DevOps: Puppet, Docker, and Kubernetes

Building a WordPress image – a Dockerfile example

So far we have seen the example of running just one service inside a container. If we want to run an application, which requires us to run one or more services simultaneously, then, either we will need to run them on the same container or run them on different containers and link them together. WordPress is one such example that requires a database and web service.

Docker only likes one process per container running in the foreground. Thus, in order to make Docker happy, we have a controlling process that manages the database and web services. The controlling process, in this case, is supervisord (http://supervisord.org/). This is a trick we are using to make Docker happy.

Again, we will use a Dockerfile ...