LightDM doesn't properly install within a container

[jerbmega]

I've been advised to move this here from fedora-silverblue/issue-tracker#452.

Host system details

No "host" in this case, this is in an OCI build.

Expected vs actual behavior

LightDM is not properly installed when added within a Containerfile.
Adding lightdm in a Containerfile results in a build that succeeds, but cannot properly run LightDM, as the user is not made due to an error. I also get a dbus-daemon error within the container. I've reproduced this on both Fedora 37 and 38.

The package works properly when layering it over an existing installation, implying this is solely a container issue.

I get the following error during build:

error: Found argument '-M' which wasn't expected, or isn't valid in this context

	If you tried to supply `-M` as a value rather than a flag, use `-- -M`

USAGE:
    useradd [OPTIONS] <username>

For more information try --help
Installing: lightdm-1.32.0-2.fc37.x86_64 (fedora)
dbus-daemon: no process found

When running lightdm --debug in the resulting install, the following relevant debug output is noted:

...
[+0.10s] WARNING: Could not enumerate user data directory /var/lib/lightdm-data: Error opening directory `/var/lib/lightdm-data`: No such file or directory
-snip-
[+1.42s] DEBUG: Session pid=1225: Started with service `lightdm-greeter`, username `lightdm`
Failed to get information on user lightdm: Success
[+1.46s] DEBUG: Session pid=1225: Authentication complete with return value 10: User not known to the underlying authentication module
...

Expected:
The LightDM user should be properly set up during the build process.

Steps to reproduce it

• Add rpm-ostree install lightdm into a Containerfile. The build will succeed but will not run properly once deployed, with the above symptoms. This can be reproduced both via a local Podman build as well as Github Actions.

[travier]

Notes from investigation in the parent ticket:

Error opening directory `/var/lib/lightdm-data`: No such file or directory

This should be converted to a tmpfiles.d config file instead of being manually created in the package: https://src.fedoraproject.org/rpms/lightdm/blob/rawhide/f/lightdm.spec#_166

---

error: Found argument '-M' which wasn't expected, or isn't valid in this context

	If you tried to supply `-M` as a value rather than a flag, use `-- -M`

It's unclear to me why this would fail in rpm-ostree while this works in the classic RPM case.

[jerbmega]

It looks like the template Containerfile I started from deletes the contents of /var and /tmp from the container before running a commit, so that much isn't an ostree issue.

[travier]

I've updated my comment. It's expected that /var & /tmp are cleared out as they are not part of the ostree commit. Packages should use systemd tmpfiles.d config files to setup files in those directories.

[jerbmega]

Mobile misclick, sorry