Using --restart=always
policy will handle restart of existing containers in case of reboot.
The problem is that if there are multiple containers with --restart=always
when you run image of a newer version as discussed in docker - how do you disable auto-restart on a container?.
Trying to automatically remove the container when it exist by put
option docker run --rm
will also problem with the --restart=always
policy since they are conflicting each others.
$ docker run --rm --restart always <image>
Conflicting options: --restart and --rm
So in this case it is better to choose another option: --restart unless-stopped policy.
$ docker run --rm --restart unless-stopped <image>
This policy will not conflicting the docker run --rm
but as explained in docker documentation:
It similar to --restart=always
, except that when the container is stopped
(manually or otherwise), it is not restarted even after Docker daemon
restarts.
So when using this --restart unless-stopped
policy, to ensure the restarting is working in case it stop by accident when you close the terminal, do once in another terminal as below:
$ docker ps
$ docker restart <container>
Wait until the killing process end in the previous shell, then close it and just leave (don't do exit).
And check again in the remained terminal if the container is still running:
$ docker ps
If it is still running the you can safely reboot and check again that the application is restarting and see your docker is clean without unused of multiple containers.