using freeform is the new standard way of using modules and should replace
extraConfig.
In particular, this will allow us to place a condition on mails
This accomplishes multiple things:
- Allows us to start systemd without stage-2-init.sh. This was not
possible before because the environment would have been wrong
- `systemctl daemon-reexec` also changes the environment, giving us
newer tools for the fs packages
- Starts systemd in a fully clean environment, making everything more
consistent and pure
Currently it is only possible to add upstream _system_ units. The option
systemd.additionalUpstreamSystemUnits can be used for this.
However, this was not yet possible for systemd.user. In a similar
fashion this was added to systemd-user.nix.
This is intended to have other modules add upstream units.
wtmp and btmp are created by systemd, so the rules are more appropriate there.
They can be disabled explicitly with something like
services.ogrotate.paths = {
"/var/log/btmp".enable = false;
"/var/log/wtmp".enable = false;
};
if required.
The mount options need to be passed as a comma-separated list of options so that they
end up one a single Options line in the resulting mount unit.
The current code passed the options as a list, resulting in several Options lines in
the mount unit, all but the first of these were ignored by systemd however.
This behaviour is not clearly defined in the systemd man page.
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.
