Update: I found no valid mm container in the docker store.

You can build your own docker image locally with

docker build -t magic_mirror .

and run it with

docker run -d --publish 8080:8080 --restart always --volume ~/magic_mirror/config:/opt/magic_mirror/config --volume ~/magic_mirror/modules:/opt/magic_mirror/modules --name magic_mirror magic_mirror

and open it in your browser with

http://localhost:8080/

Be aware of this issue.

Karsten.