally, you can do
<screen>
$ nixos-rebuild build</screen>
to build the configuration but nothing more. This is useful to see
whether everything compiles cleanly.</para>
<para>If you have a machine that supports hardware virtualisation, you
can also test the new configuration in a sandbox by building and
running a QEMU <emphasis>virtual machine</emphasis> that contains the
desired configuration. Just do
to build the configuration but nothing more. This is useful to see whether
everything compiles cleanly.
</para>
<para>
If you have a machine that supports hardware virtualisation, you can also
test the new configuration in a sandbox by building and running a QEMU
<emphasis>virtual machine</emphasis> that contains the desired configuration.
Just do
<screen>
$ nixos-rebuild build-vm
$ ./result/bin/run-*-vm
</screen>
The VM does not have any data from your host system, so your existing
user accounts and home directories will not be available unless you
have set <literal>mutableUsers = false</literal>. Another way is to
temporarily add the following to your configuration:
The VM does not have any data from your host system, so your existing user
accounts and home directories will not be available unless you have set
<literal>mutableUsers = false</literal>. Another way is to temporarily add
the following to your configuration:
<screen>
<link linkend="opt-users.users._name__.initialHashedPassword">users.extraUsers.your-user.initialHashedPassword</link> = "test";
</screen>
<emphasis>Important:</emphasis> delete the $hostname.qcow2 file if you
have started the virtual machine at least once without the right
users, otherwise the changes will not get picked up.
You can forward ports on the host to the guest. For
instance, the following will forward host port 2222 to guest port 22
(SSH):
<emphasis>Important:</emphasis> delete the $hostname.qcow2 file if you have
started the virtual machine at least once without the right users, otherwise
the changes will not get picked up. You can forward ports on the host to the
guest. For instance, the following will forward host port 2222 to guest port
22 (SSH):
<screen>
$ QEMU_NET_OPTS="hostfwd=tcp::2222-:22" ./result/bin/run-*-vm
</screen>
allowing you to log in via SSH (assuming you have set the appropriate
passwords or SSH authorized keys):
allowing you to log in via SSH (assuming you have set the appropriate
passwords or SSH authorized keys):
<screen>
$ ssh -p 2222 localhost
</screen>
</para>
</para>
</chapter>

26
nixos/doc/manual/installation/installation.xml
View File

@ -3,19 +3,15 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="ch-installation">
<title>Installation</title>
<partintro>
<para>This section describes how to obtain, install, and configure
NixOS for first-time use.</para>
</partintro>
<xi:include href="obtaining.xml" />
<xi:include href="installing.xml" />
<xi:include href="changing-config.xml" />
<xi:include href="upgrading.xml" />
<title>Installation</title>
<partintro>
<para>
This section describes how to obtain, install, and configure NixOS for
first-time use.
</para>
</partintro>
<xi:include href="obtaining.xml" />
<xi:include href="installing.xml" />
<xi:include href="changing-config.xml" />
<xi:include href="upgrading.xml" />
</part>

577
nixos/doc/manual/installation/installing-from-other-distro.xml
View File

@ -5,284 +5,325 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-installing-from-other-distro">
<title>Installing from another Linux distribution</title>
<title>Installing from another Linux distribution</title>
<para>
Because Nix (the package manager) &amp; Nixpkgs (the Nix packages collection)
can both be installed on any (most?) Linux distributions, they can be used to
install NixOS in various creative ways. You can, for instance:
</para>
<para>
Because Nix (the package manager) &amp; Nixpkgs (the Nix packages
collection) can both be installed on any (most?) Linux distributions,
they can be used to install NixOS in various creative ways. You can,
for instance:
</para>
<orderedlist>
<listitem>
<para>
Install NixOS on another partition, from your existing Linux distribution
(without the use of a USB or optical device!)
</para>
</listitem>
<listitem>
<para>
Install NixOS on the same partition (in place!), from your existing
non-NixOS Linux distribution using <literal>NIXOS_LUSTRATE</literal>.
</para>
</listitem>
<listitem>
<para>
Install NixOS on your hard drive from the Live CD of any Linux
distribution.
