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`.
The `nix.*` options, apart from options for setting up the
daemon itself, currently provide a lot of setting mappings
for the Nix daemon configuration. The scope of the mapping yields
convience, but the line where an option is considered essential
is blurry. For instance, the `extra-sandbox-paths` mapping is
provided without its primary consumer, and the corresponding
`sandbox-paths` option is also not mapped.
The current system increases the maintenance burden as maintainers have to
closely follow upstream changes. In this case, there are two state versions
of Nix which have to be maintained collectively, with different options
avaliable.
This commit aims to following the standard outlined in RFC 42[1] to
implement a structural setting pattern. The Nix configuration is encoded
at its core as key-value pairs which maps nicely to attribute sets, making
it feasible to express in the Nix language itself. Some existing options are
kept such as `buildMachines` and `registry` which present a simplified interface
to managing the respective settings. The interface is exposed as `nix.settings`.
Legacy configurations are mapped to their corresponding options under `nix.settings`
for backwards compatibility.
Various options settings in other nixos modules and relevant tests have been
updated to use structural setting for consistency.
The generation and validation of the configration file has been modified to
use `writeTextFile` instead of `runCommand` for clarity. Note that validation
is now mandatory as strict checking of options has been pushed down to the
derivation level due to freeformType consuming unmatched options. Furthermore,
validation can not occur when cross-compiling due to current limitations.
A new option `publicHostKey` was added to the `buildMachines`
submodule corresponding to the base64 encoded public host key settings
exposed in the builder syntax. The build machine generation was subsequently
rewritten to use `concatStringsSep` for better performance by grouping
concatenations.
[1] - https://github.com/NixOS/rfcs/blob/master/rfcs/0042-config-option.md
This option behaves exactly like `boot.extraModprobeConfig`, except that it also includes the generated modprobe.d file in the initrd.
Many years ago, someone tried to include the normal modprobe.d/nixos.conf file generated by `boot.extraModprobeConfig` in the initrd: 0aa2c1dc46. This file contains a reference to a directory with firmware files inside. Including firmware in the initrd made it too big, so the commit was reverted again in 4a4c051a95.
The `boot.extraModprobeConfig` option not changing the initrd caused me much confusion because I tried to set the maximum cache size for ZFS and it didn't work.
Closes https://github.com/NixOS/nixpkgs/issues/25456.
Modules that do not depend on e.g. toplevel should not have to include it just to set
things in `system.build`. As a general rule, this keeps tests simple, usage flexible
and evaluation fast. While one module is insignificant, consistency and good practices
are.
If the Nix daemon has never been enabled (nix.enable has always been
set to false), the gcroots directory won't exist. If the Nix daemon
is later enabled, the GC roots for booted-system and current-system
will be missing, and they might end up being garbage collected. Since
it's cheap to add GC roots even if the daemon will never be enabled,
let's just always add them so we're okay in the case where the daemon
is enabled later.
- 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.
I was confused why I couldn't find a mention of udev.log_priority in
systemd-udevd.service(8). It turns out that it was renamed[1] to
udev.log_level. The old name is still accepted, but it'll avoid
further confusion if we use the new name in our documentation.
[1]: 64a3494c3d
