Learning Docker: Building yet another Ruby base image

I’ve started the path of learning how to ship a Rails app inside a Docker container. What I noticed today is that when a rails app runs bundle install for the first time, it spends some time (approx. more than two minutes) installing mini_portile. I found out this gem is a dependency of Nokogiri.

Since Nokogiri will be used in most of the Rails apps running in a container, I decided to install the gem in the base image. See how I did it here.