I set up a fresh Alpine Linux 3.23 system with 4 GB of RAM and a 5 GB disk under Proxmox 9.2. Docker 29.5.2 is installed, but the daemon exits immediately with return code 1, and /run/docker.sock is never created. A similar Alpine system works with Docker 29.1.3, so I initially suspected a package or environment difference. I followed the same installation steps on both systems. What should I check to find the cause?
2 Answers
Make sure the OpenRC service is enabled and started with `rc-update add docker` followed by `rc-service docker start`. However, if the service is already attempting to launch, the next step is definitely to inspect the Docker log rather than focusing on the missing socket—the socket is created only after dockerd starts successfully.
The supervise-daemon message only confirms that dockerd crashed; it does not show the actual reason. Running `dockerd --debug` or checking `/var/log/docker.log` should reveal the configuration or startup error. Also verify whether the Proxmox guest is a full VM or an LXC container, since Docker needs the right kernel and container features. Disk space, overlay support, and networking modules are worth checking too.
The Docker log showed the real problem: `invalid character ':' after top-level value` while reading `/etc/docker/daemon.json`. I had removed most of the bad content but left one character behind. After cleaning up the file, the daemon started normally.