Docker (-ce) not starting anymore after Ubuntu patching. (panic:interface conversion)

General
1

Hello All,

since apt-upgrading my Ubuntu 22.04.01 LTS yesterday docker-ce won’t start anymore.
I could restore a backup from a week before but
a) I would lose a bit of data and work, and
b) I wouldn’t learn anything from it :smiley:

× docker.service - Docker Application Container Engine
     Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
     Active: failed (Result: exit-code) since Thu 2023-02-09 07:41:33 CET; 9min ago
TriggeredBy: × docker.socket
       Docs: https://docs.docker.com
    Process: 3075 ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock (code=exited, status=2)
   Main PID: 3075 (code=exited, status=2)
        CPU: 197ms

Feb 09 07:41:33 vmXYZ systemd[1]: docker.service: Scheduled restart job, restart counter is at 3.
Feb 09 07:41:33 vmXYZ systemd[1]: Stopped Docker Application Container Engine.
Feb 09 07:41:33 vmXYZ systemd[1]: docker.service: Start request repeated too quickly.
Feb 09 07:41:33 vmXYZ systemd[1]: docker.service: Failed with result 'exit-code'.
Feb 09 07:41:33 vmXYZ systemd[1]: Failed to start Docker Application Container Engine.

The error I can make out in the log is

[...]
Feb 09 07:41:31 vmXYZ dockerd[3075]: time="2023-02-09T07:41:31.398671013+01:00" level=info msg="Loading containers: start."
Feb 09 07:41:31 vmXYZ dockerd[3075]: panic: interface conversion: interface {} is nil, not string
Feb 09 07:41:31 vmXYZ dockerd[3075]: goroutine 1 [running]:
Feb 09 07:41:31 vmXYZ dockerd[3075]: github.com/docker/docker/libnetwork/drivers/ipvlan.(*configuration).UnmarshalJSON(0xc000cc2510, {0xc000612b40, 0xee, 0xee})
[...]

And later exiting with:

 docker.service: Main process exited, code=exited, status=2/INVALIDARGUMENT
Feb 09 07:41:31 vmXYZ systemd[1]: docker.service: Failed with result 'exit-code'.
Feb 09 07:41:31 vmXYZ systemd[1]: Failed to start Docker Application Container Engine.
Feb 09 07:41:33 vmXYZ systemd[1]: docker.service: Scheduled restart job, restart counter is at 3.
Feb 09 07:41:33 vmXYZ systemd[1]: Stopped Docker Application Container Engine.
Feb 09 07:41:33 vmXYZ systemd[1]: docker.service: Start request repeated too quickly.
Feb 09 07:41:33 vmXYZ systemd[1]: docker.service: Failed with result 'exit-code'.
Feb 09 07:41:33 vmXYZ systemd[1]: Failed to start Docker Application Container Engine.

When I was done with my Post I realized, that i tokk the 3rd restart attempt from the log.
I checked and it’s still the same error for the first one (without the “repeated to quickly” part).

I hope anyone can help.

Thanks
Chris

2

If you use panic: interface conversion: interface {} is nil, not string as search string in the forum search, you get another topic, where the root cause is identified and a link to a github issue is provided that explains how to remediate the situation.

3

Thanks, I honestly searched in google up and down, but indeed did not use the search in here.

The downgrade to the last known good version worked,
I suppose the rest (removing ipvlan → upgrade → adding ipvlan back in) will work as well.

Thanks again @meyay

4

Actually, you don’t need to downgrade if you are on 23.0.0, just stop the engine, delete the file mentioned, restart the engine and re-create all user defined networks you need.

5

This is fixed in 23.0.1.