</para>
</listitem>
</orderedlist>
<orderedlist>
<listitem><para>Install NixOS on another partition, from your existing
Linux distribution (without the use of a USB or optical
device!)</para></listitem>
<para>
The first steps to all these are the same:
</para>
<listitem><para>Install NixOS on the same partition (in place!), from
your existing non-NixOS Linux distribution using
<literal>NIXOS_LUSTRATE</literal>.</para></listitem>
<listitem><para>Install NixOS on your hard drive from the Live CD of
any Linux distribution.</para></listitem>
</orderedlist>
<para>The first steps to all these are the same:</para>
<orderedlist>
<listitem>
<para>Install the Nix package manager:</para>
<para>Short version:</para>
<screen>
<orderedlist>
<listitem>
<para>
Install the Nix package manager:
</para>
<para>
Short version:
</para>
<screen>
$ bash &lt;(curl https://nixos.org/nix/install)
$ . $HOME/.nix-profile/etc/profile.d/nix.sh # …or open a fresh shell</screen>
<para>More details in the <link
<para>
More details in the
<link
xlink:href="https://nixos.org/nix/manual/#chap-quick-start">
Nix manual</link></para>
</listitem>
<listitem>
<para>Switch to the NixOS channel:</para>
<para>If you've just installed Nix on a non-NixOS distribution, you
will be on the <literal>nixpkgs</literal> channel by
default.</para>
<screen>
Nix manual</link>
</para>
</listitem>
<listitem>
<para>
Switch to the NixOS channel:
</para>
<para>
If you've just installed Nix on a non-NixOS distribution, you will be on
the <literal>nixpkgs</literal> channel by default.
</para>
<screen>
$ nix-channel --list
nixpkgs https://nixos.org/channels/nixpkgs-unstable</screen>
<para>As that channel gets released without running the NixOS
tests, it will be safer to use the <literal>nixos-*</literal>
channels instead:</para>
<screen>
<para>
As that channel gets released without running the NixOS tests, it will be
safer to use the <literal>nixos-*</literal> channels instead:
</para>
<screen>
$ nix-channel --add https://nixos.org/channels/nixos-<replaceable>version</replaceable> nixpkgs</screen>
<para>You may want to throw in a <literal>nix-channel
--update</literal> for good measure.</para>
</listitem>
<listitem>
<para>Install the NixOS installation tools:</para>
<para>You'll need <literal>nixos-generate-config</literal> and
<literal>nixos-install</literal> and we'll throw in some man
pages and <literal>nixos-enter</literal> just in case you want
to chroot into your NixOS partition. They are installed by
default on NixOS, but you don't have NixOS yet..</para>
<screen>$ nix-env -iE "_: with import &lt;nixpkgs/nixos&gt; { configuration = {}; }; with config.system.build; [ nixos-generate-config nixos-install nixos-enter manual.manpages ]"</screen>
</listitem>
<listitem>
<note><para>The following 5 steps are only for installing NixOS to
another partition. For installing NixOS in place using
<literal>NIXOS_LUSTRATE</literal>, skip ahead.</para></note>
<para>Prepare your target partition:</para>
<para>At this point it is time to prepare your target partition.
Please refer to the partitioning, file-system creation, and
mounting steps of <xref linkend="sec-installation" /></para>
<para>If you're about to install NixOS in place using
<literal>NIXOS_LUSTRATE</literal> there is nothing to do for
this step.</para>
</listitem>
<listitem>
<para>Generate your NixOS configuration:</para>
<screen>$ sudo `which nixos-generate-config` --root /mnt</screen>
<para>You'll probably want to edit the configuration files. Refer
to the <literal>nixos-generate-config</literal> step in <xref
linkend="sec-installation" /> for more information.</para>
<para>Consider setting up the NixOS bootloader to give you the
ability to boot on your existing Linux partition. For instance,
if you're using GRUB and your existing distribution is running
Ubuntu, you may want to add something like this to your
<literal>configuration.nix</literal>:</para>
<programlisting>
<para>
You may want to throw in a <literal>nix-channel --update</literal> for good
measure.
</para>
</listitem>
<listitem>
<para>
Install the NixOS installation tools:
</para>
<para>
You'll need <literal>nixos-generate-config</literal> and
<literal>nixos-install</literal> and we'll throw in some man pages and
<literal>nixos-enter</literal> just in case you want to chroot into your
NixOS partition. They are installed by default on NixOS, but you don't have
NixOS yet..
