Dear Community
We use Docker on our Compact Controller 100 installations. Docker was installed and activated via WBM > Configuration > Docker. Docker uses the SD card as storage as defined in /etc/docker/daemon.json with the “data-root” configuration key, and we use the internal flash as the boot device.
Over the past few months, we have repeatedly noticed that when restarting (e.g. via SSH command ‘sudo /sbin/reboot’ or via the reboot button in the WBM), the Docker Deamon sometimes does not start cleanly. Sometimes the Deamon still starts, but the containers and images are missing (‘docker ps -a’ returns nothing, ‘docker images ls’ and ‘docker container ls’ also return empty results).
Have other users also experienced this phenomenon and were they able to find a solution to this problem?
Normally, a second reboot is sufficient so that the Docker Deamon runs again as usual when restarted and the containers/images are also output again with the corresponding commands. According to the entry in /etc/rc.d/S99_docker which came with the WBM service installation / activation, the Deamon should only be started at the very end, which is why I do not suspect that relevant service dependencies would be missing.
A further note from our side: In /etc/docker/daemon.json we also have another setting active: “shutdown-timeout”: 180, as our Docker containers need a little more time for their cleanup when shutting down.
If we want to gracefully reboot the system with enough time for the container to stop, we use our own bash script:
/usr/bin/docker stop && PID=$! & wait $PID && /sbin/reboot
We would now like to know how we can find out why the Docker Deamon sometimes fails to find containers/images after a reboot. Are there any specific logs or other clues that could help us with this?
Product: WAGO 751-9301 Compact Controller 100
Firmware revision: 04.01.10(23)
Thanks in advance
