I agree with everything here. Docker is amazing for developing things which need servers because it completely removes the game of trying to run multiple servers on your workstation.

For me, Docker "clicked" when I took a legacy PHP webapp, and was able to get the whole thing running in a Dockerized dev environment by setting some links and pulling down a Postgres and PHP container - which I can now launch into with a tmux script which lets me see the debug output of both while I'm developing, live updating while I edit and tinker in Webstorm.

That simply wasn't possible before - not nearly as easily.