</para>
<screen>$ nix-env -iE "_: with import &lt;nixpkgs/nixos&gt; { configuration = {}; }; with config.system.build; [ nixos-generate-config nixos-install nixos-enter manual.manpages ]"</screen>
</listitem>
<listitem>
<note>
<para>
The following 5 steps are only for installing NixOS to another partition.
For installing NixOS in place using <literal>NIXOS_LUSTRATE</literal>,
skip ahead.
</para>
</note>
<para>
Prepare your target partition:
</para>
<para>
At this point it is time to prepare your target partition. Please refer to
the partitioning, file-system creation, and mounting steps of
<xref linkend="sec-installation" />
</para>
<para>
If you're about to install NixOS in place using
<literal>NIXOS_LUSTRATE</literal> there is nothing to do for this step.
</para>
</listitem>
<listitem>
<para>
Generate your NixOS configuration:
</para>
<screen>$ sudo `which nixos-generate-config` --root /mnt</screen>
<para>
You'll probably want to edit the configuration files. Refer to the
<literal>nixos-generate-config</literal> step in
<xref
linkend="sec-installation" /> for more
information.
</para>
<para>
Consider setting up the NixOS bootloader to give you the ability to boot on
your existing Linux partition. For instance, if you're using GRUB and your
existing distribution is running Ubuntu, you may want to add something like
this to your <literal>configuration.nix</literal>:
</para>
<programlisting>
<xref linkend="opt-boot.loader.grub.extraEntries"/> = ''
menuentry "Ubuntu" {
search --set=ubuntu --fs-uuid 3cc3e652-0c1f-4800-8451-033754f68e6e
configfile "($ubuntu)/boot/grub/grub.cfg"
}
'';</programlisting>
<para>(You can find the appropriate UUID for your partition in
<literal>/dev/disk/by-uuid</literal>)</para>
</listitem>
<listitem>
<para>Create the <literal>nixbld</literal> group and user on your
original distribution:</para>
<screen>
<para>
(You can find the appropriate UUID for your partition in
<literal>/dev/disk/by-uuid</literal>)
</para>
</listitem>
<listitem>
<para>
Create the <literal>nixbld</literal> group and user on your original
distribution:
</para>
<screen>
$ sudo groupadd -g 30000 nixbld
$ sudo useradd -u 30000 -g nixbld -G nixbld nixbld</screen>
</listitem>
<listitem>
<para>Download/build/install NixOS:</para>
<warning><para>Once you complete this step, you might no longer be
able to boot on existing systems without the help of a
rescue USB drive or similar.</para></warning>
<screen>$ sudo PATH="$PATH" NIX_PATH="$NIX_PATH" `which nixos-install` --root /mnt</screen>
<para>Again, please refer to the <literal>nixos-install</literal>
step in <xref linkend="sec-installation" /> for more
information.</para>
<para>That should be it for installation to another partition!</para>
</listitem>
<listitem>
<para>Optionally, you may want to clean up your non-NixOS distribution:</para>
<screen>
</listitem>
<listitem>
<para>
Download/build/install NixOS:
</para>
<warning>
<para>
Once you complete this step, you might no longer be able to boot on
existing systems without the help of a rescue USB drive or similar.
</para>
</warning>
<screen>$ sudo PATH="$PATH" NIX_PATH="$NIX_PATH" `which nixos-install` --root /mnt</screen>
<para>
Again, please refer to the <literal>nixos-install</literal> step in
<xref linkend="sec-installation" /> for more information.
</para>
<para>
That should be it for installation to another partition!
