Uninstalling docker-ce RPM does not disable docker.socket

[ruizink]

The docker-ce rpm package does not cleanup the docker.socket unit from systemd on uninstall.

This makes it so that docker.socket keeps in an active state, despite the socket not being functional:

# systemctl status docker.socket
● docker.socket
   Loaded: not-found (Reason: Unit docker.socket not found.)
   Active: active (listening) since Thu 2023-02-23 22:57:22 UTC; 33s ago
    Tasks: 0 (limit: 25092)
   Memory: 264.0K
   CGroup: /system.slice/docker.socket

Feb 23 22:57:22 751cf9ad8325 systemd[1]: Starting Docker Socket for the API.
Feb 23 22:57:22 751cf9ad8325 systemd[1]: Listening on Docker Socket for the API.
Feb 23 22:57:53 751cf9ad8325 systemd[1]: docker.socket: Socket unit configuration has changed while unit has been running, no open socket file descriptor left. The socket unit is not functional until restarted.

This is a silent trap for the next time we start the service after reinstallation, because socket activation won't work:

# journalctl -u docker.service

Feb 23 23:03:37 751cf9ad8325 systemd[1]: Starting Docker Application Container Engine...
Feb 23 23:03:38 751cf9ad8325 dockerd[19450]: time="2023-02-23T23:03:38.028768000Z" level=info msg="Starting up"
Feb 23 23:03:38 751cf9ad8325 dockerd[19450]: failed to load listeners: no sockets found via socket activation: make sure the service was started by systemd
Feb 23 23:03:38 751cf9ad8325 systemd[1]: docker.service: Main process exited, code=exited, status=1/FAILURE
Feb 23 23:03:38 751cf9ad8325 systemd[1]: docker.service: Failed with result 'exit-code'.
Feb 23 23:03:38 751cf9ad8325 systemd[1]: Failed to start Docker Application Container Engine.
Feb 23 23:03:40 751cf9ad8325 systemd[1]: docker.service: Service RestartSec=2s expired, scheduling restart.
Feb 23 23:03:40 751cf9ad8325 systemd[1]: docker.service: Scheduled restart job, restart counter is at 1.
Feb 23 23:03:40 751cf9ad8325 systemd[1]: Stopped Docker Application Container Engine.

[corhere]

The deb package is also affected: moby/moby#45059

[thaJeztah]

@corhere for deb, the fix was in #686 but we had to revert it for older Ubuntu LTS versions (18.04); #699

[ruizink]

Hello.
Can we get an update on this issue?
Thanks

[thaJeztah]

I think this should be fixed through

• [master] Update "deb" packaging to use "dh_installsystemd", and remove upstart script #914

Which re-applied the original fix (now that Ubuntu 18.04 reached EOL); @ruizink were you still seeing this issue, and if so on what version of docker (and what distro)?

[ruizink]

This is an issue related with the RPM package, not deb.
I've updated the title for clarity.
#852 should fix the issue, but it's still pending review.

[thaJeztah]

🤦‍♂️ doh! Sorry for that, jumping between too many tickets, and thought this was about the deb issue