List Docker commands

$ docker

Verify Docker Version

$ docker --version

Docker system wide information

$ docker info

Resource utilisation statistics

$ docker stats

List all containers (running and non-running)

$ docker ps -a

List running containers

$ docker ps

Stop a container

$ docker stop <container name>

Start a container

$ docker start <container name>

Restart a container

$ docker restart <container name>

Kill a container

$ docker kill <container name>

Remove a container

$ docker rm <container name>

Download Docker container

$ docker pull <image name> 

Eg. 
$ docker pull ubuntu:14.04

List all Downloaded Docker container images

$ docker images

Search Docker images (Eg. tomcat)

$ docker search tomcat