What were you trying to do that didn't work?

I am currently debugging a curious bug in cockpit-ostree: after roughly a minute the UI stops updating, as it does not receive any signals from rpm-ostreed any more. Turns out this is because rpm-ostreed.service times out and exits.

Please provide the package NVR for which bug is seen:

rpm-ostree-2024.6-1.el9.x86_64

How reproducible: Always

Steps to reproduce

• Edit /etc/rpm-ostreed.conf to set IdleExitTimeout=10 to iterate faster; the bug exists with the default 60s as well, but iteration takes too long then
• Follow the automatic stopping with

  watch systemctl status rpm-ostreed
  

Now do some D-Bus queries to it in a loop (like once every 2 seconds), like

busctl call org.projectatomic.rpmostree1 /org/projectatomic/rpmostree1 org.freedesktop.DBus.Peer Ping

or more specifically,

busctl call org.projectatomic.rpmostree1 /org/projectatomic/rpmostree1 org.freedesktop.DBus.ObjectManager GetManagedObjects

or even more expensively/specifically:

busctl call org.projectatomic.rpmostree1 /org/projectatomic/rpmostree1/default org.projectatomic.rpmostree1.OS ListRepos

Expected results

As soon as there is a connected D-Bus client (with signal subscriptions), rpm-ostreed should never time out – only after the last client disconnected.

I also expect each D-Bus request to a running daemon to reset the idle timeout.

Actual results

rpm-ostreed.service stops after ~ 10 seconds (it varies, there's some randomness added to it) always, regardless of what you do. I didn't find a way to keep it alive with D-Bus calls.

It also does not even seem to unregister from D-Bus properly, the client doesn't even get a "NameLost" signal that the service went away. E.g. when you pkill -e udisksd, you get this in busctl monitor:

‣ Type=signal  Endian=l  Flags=1  Version=1 Cookie=-1  Timestamp="Thu 2024-07-18 12:28:07.139996 UTC"
  Sender=org.freedesktop.DBus  Destination=:1.158  Path=/org/freedesktop/DBus  Interface=org.freedesktop.DBus  Member=NameLost
  MESSAGE "s" {
          STRING "org.freedesktop.UDisks2";
  };

but this doesn't happen for rpm-ostreed. So there's no way for a client to react to a timeout and re-establish the connection.