Along with providing the core tools, Docker also documents an API that allows the core Docker engine to talk to the plugin services written by third-party developers. At the moment, this API allows you to hook your own storage and networking engines into Docker.
This may seem like it is limiting you to a very niche set of plugins, and it is. However, there is a good reason that Docker has taken this decision.
Let's have a look at some of the plugins that we have already installed in the previous chapters; however, rather than covering the functionality, we will take a look at what goes on behind the scenes.