Since 03eaa48 added perl.withPackages, there is a canonical way to
create a perl interpreter from a list of libraries, for use in script
shebangs or generic build inputs. This method is declarative (what we
are doing is clear), produces short shebangs[1] and needs not to wrap
existing scripts.
Unfortunately there are a few exceptions that I've found:
1. Scripts that are calling perl with the -T switch. This makes perl
ignore PERL5LIB, which is what perl.withPackages is using to inform
the interpreter of the library paths.
2. Perl packages that depends on libraries in their own path. This
is not possible because perl.withPackages works at build time. The
workaround is to add `-I $out/${perl.libPrefix}` to the shebang.
In all other cases I propose to switch to perl.withPackages.
[1]: https://lwn.net/Articles/779997/
This option can be set to disable installer tools like nixos-rebuild,
nixos-install, and nixos-generate-config (as well as more). This is
nice when a system is not expected to be rebuild or reconfigure itself
such as in a stateless PXE setup, as well as other embedded scenarios.
Note, that the system can still be updated, but it must either get
nixos-rebuild from another source, or, for embedded systems, be
upgraded by another machine like:
nix copy "$system" --to "ssh://root@<host>" && ssh "root@<host>"
"nix-env -p /nix/var/nix/profiles/system --set $system && $system/bin/switch-to-configuration switch".
Along with other options, this allows removing Perl from a closure.
For example:
{
boot.enableContainers = false;
environment.defaultPackages = [];
system.disableInstallerTools = true;
}
should not include Perl.
The only nix version available in the installer should be the version
configure in the module system. If someone needs `nixUnstable` in their
`nixos-install` they should probably set the module option and not just
add it to the closure.
Also add --all, which shows the value of all options. Diffing the --all
output on either side of contemplated changes is a lovely way to better
understand what's going on inside nixos.
This sets networking.useDHCP to false and for all interfaces found the
per-interface useDHCP to true. This replicates the current default
behaviour and prepares for the switch to networkd.
cross-compilation of `btrfs-tools` is broken, and this usually needless dependency of each system closure on `btrfs-tools` prevents cross-compilation of whole system closures
The use of Nix 2.0 significantly simplifies the installer, since we
can just pass a different store URI (--store /mnt) - it's no longer
needed to set up a chroot environment for the build, and to bootstrap
Nix into the chroot.
Also, commands that need to run in the installation (namely boot
loader installation and setting a root password) are now executed
using nixos-enter.
This also removes the need for nixos-prepare-root since any required
initialisation is done by Nix or by the activation script.
The key distinction I'm drawing is that there's a component that deals
with the store of the machine being built, and another component for
the store building it. The inner part of it assumes nothing from the
builder (doesn't need chroot or root powers) so it can run comfortably
inside a Nix build, as well as nixos-rebuild. I have some upcoming work
that will use that to significantly speed up and streamline image builds
for NixOS, especially on virtualized hosts like EC2, but it's also a
reasonable speedup on native hosts.
This partially reverts commit 0aa7520670.
Fine for rsync to be in system path but we still need the explicit path
in nixos-install in case it is invoked from non-NixOS systems and also
to fix OVA test failure
See also 0aa7520670
cc @edolstra
This reverts commit 582313bafe.
Removing rsync is actually pointless because nixos-install depends on
it. So if it's part of the system closure, we may as well provide it
to users.
Probably with the next Nix release we can drop the use of rsync and
use "nix copy" instead.
- Replace hand-rolled version of nixos-install in make-disk-image by an
actual call to nixos-install
- Required a few cleanups of nixos-install
- nixos-install invokes an activation script which the hand-rolled version
in make-disk-image did not do. We remove /etc/machine-id as that's
a host-specific, impure, output of the activation script
Testing:
nix-build '<nixpkgs/nixos/release.nix>' -A tests.installer.simple passes
Also tried generating an image with:
nix-build -E 'let
pkgs = import <nixpkgs> {};
lib = pkgs.lib;
nixos = import <nixpkgs/nixos> {
configuration = {
fileSystems."/".device = "/dev/disk/by-label/nixos";
boot.loader.grub.devices = [ "/dev/sda" ];
boot.loader.grub.extraEntries = '"''"'
menuentry "Ubuntu" {
insmod ext2
search --set=root --label ubuntu
configfile /boot/grub/grub.cfg
}
'"''"';
};
};
in import <nixpkgs/nixos/lib/make-disk-image.nix> {
inherit pkgs lib;
config = nixos.config;
diskSize = 2000;
partitioned = false;
installBootLoader = false;
}'
Then installed the image:
$ sudo df if=./result/nixos.img of=/dev/sdaX bs=1M
$ sudo resize2fs /dev/disk/by-label/nixos
$ sudo mount /dev/disk/by-label/nixos /mnt
$ sudo mount --rbind /proc /mnt/proc
$ sudo mount --rbind /dev /mnt/dev
$ sudo chroot /mnt /nix/var/nix/profiles/system/bin/switch-to-configuration boot
[ … optionally do something about passwords … ]
and successfully rebooted to that image.
Was doing all this from inside a Ubuntu VM with a single user nix install.
- Fix --no-bootloader which didn't do what it advertised
- Hardcode nixbld GID so that systems which do not have a nixbld user
can still run nixos-install (only with --closure since they can't
build anything)
- Cleanup: get rid of NIX_CONF_DIR(=/tmp)/nix.conf and pass arguments instead
- Cleanup: don't assume that the target system has '<nixpkgs/nixos>' or
'<nixos-config>' to see if config.users.mutableUsers. Instead check if
/var/setuid-wrappers/passwd is there
Installing NixOS now works from a Ubuntu host (using --closure).
nix-build -A tests.installer.simple '<nixpkgs/nixos/release.nix>' succeeds ✓
