Hi Brien, thanks for the great guide!
I want to mention a couple of problems I faced following it. First in production config file port is assigned by default through PORT environment variable. It’s possible to set it in Dockerfile and get rid of misleading MIX_HOST variable. In that case it will be the single place where port is defined.
Another problem corresponded to the VirtualBox port forwarding. By default it forwards only port 22. Therefore port binding when executing `docker run -p 8888:8888` was making no effect. A configuration of the port forwarding in the network settings of a VirtualBox machine solved the problem. Probably it is worth mentioning to save somebody a couple of hairs.