We should sometimes restart the units rather than reloading them so the
changes are actually applied. / and /nix are explicitly excluded because
there was some very old issue where these were unmounted. I don't think
this will affect many people since most people use fstab mounts instead
but I plan to adapt this behavior for fstab mounts as well in the future
(once I wrote a test for the fstab thingies).
Call dbus by using `$cur_systemd/busctl --json=...` and core modules
JSON::PP and IPC::Cmd to slim down dependencies for baseSystem.
perlPackages.NetDBus pulls in quite a few other dependencies, like
XML::Twig, LWP, and HTTP::Daemon. These are not really neccecary for
s-t-c, and some of them have caused issues particularly with cross
builds after updates to perlPackages.
Use a quoted heredoc to inject installBootLoader safely into the script,
and restore the previous invocation of `system` with a single argument so
that shell commands keep working.
This bug is so obscure and unlikely that I was honestly not able to
properly write a test for it. What happens is that we are calling
handleModifiedUnit() with $unitsToStart=\%unitsToRestart. We do this to
make sure that the unit is stopped before it's started again which is
not possible by regular means because the stop phase is already done
when calling the activation script.
recordUnit() still gets $startListFile, however which is the wrong file.
The bug would be triggered if an activation script requests a service
restart for a service that has `stopIfChanged = true` and
switch-to-configuration is killed before the restart phase was run. If
the script is run again, but the activation script is not requesting
more restarts, the unit would be started instead of restarted.
systemd needs this so special characters (like the ones in wireguard
units that appear because they are part of base64) can be escaped using
the \x syntax.
Root of the issue is that `glob()` handles the backslash internally
which is obviously not what we want here.
Also add a test case and fix some perlcritic issues in the subroutine.
This is accomplished by comparing the hashes that the unit files
contain. By filtering for a special key `X-Reload-Triggers` in the
`[Unit]` section, we can differentiate between reloads and restarts.
Since activation scripts can request reloads of units as well, more
checking of this behaviour is implemented. If a unit is to be restarted,
it's never reloaded as well which would make no sense.
Also removes a useless subroutine and perl dependencies that are
nowadays handled by the propagated build inputs feature of
`perl.withPackages`.
- Fully get rid of `parseKeyValues` and use systemctl features for that
- Add some regex modifiers recommended by perlcritic
- Get rid of a postfix if
- Sort units when showing their status
- Clean the logic for showing what failed from `elif` to `next`
- Switch from `state` to `substate` for `auto-restart` because that's
actually where the value is stored
- Show status of units with one single systemctl call and get rid of
COLUMNS in favor of --full
- Add a test for failing units
This replaces the naive K=V unit parser with a proper INI parser from a
library and adds proper support for override files. Also adds a bunch of
comments about parsing, I hope this makes it easier to understand and
maintain in the future.
There are multiple reasons to do so, the first one is just general
correctness with is nice imo. But to get to more serious reasons (I
didn't put in all that effort for nothing) is that this is the first
step torwards more clever restart/reload handling. By using a library
like Data::Compare a future PR could replace the current way of
fingerprinting units (which is to compare store paths) by comparing the
hashes. This is more precise because units won't get restarted because
the order of the options change, comments are added, some dependency of
writeText changes, .... Also this allows us to add a feature like
`X-Reload-Triggers` so the unit can either be reloaded when these change
or restarted when everything else changes, giving module authors the
ability to have their services reloaded without having to fear that
updates are not applied because the service doesn't get restarted.
Another reason why this feature is nice is that now that the unit files
are parsed correctly (and values are just extracted from one section),
potential future rewrites can just rely on some INI library without
having to implement their own weird parser that is compatible with this
script.
This also comes with a new subroutine to handle systemd booleans because
I thought the current way of handling it was just ugly. This also allows
overriding values this script reads in an override file.
Apart from making this script more compatible with the world around it,
this also fixes two issues I saw bugging exactly 0 (zero) people. First
is that this script now supports multiple override files, also ones that
are not called override.conf and the second one is that `1` and `on` are
treated as bools by systemd but were previously not parsed as such by
switch-to-configuration.
This removes `/run/nixos/activation-reload-list` (which we will need in
the future when reworking the reload logic) and makes
`/run/nixos/activation-restart-list` honor `restartIfChanged` and
`reloadIfChanged`. This way activation scripts don't have to bother with
choosing between reloading and restarting.
The first one doesn't make any sense because the directory where the
init binary resides does not contain other tools we need like
systemd-escape.
The second one doesn't make sense either because the errors are already
ignored.
This reverts commit 57961d2b83, reversing
changes made to b04f913afc.
(I.e. this reverts PR #141192.)
While well-intended, this change does unfortunately introduce very
serious regressions that are especially disruptive/noticeable on desktop
systems (e.g. users of Sway will loose their graphical session when
running "nixos-rebuild switch").
Therefore, this change has to be reverted ASAP instead of trying to fix
it in "production".
Note: An updated version should be extensively discussed, reviewed, and
tested before re-landing this change as an earlier version also had to
be reverted for the exact same issues [0].
Fix: #146727
[0]: https://github.com/NixOS/nixpkgs/pull/73871#issuecomment-559783752
