It's a dull and boring day, it's cold outside and I'm stuck at home: let
me tell you the story of systemd-vconsole-setup.
In the beginnings of NixOS[1], systemd-vconsole-setup was a powerful
sysinit.target unit, installed and running at boot to set up fonts
keyboard layouts and even colors of the virtual consoles. If needed, the
service would also be restarted after a configuration change, consoles
were happy and everything was good, well, almost.
Since the service had no way to specify the dependency "ttys are ready",
modesetting could sometimes happen *after* systemd-vconsole-setup had
started, leaving the console in a broken state. So abbradar worked
around that by putting a systemd-udev-settle `After=`.
In the meanwhile, probably realizing their mistake, systemd added a
shiny udev rule to start the systemd-udev-settle at the right time[2].
However, the rule bypassed systemd by directly running the binary
`systemd-udev-settle`, and the service - though still installed - fell
into disuse.
Two years would pass before a good samaritan, seeing the poor jobless
systemd-udev-settle service, decided to give it the coup de grâs[3] by
unlisting it from the installed units.
This, combined with another bug, caused quite a commotion[4] in NixOS;
to see why remember the fact that `WantedBy=` in upstream units doesn't
work[5], so it had to be added manually in cc542110, but while systemd
removed it, the NixOS unit continued to install and restart the service,
making a lot of fuss when switching configuration.
After at least thee different tentative fixes, deedrah realised[6] what
the root cause was and fpletz put the final nail[7] in the coffin of
systemd-udev-settle. The service would never see the light of a boot
again, NixOS would not restart it all the time but thanks to udev
consoles would still get their pretty fonts and playful colors.
The En..
..no, wait! You should ask what came of systemd-udev-settle, first.
And why is the service even around if udev is doing all the work?
Udev-settle, like the deceitful snake that he is, laid hidden for years.
He looks innocuous doesn't it? A little hack. Only until it leaves his
den and a poor user[8] drops dead. Obviously, it serves no purpose, as
the service is not part of the boot process anymore, so let's remove it
for good!
About the service, it may not be useful at boot, but it can be started
to pick up changes in vconsole.conf and set the consoles accordingly.
But wait, this doesn't work anymore: the service is never started at
boot (remember f76d2aa6), so switch-to-configuration.pl will not restart
it. Fortunately it can be repaired: here I install a new unit which
does *nothing* on start, but restarts the real service when reloaded.
This perfectly reproduces the original behavior, hopefully without the
original bugs too.
The End?
[1]: cc54211069
[2]: f6ba8671d8 (diff-84849fddcef81458f69725dc18c6614aade5c4f41a032b6908ebcf1ee6740636)
[3]: 8125e8d38e
[4]: https://web.archive.org/web/20180603130107/https://github.com/NixOS/nixpkgs/issues/22470
[5]: https://github.com/NixOS/nixpkgs/issues/81138
[6]: https://web.archive.org/web/20180603130107/https://github.com/NixOS/nixpkgs/issues/22470#issuecomment-330930456
[7]: f76d2aa6e3
[8]: https://github.com/NixOS/nixpkgs/issues/107341
Say this 10 times so I don't forget:
- just because something has been tested and confirmed working, doesn't
mean that a trivial change can go in without testing simply because
it looks OK. test, test, test.
- just because something has been tested and confirmed working, doesn't
mean that a trivial change can go in without testing simply because
it looks OK. test, test, test.
- just because something has been tested and confirmed working, doesn't
mean that a trivial change can go in without testing simply because
it looks OK. test, test, test.
- just because something has been tested and confirmed working, doesn't
mean that a trivial change can go in without testing simply because
it looks OK. test, test, test.
- just because something has been tested and confirmed working, doesn't
mean that a trivial change can go in without testing simply because
it looks OK. test, test, test.
- just because something has been tested and confirmed working, doesn't
mean that a trivial change can go in without testing simply because
it looks OK. test, test, test.
- just because something has been tested and confirmed working, doesn't
mean that a trivial change can go in without testing simply because
it looks OK. test, test, test.
- just because something has been tested and confirmed working, doesn't
mean that a trivial change can go in without testing simply because
it looks OK. test, test, test.
- just because something has been tested and confirmed working, doesn't
mean that a trivial change can go in without testing simply because
it looks OK. test, test, test.
- just because something has been tested and confirmed working, doesn't
mean that a trivial change can go in without testing simply because
it looks OK. test, test, test.
I'm sorry guys.
4255954d97 set the StateDirectory to 0750,
but nginx wasn't in the Mastodon group. This commit also deletes a line,
that probably was intended to serve this purpose, but makes no sense.
Why should the Mastodon user be added as an extraGroup to the nginx
user?
Ensure that the HyperV keyboard driver is available in the early
stages of the boot process. This allows the user to enter a disk
encryption passphrase or repair a boot problem in an interactive
shell.
The `--apis=` command line parameter passed to Jitsi Videobridge is
required to monitor a Jitsi Meet instance for example via the prometheus
exporter [jitsiexporter](https://git.xsfx.dev/prometheus/jitsiexporter).
@thelegy writes:
unitOption is only used inside of attrsOf wich is perfectly capable of
handling the attrsets from mkIf, though the checkUnitConfig test
forbids it.
This commit weakens that restriction to allow the usage of mkIf inside
of systemd.services.<name>.serviceConfig.<something> etc.
While I personally don't like that we can't easily use
pushDownProperties from the module system and need to rely on internals,
we *already* use internals for the mkOverride case, so adding another
case for mkIf doesn't add a hard-to-find indirection.
I'm merging this, since this fixes a valid use case and it shouldn't
make refactoring worse than before.
The NixOS 21.03 release has been delayed to 21.05. See NixOS/rfcs#80.
There are two instances of 21.03 which have been left as is, since they
are in stateVersion comparisons. This will ensure that existing user
configurations which refer to 21.03 will continue to work.
`unitOption` is only used inside of `attrsOf` wich is perfectly capable of
handling the attrsets from `mkIf`, though the checkUnitConfig test
forbids it. This commit weakens that restriction to allow the usage of
`mkIf` inside of `systemd.services.<name>.serviceConfig.<something>`
etc.
Account for the fact that, when creating a lua package without the
"withPackages" helper, we dont get an extra "lua" attribute in the
package.
Therefore we need to distinguish between the "withPackages" case and the
direct ( or "empty" ) lua package.
For example with this nixos config:
```nix
{
services.httpd = {
enable = true;
package = pkgs.apacheHttpd.override {
luaSupport = true;
lua5 = pkgs.lua5_3.withPackages (ps: with ps; [ luafilesystem ] );
};
};
}
```
Here we say that we want to have apache to use a lua, packaged with the
`luafilesystem` module so that we can `require` that in scripts to
render http responses. There, the set that gets assigned to `lua5 ` does
not have a `luaversion` attribute, rather it has a `lua` attribute
wherein lies a `luaversion` attribute. If we dont package additional
modules, then we dont have that `lua` attribute in between and rather
directly have to use `luaversion` directly.
