Running Apache under docker is very simple but a little tricky if you’ve never done it before. Here’s an example to get Apache running under Ubuntu 12.04 using a simple Dockerfile.

With Docker 0.4.8 a new ENTRYPOINT feature was added to Docker Builder. This feature allows you to specify a command to run as the default entrypoint for a container. This function can be a bit confusing thanks to the presence of the CMD statement as well and I certainly spent some time scratching my head around why both commands were needed. Now that I understand I see that ENTRYPOINT is maybe one of the most important things to get if you really want to understand what Docker is trying to do.