It turns out that checking for the last mount time of an ext4 file
system isn't a very reliable way to check whether the file system was
properly unmounted.
When creating that test in the first place (88530e02b6),
I was reluctant to inspect the file system when the VM is down and was
searching for a way to check for a clean unmount *after* the file system
was mounted again to make sure we don't need to create a 512 MB raw
image on the host.
Fortunately however, when converting from qcow2, qemu-img actually
writes a sparse file, so for most file systems (that is, file systems
supporting sparse files) this shouldn't waste a lot of disk space.
So when investigating the flakiness, I found that whenever the test is
failing, the unmount of /test-x-initrd-mount was done *before* the final
step during which systemd remounts+unmounts all the remaining file
systems.
I haven't investigated why this is the case, but the test is a
regression test for https://github.com/NixOS/nixpkgs/issues/35268, which
actually didn't unmount the file system *at* *all*, so really all we
need to take care here is whether the unmount has happened and not
*how*.
To make sure that checking the filesystem state is enough for this, I
temporarily replaced the $machine->shutdown call with $machine->crash
and verified that the file system state is "not clean".
Signed-off-by: aszlig <aszlig@nix.build>
Fixes: https://github.com/NixOS/nixpkgs/issues/67555
Updated to the latest version of the nixos-v237 branch, which fixes two
things:
* Make sure that systemd looks in /etc for configuration files.
https://github.com/NixOS/systemd/pull/15
* Fix handling of the x-initrd.mount option.
https://github.com/NixOS/systemd/pull/16
I've added NixOS VM tests for both to ensure we won't run into
regressions. The newly added systemd test only tests for that and is by
no means exhaustive, but it's a start.
Personally I only wanted to fix the former issue, because that's the one
I've been debugging. After sending in a pull request for our systemd
fork (https://github.com/NixOS/systemd/pull/17) I got a notice from
@Mic92, that he already fixed this and his fix was even better as it's
even suitable for upstream (so we hopefully can drop that patch
someday).
The reason why the second one came in was simply because it has been
merged before the former, but I thought it would be a good idea to have
tests for that as well.
In addition I've removed the sysconfdir=$out/etc entry to make sure the
default (/etc) is used. Installing is still done to $out, because those
directories that were previously into sysconfdir now get into
factoryconfdir.
Quote from commit NixOS/systemd@98067cc806:
By default systemd should read all its configuration from /etc.
Therefore we rely on -Dsysconfdir=/etc in meson as default value.
Unfortunately this would also lead to installation of systemd's own
configuration files to `/etc` whereas we are limited to /nix/store. To
counter that this commit introduces two new configuration variables
`factoryconfdir` and `factorypkgconfdir` to install systemd's own
configuration into nix store again, while having executables looking
up files in /etc.
Tested this change against all of the NixOS VM tests we have in
nixos/release.nix. Between this change and its parent no new tests were
failing (although a lot of them were flaky).
Signed-off-by: aszlig <aszlig@nix.build>
Cc: @Mic92, @tk-ecotelecom, @edolstra, @fpletz
Fixes: #35415
Fixes: #35268