</para>
</listitem>
<listitem>
<para>
Optionally, you may want to clean up your non-NixOS distribution:
</para>
<screen>
$ sudo userdel nixbld
$ sudo groupdel nixbld</screen>
<para>If you do not wish to keep the Nix package mananager
installed either, run something like <literal>sudo rm -rv
~/.nix-* /nix</literal> and remove the line that the Nix
installer added to your <literal>~/.profile</literal>.</para>
</listitem>
<listitem>
<note><para>The following steps are only for installing NixOS in
place using
<literal>NIXOS_LUSTRATE</literal>:</para></note>
<para>Generate your NixOS configuration:</para>
<screen>$ sudo `which nixos-generate-config` --root /</screen>
<para>Note that this will place the generated configuration files
in <literal>/etc/nixos</literal>. You'll probably want to edit
the configuration files. Refer to the
<literal>nixos-generate-config</literal> step in <xref
linkend="sec-installation" /> for more information.</para>
<para>You'll likely want to set a root password for your first boot
using the configuration files because you won't have a chance
to enter a password until after you reboot. You can initalize
the root password to an empty one with this line: (and of course
don't forget to set one once you've rebooted or to lock the
account with <literal>sudo passwd -l root</literal> if you use
<literal>sudo</literal>)</para>
<programlisting>
<para>
If you do not wish to keep the Nix package manager installed either, run
something like <literal>sudo rm -rv ~/.nix-* /nix</literal> and remove the
line that the Nix installer added to your <literal>~/.profile</literal>.
</para>
</listitem>
<listitem>
<note>
<para>
The following steps are only for installing NixOS in place using
<literal>NIXOS_LUSTRATE</literal>:
</para>
</note>
<para>
Generate your NixOS configuration:
</para>
<screen>$ sudo `which nixos-generate-config` --root /</screen>
<para>
Note that this will place the generated configuration files in
<literal>/etc/nixos</literal>. You'll probably want to edit the
configuration files. Refer to the <literal>nixos-generate-config</literal>
step in <xref
linkend="sec-installation" /> for more
information.
</para>
<para>
You'll likely want to set a root password for your first boot using the
configuration files because you won't have a chance to enter a password
until after you reboot. You can initalize the root password to an empty one
with this line: (and of course don't forget to set one once you've rebooted
or to lock the account with <literal>sudo passwd -l root</literal> if you
use <literal>sudo</literal>)
</para>
<programlisting>
<link linkend="opt-users.users._name__.initialHashedPassword">users.extraUsers.root.initialHashedPassword</link> = "";
</programlisting>
</listitem>
<listitem>
<para>Build the NixOS closure and install it in the
<literal>system</literal> profile:</para>
<screen>$ nix-env -p /nix/var/nix/profiles/system -f '&lt;nixpkgs/nixos&gt;' -I nixos-config=/etc/nixos/configuration.nix -iA system</screen>
</listitem>
<listitem>
<para>Change ownership of the <literal>/nix</literal> tree to root
(since your Nix install was probably single user):</para>
<screen>$ sudo chown -R 0.0 /nix</screen>
</listitem>
<listitem>
<para>Set up the <literal>/etc/NIXOS</literal> and
<literal>/etc/NIXOS_LUSTRATE</literal> files:</para>
<para><literal>/etc/NIXOS</literal> officializes that this is now a
NixOS partition (the bootup scripts require its presence).</para>
<para><literal>/etc/NIXOS_LUSTRATE</literal> tells the NixOS bootup
scripts to move <emphasis>everything</emphasis> that's in the
root partition to <literal>/old-root</literal>. This will move
your existing distribution out of the way in the very early
stages of the NixOS bootup. There are exceptions (we do need to
keep NixOS there after all), so the NixOS lustrate process will
not touch:</para>
<itemizedlist>
<listitem><para>The <literal>/nix</literal>
directory</para></listitem>
<listitem><para>The <literal>/boot</literal>
directory</para></listitem>
<listitem><para>Any file or directory listed in
<literal>/etc/NIXOS_LUSTRATE</literal> (one per
line)</para></listitem>
</itemizedlist>
<note><para>Support for <literal>NIXOS_LUSTRATE</literal> was added
in NixOS 16.09. The act of "lustrating" refers to the
wiping of the existing distribution. Creating
<literal>/etc/NIXOS_LUSTRATE</literal> can also be used on
NixOS to remove all mutable files from your root partition
(anything that's not in <literal>/nix</literal> or
<literal>/boot</literal> gets "lustrated" on the next
boot.</para>
<para>lustrate /ˈlʌstreɪt/ verb.</para>
<para>purify by expiatory sacrifice, ceremonial washing, or
some other ritual action.</para></note>
<para>Let's create the files:</para>
<screen>
</listitem>
<listitem>
<para>
Build the NixOS closure and install it in the <literal>system</literal>
profile:
</para>
<screen>$ nix-env -p /nix/var/nix/profiles/system -f '&lt;nixpkgs/nixos&gt;' -I nixos-config=/etc/nixos/configuration.nix -iA system</screen>
</listitem>
<listitem>
<para>
Change ownership of the <literal>/nix</literal> tree to root (since your
Nix install was probably single user):
</para>
<screen>$ sudo chown -R 0.0 /nix</screen>
</listitem>
<listitem>
<para>
Set up the <literal>/etc/NIXOS</literal> and
<literal>/etc/NIXOS_LUSTRATE</literal> files:
</para>
<para>
<literal>/etc/NIXOS</literal> officializes that this is now a NixOS
partition (the bootup scripts require its presence).
