To ssh into container:
docker exec -it <container id> /bin/bash
Remove all old images:
docker rmi $(docker images | grep "^<none>" | awk '{print $3}')
Remove all old containers:
docker rm `docker ps --no-trunc -aq`
Stop all running containers
docker stop $(docker ps -aq)
Remove any dangling volumes
docker volume rm $(docker volume ls -qf dangling=true)
Cleanup System
docker system prune -a