Creating containers

Launching a container is simple, as docker run passes the image name you would like to run and the command to run this within the container. If the image doesn't exist on your local machine, Docker will attempt to fetch it from the public image registry:

$ sudo docker run --name hello_world ubuntu /bin/echo hello world  

In the preceding example, the container will start, print hello world, and then stop. Containers are designed to stop once the command executed within them has exited.

As an example, let's run a container using the latest image in Ubuntu. The combination of the -i and -t switches gives you interactive shell access to the container:

$ sudo docker run -it ubuntu
root@a5b3bce6ed1b:/# ls
bin  boot  dev  etc  home  lib  lib64  media  mnt  opt  proc  root  
run  sbin  srv  sys  tmp  usr  var