</para>
<para>
<literal>/etc/NIXOS_LUSTRATE</literal> tells the NixOS bootup scripts to
move <emphasis>everything</emphasis> that's in the root partition to
<literal>/old-root</literal>. This will move your existing distribution out
of the way in the very early stages of the NixOS bootup. There are
exceptions (we do need to keep NixOS there after all), so the NixOS
lustrate process will not touch:
</para>
<itemizedlist>
<listitem>
<para>
The <literal>/nix</literal> directory
</para>
</listitem>
<listitem>
<para>
The <literal>/boot</literal> directory
</para>
</listitem>
<listitem>
<para>
Any file or directory listed in <literal>/etc/NIXOS_LUSTRATE</literal>
(one per line)
</para>
</listitem>
</itemizedlist>
<note>
<para>
Support for <literal>NIXOS_LUSTRATE</literal> was added in NixOS 16.09.
The act of "lustrating" refers to the wiping of the existing distribution.
Creating <literal>/etc/NIXOS_LUSTRATE</literal> can also be used on NixOS
to remove all mutable files from your root partition (anything that's not
in <literal>/nix</literal> or <literal>/boot</literal> gets "lustrated" on
the next boot.
</para>
<para>
lustrate /ˈlʌstreɪt/ verb.
</para>
<para>
purify by expiatory sacrifice, ceremonial washing, or some other ritual
action.
</para>
</note>
<para>
Let's create the files:
</para>
<screen>
$ sudo touch /etc/NIXOS
$ sudo touch /etc/NIXOS_LUSTRATE
</screen>
<para>Let's also make sure the NixOS configuration files are kept
once we reboot on NixOS:</para>
<screen>
<para>
Let's also make sure the NixOS configuration files are kept once we reboot
on NixOS:
</para>
<screen>
$ echo etc/nixos | sudo tee -a /etc/NIXOS_LUSTRATE
</screen>
</listitem>
<listitem>
<para>Finally, move the <literal>/boot</literal> directory of your
current distribution out of the way (the lustrate process will
take care of the rest once you reboot, but this one must be
moved out now because NixOS needs to install its own boot
files:</para>
<warning><para>Once you complete this step, your current
distribution will no longer be bootable! If you didn't get
all the NixOS configuration right, especially those
settings pertaining to boot loading and root partition,
NixOS may not be bootable either. Have a USB rescue device
ready in case this happens. </para></warning>
<screen>
</listitem>
<listitem>
<para>
Finally, move the <literal>/boot</literal> directory of your current
distribution out of the way (the lustrate process will take care of the
rest once you reboot, but this one must be moved out now because NixOS
needs to install its own boot files:
</para>
<warning>
<para>
Once you complete this step, your current distribution will no longer be
bootable! If you didn't get all the NixOS configuration right, especially
those settings pertaining to boot loading and root partition, NixOS may
not be bootable either. Have a USB rescue device ready in case this
happens.
</para>
</warning>
<screen>
$ sudo mv -v /boot /boot.bak &amp;&amp;
sudo /nix/var/nix/profiles/system/bin/switch-to-configuration boot</screen>
<para>Cross your fingers, reboot, hopefully you should get a NixOS
prompt!</para>
</listitem>
<listitem>
<para>If for some reason you want to revert to the old
distribution, you'll need to boot on a USB rescue disk and do
something along these lines:</para>
<screen>
<para>
Cross your fingers, reboot, hopefully you should get a NixOS prompt!
