TL,DR: The following command will allocate a random port on your machine, and map it to port 1234 inside a container: docker run -p 1234 base — nc -l 1234 Use docker inspect (and look under NetworkSettings) to see which random port was allocated. Good news, everyone! Networking support has been merged. This means that your containers can now talk to the outside world (duh!), and the outside world can talk to them as well.