Bug#1093002: rng-tools-debian: systemd service fails instead of skipping

[Thorsten Glaser]

On Tue, 14 Jan 2025, Luca Boccassi wrote:

>It looks like this is doing some checks, and intends to skip. But just
>exiting means the service is recorded as failed, and this will likely
>trip other tests, hence the severity to stop migrating to testing for
>now.

Ah, ouch. Agreed.

>There are several ways to do such checks natively _and_ resulting in a
>service that is skipped, rather than failed.

I actually asked you (systemd maintainers in Cc) about this in:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=504044#162

>Or, you could have a special exit status that means the service is
>marked as successful:
>
>https://www.freedesktop.org/software/systemd/man/latest/systemd.service.html#SuccessExitStatus=
>

RestartPreventExitStatus was the one I found and wondered about.

>You could run the script that does the check in an ExecCondition=
>statement - if that fails, the service is marked as skipped.
>
>https://www.freedesktop.org/software/systemd/man/latest/systemd.service.html#ExecCondition=

That’s also an option.

Would you mind looking at the aforementioned mail again, as it
also has other questions, and suggest how we best deal with this?

Additionally… what should we do if no random device is found,
as opposed to quietly not starting if one is found that doesn’t
need rngd to run? The sysvinit script will also just exit 0 in
that case, but it doesn’t have service tracking, and a subsequent
status query will show the dæmon as not running, obviously. I’ve
got no idea how this maps best into the systemd ecosystem, though
I’m currently leaning towards making all the “expected not to start”
conditions the same.

Thanks in advance,
//mirabilos
-- 
[...] if maybe ext3fs wasn't a better pick, or jfs, or maybe reiserfs, oh but
what about xfs, and if only i had waited until reiser4 was ready... in the be-
ginning, there was ffs, and in the middle, there was ffs, and at the end, there
was still ffs, and the sys admins knew it was good. :)  -- Ted Unangst über *fs