</para>
</listitem>
<listitem>
<para>
If for some reason you want to revert to the old distribution, you'll need
to boot on a USB rescue disk and do something along these lines:
</para>
<screen>
# mkdir root
# mount /dev/sdaX root
# mkdir root/nixos-root
@ -291,23 +332,25 @@ $ sudo mv -v /boot /boot.bak &amp;&amp;
# mv -v root/boot.bak root/boot # We had renamed this by hand earlier
# umount root
# reboot</screen>
<para>This may work as is or you might also need to reinstall the
boot loader</para>
<para>And of course, if you're happy with NixOS and no longer need
the old distribution:</para>
<screen>sudo rm -rf /old-root</screen>
</listitem>
<listitem>
<para>It's also worth noting that this whole process can be
automated. This is especially useful for Cloud VMs, where
provider do not provide NixOS. For instance, <link
<para>
This may work as is or you might also need to reinstall the boot loader
</para>
<para>
And of course, if you're happy with NixOS and no longer need the old
distribution:
</para>
<screen>sudo rm -rf /old-root</screen>
</listitem>
<listitem>
<para>
It's also worth noting that this whole process can be automated. This is
especially useful for Cloud VMs, where provider do not provide NixOS. For
instance,
<link
xlink:href="https://github.com/elitak/nixos-infect">nixos-infect</link>
uses the lustrate process to convert Digital Ocean droplets to
NixOS from other distributions automatically.</para>
</listitem>
</orderedlist>
uses the lustrate process to convert Digital Ocean droplets to NixOS from
other distributions automatically.
</para>
</listitem>
</orderedlist>
</section>

74
nixos/doc/manual/installation/installing-pxe.xml
View File

@ -3,46 +3,48 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-booting-from-pxe">
<title>Booting from the <quote>netboot</quote> media (PXE)</title>
<title>Booting from the <quote>netboot</quote> media (PXE)</title>
<para>
Advanced users may wish to install NixOS using an existing PXE or
iPXE setup.
</para>
<para>
<para>
Advanced users may wish to install NixOS using an existing PXE or iPXE setup.
</para>
<para>
These instructions assume that you have an existing PXE or iPXE
infrastructure and simply want to add the NixOS installer as another
option. To build the necessary files from a recent version of
nixpkgs, you can run:
</para>
infrastructure and simply want to add the NixOS installer as another option.
To build the necessary files from a recent version of nixpkgs, you can run:
</para>
<programlisting>
nix-build -A netboot nixos/release.nix
</programlisting>
<para>
This will create a <literal>result</literal> directory containing: *
<literal>bzImage</literal> – the Linux kernel *
<literal>initrd</literal> – the initrd file *
<literal>netboot.ipxe</literal> – an example ipxe script
demonstrating the appropriate kernel command line arguments for this
image
</para>
<para>
If you’re using plain PXE, configure your boot loader to use the
<literal>bzImage</literal> and <literal>initrd</literal> files and
have it provide the same kernel command line arguments found in
<literal>netboot.ipxe</literal>.
</para>
<para>
If you’re using iPXE, depending on how your HTTP/FTP/etc. server is
configured you may be able to use <literal>netboot.ipxe</literal>
unmodified, or you may need to update the paths to the files to
match your server’s directory layout
</para>
<para>
In the future we may begin making these files available as build
products from hydra at which point we will update this documentation
with instructions on how to obtain them either for placing on a
dedicated TFTP server or to boot them directly over the internet.
</para>
<para>
This will create a <literal>result</literal> directory containing: *
<literal>bzImage</literal> – the Linux kernel * <literal>initrd</literal>
– the initrd file * <literal>netboot.ipxe</literal> – an example ipxe
script demonstrating the appropriate kernel command line arguments for this
image
</para>
<para>
If you’re using plain PXE, configure your boot loader to use the
<literal>bzImage</literal> and <literal>initrd</literal> files and have it
provide the same kernel command line arguments found in
<literal>netboot.ipxe</literal>.
</para>
<para>
If you’re using iPXE, depending on how your HTTP/FTP/etc. server is
configured you may be able to use <literal>netboot.ipxe</literal> unmodified,
or you may need to update the paths to the files to match your server’s
directory layout
</para>
<para>
In the future we may begin making these files available as build products
from hydra at which point we will update this documentation with instructions
on how to obtain them either for placing on a dedicated TFTP server or to
boot them directly over the internet.
