Before this change, systemd-oomd startup was flaky at least with
either systemd-sysusers or userborn enabled. It would restart several
times until users were provisioned, so that it finally succeeded.
An alternative would be to use a DynamicUser which was my first
approach, before I discovered that upstream added the after statement
in Dec 2024[1]. DynamicUsers could have further
implications (sandboxing, etc), so we follow upstream here.
It's not clear to me we why Upstreams "After=systemd-sysusers.service"
doesn't show up on nixos-unstable systems (systemd v257.6).
Userborn is covered, as its unit is aliased to systemd-sysusers.service.
The following test succeeded after this change on x86_64-linux:
nix-build -A nixosTests.systemd-oomd
[1]: 36dd429680
When running with a xfs root partition and using systemd for stage 1
initrd, I noticed in journalctl that fsck.xfs always failed to execute.
The issue is that it is trying to use the below sh interpreter:
`#!/nix/store/xy4jjgw87sbgwylm5kn047d9gkbhsr9x-bash-5.2p37/bin/sh -f`
but the file does not exist in the initrd image.
/nix/store/xy4jjgw87sbgwylm5kn047d9gkbhsr9x-bash-5.2p37/bin/**bash**
exists since it gets pulled in by some package, but the rest of the
directory is not being pulled in.
boot/systemd/initrd.nix mentions that xfs_progs references the sh
interpreter and seems to explicitly try to address this by adding
${pkgs.bash}/bin to storePaths, but that's the wrong bash package.
Update the `storePaths` value to pull in `pkgs.bashNonInteractive`
rather than `pkgs.bash`.
Fixes#361592.
I was able to test this change by doing the following:
1. Create a file named “test-systemd-run0.nix” that contains this Nix
expression:
let
nixpkgs = /path/to/nixpkgs;
pkgs = import nixpkgs { };
in
pkgs.testers.runNixOSTest {
name = "test-systemd-run0";
nodes.machine = {
security.polkit.enable = true;
};
testScript = ''
start_all()
machine.succeed("run0 env")
'';
}
2. Replace “/path/to/nixpkgs” with the actual path to an actual copy of
Nixpkgs.
3. Run the integration test by running this command:
nix-build <path to test-systemd-run0.nix>
`user-.slice` does not seem to exist, and the config we generate for it is
rejected by systemd (see `systemctl status user-.slice`).
I suppose that what was really intended here, was to configure
`user.slice`, which is the one that is documented in `man systemd.special`.
Reported-by: Ian Sollars <Ian.Sollars@brussels.msf.org>
We should not remount all filesystem types since not all filesystems
are safe to remount and some (nfs) return errors if remounted with
certain mount options.
The enable attribute of `boot.initrd.systemd.contents.<name>` was
ignored for building initrd storePaths. This resulted in building
derivations for the initrd even if it was disabled.
Found while testing a to build a nixos system with a kernel without
lodable modules[0]
[0]: https://github.com/NixOS/nixpkgs/pull/411792
We currently bypass systemd's switch-root logic by premounting
/sysroot/run. Make sure to propagate its sub-mounts with the recursive
flag, in accordance with the default switch-root logic.
This is required for creds at /run/credentials to survive the transition
from initrd -> host.
I was confused why I could not get an emergency access console despite setting systemd.emergencyMode=true.
Turns out there is another similar option `boot.initrd.systemd.emergencyAccess` that I should have used.
This is confusing and this change should make it more clear vie the docs of both these options.
