How to login an available running docker
https://www.youtube.com/watch?v=7CmV8fpRYYE
$ docker ps
CONTAINER ID IMAGE
8b0e5e360f4b xxx
$ docker exec -it 8b0e5e360f4b /bin/bash
https://www.youtube.com/watch?v=7CmV8fpRYYE
$ docker ps
CONTAINER ID IMAGE
8b0e5e360f4b xxx
$ docker exec -it 8b0e5e360f4b /bin/bash