I've been working on a Docker wrapper for Moodle for a couple of years. It is a tool that will help plugin developers specifically. Since I created it, I have used it for pretty much every Moodle plugin I need to develop.
It makes composing / building local moodle sites very simple. You can run multiple local moodle sites concurrently via a proxy server (built in).
Today, my company Citricity, is doing a formal release of it. It's open source and free. I sincerely hope that it will be useful to the community: