This is nice but it's characteristic of most other Docker tutorials which say "just run this command" and don't bother to go into how or why it works. As a resu

This is nice but it's characteristic of most other Docker tutorials which say "just run this command" and don't bother to go into how or why it works. As a result, all the reader can do is copy and paste (if the command even works in the first place or the tutorial isn't out dated). What I think most people need to know is how they can do this but modify the app to work for their purposes instead of just "hello world".