</para>
</section>

89
nixos/doc/manual/installation/installing-usb.xml
View File

@ -3,17 +3,19 @@
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-booting-from-usb">
<title>Booting from a USB Drive</title>
<title>Booting from a USB Drive</title>
<para>
For systems without CD drive, the NixOS live CD can be booted from a USB
stick. You can use the <command>dd</command> utility to write the image:
<command>dd if=<replaceable>path-to-image</replaceable>
of=<replaceable>/dev/sdb</replaceable></command>. Be careful about specifying
the correct drive; you can use the <command>lsblk</command> command to get a
list of block devices.
</para>
<para>For systems without CD drive, the NixOS live CD can be booted from
a USB stick. You can use the <command>dd</command> utility to write the image:
<command>dd if=<replaceable>path-to-image</replaceable>
of=<replaceable>/dev/sdb</replaceable></command>. Be careful about specifying the
correct drive; you can use the <command>lsblk</command> command to get a list of
block devices.</para>
<para>On macOS:
<para>
On macOS:
<programlisting>
$ diskutil list
[..]
@ -24,36 +26,43 @@ $ diskutil unmountDisk diskN
Unmount of all volumes on diskN was successful
$ sudo dd bs=1m if=nix.iso of=/dev/rdiskN
</programlisting>
Using the 'raw' <command>rdiskN</command> device instead of <command>diskN</command>
completes in minutes instead of hours. After <command>dd</command> completes, a GUI
dialog "The disk you inserted was not readable by this computer" will pop up, which
can be ignored.</para>
<para>The <command>dd</command> utility will write the image verbatim to the drive,
making it the recommended option for both UEFI and non-UEFI installations. For
non-UEFI installations, you can alternatively use
<link xlink:href="http://unetbootin.sourceforge.net/">unetbootin</link>. If you
cannot use <command>dd</command> for a UEFI installation, you can also mount the
ISO, copy its contents verbatim to your drive, then either:
<itemizedlist>
<listitem>
<para>Change the label of the disk partition to the label of the ISO
(visible with the blkid command), or</para>
</listitem>
<listitem>
<para>Edit <filename>loader/entries/nixos-livecd.conf</filename> on the drive
and change the <literal>root=</literal> field in the <literal>options</literal>
line to point to your drive (see the documentation on <literal>root=</literal>
in <link xlink:href="https://www.kernel.org/doc/Documentation/admin-guide/kernel-parameters.txt">
the kernel documentation</link> for more details).</para>
</listitem>
<listitem>
<para>If you want to load the contents of the ISO to ram after bootin
(So you can remove the stick after bootup) you can append the parameter
<literal>copytoram</literal> to the <literal>options</literal> field.</para>
</listitem>
</itemizedlist>
</para>
Using the 'raw' <command>rdiskN</command> device instead of
<command>diskN</command> completes in minutes instead of hours. After
<command>dd</command> completes, a GUI dialog "The disk you inserted was not
readable by this computer" will pop up, which can be ignored.
</para>
<para>
The <command>dd</command> utility will write the image verbatim to the drive,
making it the recommended option for both UEFI and non-UEFI installations.
For non-UEFI installations, you can alternatively use
<link xlink:href="http://unetbootin.sourceforge.net/">unetbootin</link>. If
you cannot use <command>dd</command> for a UEFI installation, you can also
mount the ISO, copy its contents verbatim to your drive, then either:
<itemizedlist>
<listitem>
<para>
Change the label of the disk partition to the label of the ISO (visible
with the blkid command), or
</para>
</listitem>
<listitem>
<para>
Edit <filename>loader/entries/nixos-livecd.conf</filename> on the drive
and change the <literal>root=</literal> field in the
<literal>options</literal> line to point to your drive (see the
documentation on <literal>root=</literal> in
<link xlink:href="https://www.kernel.org/doc/Documentation/admin-guide/kernel-parameters.txt">
the kernel documentation</link> for more details).
</para>
</listitem>
<listitem>
<para>
If you want to load the contents of the ISO to ram after bootin (So you
can remove the stick after bootup) you can append the parameter
<literal>copytoram</literal> to the <literal>options</literal> field.
</para>
</listitem>
</itemizedlist>
</para>
</section>

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