Use Fig and Docker to run a Rails app... without installing Rails 17 January 2014 We're going to use Fig to set up and run a Rails/PostgreSQL app without installing Rails or PostgreSQL—or Ruby, for that matter. To follow along at home, you'll need Fig and Docker (if you're on a Mac, docker-osx has you covered). Clone the (very small) starting repo, or manually create a directory and copy/paste the