This option is made uncondiotional in systemd 258 [1].
Earlier, it defaulted to true on kernels newer than 4.15,
which applies to all supported nixos kernels.
This means removing the option does not change behavior.
[1] 29da53dde3
This brings our `run0` in line with the upstream defaults:
bcc73cafdb/src/run/systemd-run0.in
While working on `auditd`, i noticed differences in how `run0` behaves
in regard to `/proc/$pid/sessionid` and `/proc/$pid/loginuid`. Particularly,
both files were set to `4294967295`, the magic value denoting `unset`.
While the manual page says elevators such as sudo should not set the loginuid,
run0 is a bit of a special case: The unit spawned by it is not child of
the running user session, and as such there is no id to inherit.
`systemd` upstream uses `pam_loginuid`, and for consistency we should too.
Especially because it prevents a whole lot of pain when working with `auditd`.
As to pam mounts:
On nixos we enable those if they are globally enabled. Upstream does not.
Considering the password entered into polkit is usually not the user password
of the account which will own the unit, pam mount will fail for any partition
which requires a password. Thus it makes sense to also disable pam mounts
for our run0, it prevents unnecessary unexpected pain.
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>
Format all Nix files using the officially approved formatter,
making the CI check introduced in the previous commit succeed:
nix-build ci -A fmt.check
This is the next step of the of the [implementation](https://github.com/NixOS/nixfmt/issues/153)
of the accepted [RFC 166](https://github.com/NixOS/rfcs/pull/166).
This commit will lead to merge conflicts for a number of PRs,
up to an estimated ~1100 (~33%) among the PRs with activity in the past 2
months, but that should be lower than what it would be without the previous
[partial treewide format](https://github.com/NixOS/nixpkgs/pull/322537).
Merge conflicts caused by this commit can now automatically be resolved while rebasing using the
[auto-rebase script](8616af08d9/maintainers/scripts/auto-rebase).
If you run into any problems regarding any of this, please reach out to the
[formatting team](https://nixos.org/community/teams/formatting/) by
pinging @NixOS/nix-formatting.
Some upstream systemd units are conditionally installed into the systemd
output, so we must make sure the feature that enables their installation
is enabled on our side prior to trying to use them.
tracefs is a special-purpose filesystem in Linux used for tracing filesystem and kernel operations.
This was added to the kernel back in 2015 to replace debugfs. For security reasons, some system do not mount debugfs at all. Tracefs reduces the attack surface by allowing to trace without mounting debugfs. Additionally it provides features not supported by debugfs (such as calls for mkdir and rmdir
Debian and Arch Linux both enable this by default.
RHEL 8 and later, they enable tracefs by default.
Signed-off-by: John Titor <50095635+JohnRTitor@users.noreply.github.com>
This makes it so that the getty units are only included if
`config.console.enable` is set to `true`. Previously, they would be
included, but disabled in that case, which is unnecessary.
Prior to this contribution, every boot with a default configuration was
considered `ConditionFirstBoot=true` by systemd, since /etc/machine-id
was not commited to disk.
This also extends the systemd with a check for subsequent boots not
being considered first boots.
In preparation for the deprecation of `stdenv.isX`.
These shorthands are not conducive to cross-compilation because they
hide the platforms.
Darwin might get cross-compilation for which the continued usage of `stdenv.isDarwin` will get in the way
One example of why this is bad and especially affects compiler packages
https://www.github.com/NixOS/nixpkgs/pull/343059
There are too many files to go through manually but a treewide should
get users thinking when they see a `hostPlatform.isX` in a place where it
doesn't make sense.
```
fd --type f "\.nix" | xargs sd --fixed-strings "stdenv.is" "stdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "stdenv'.is" "stdenv'.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "clangStdenv.is" "clangStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "gccStdenv.is" "gccStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "stdenvNoCC.is" "stdenvNoCC.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "inherit (stdenv) is" "inherit (stdenv.hostPlatform) is"
fd --type f "\.nix" | xargs sd --fixed-strings "buildStdenv.is" "buildStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "effectiveStdenv.is" "effectiveStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "originalStdenv.is" "originalStdenv.hostPlatform.is"
```
This adds support for declaring tmpfiles rules exclusively for the
systemd initrd. Configuration is possible through the new option
`boot.initrd.systemd.tmpfiles.settings` that shares the same interface as
`systemd.tmpfiles.settings`.
I did intentionally not replicate the `rules` interface here, given that
the settings attribute set is more versatile than the list of strings
used for `rules`. This should also make it unnecessary to implement the
workaround from 1a68e21d47 again.
A self-contained `tmpfiles.d` directory is generated from the new initrd
settings and it is added to the initrd as a content path at
`/etc/tmpfiles.d`.
The stage-1 `systemd-tmpfiles-setup.service` is now altered to no longer
operate under the `/sysroot` prefix, because the `/sysroot` hierarchy
cannot be expected to be available when the default upstream service is
started.
To handle files under `/sysroot` a slightly altered version of the
upstream default service is introduced. This new unit
`systemd-tmpfiles-setup-sysroot.service` operates only under the
`/sysroot` prefix and it is ordered between `initrd-fs.target` and the
nixos activation.
Config related to tmpfiles was moved from initrd.nix to tmpfiles.nix.
One of the main premises of NixOS is being able to declaratively specify
the services enabled/running on a machine. Since systemd presets allow
to bypass this this declarative nature, add a single preset with the
highest priority (prefixed with "00") that makes systemd ignore all
other presets.
If we let systemd setup /etc/machine-id, we get to use
ConditionFirstBoot in systemd units and any other integrations related
to systemd's detection of first boot. See machine-id(5).
When `services.resolved` is enabled, then `resolve [!UNAVAIL=return]`
is added to `system.nssDatabases.hosts` with priority 501,
which prevents lower-priority NSS modules from running
unless systemd-resolved is not available.
Quoting from `man nss-resolve`:
> To activate the NSS module, add "resolve [!UNAVAIL=return]" to the line
> starting with "hosts:" in /etc/nsswitch.conf. Specifically, it is
> recommended to place "resolve" early in /etc/nsswitch.conf's "hosts:"
> line. It should be before the "files" entry, since systemd-resolved
> supports /etc/hosts internally, but with caching. To the contrary, it
> should be after "mymachines", to give hostnames given to local VMs and
> containers precedence over names received over DNS. Finally, we
> recommend placing "dns" somewhere after "resolve", to fall back to
> nss-dns if systemd-resolved.service is not available.
Note that the man page (just) recommends "early" and means with this
"before the 'files' and 'dns' entries". It does not insist on being
first or excluding other modules.
For this reason, libvirt NSS modules should run before the `resolve`
module. They should come right next to `mymachines` because both are
conceptually very similar -- they resolve local VMs/containers.
Since the data source of the libvirt NSS modules are local
plain text files (see source code of the libvirt NSS module),
no performance impact is expected form this raise of priorities.
Other NSS modules in NixOS also explicitly set their priority, which is
why this change increases consistency.
Fixes#322022
This allows us to set things like dependencies in a way that we can
catch typos at eval time.
So instead of
```nix
systemd.services.foo.wants = [ "bar.service" ];
```
we can write
```nix
systemd.services.foo.wants = [ config.systemd.services.bar.name ];
```
which will throw an error if no such service has been defined.
Not all cases can be done like this (eg template services), but in a lot
of cases this will allow to avoid typos.
There is a matching option on the unit option
(`systemd.units."foo.service".name`) as well.
