The Downside to Our Existing Approach

Gem management

We now have a working development environment, completely based on Docker. However, there is one area that is worth a bit more thought: gem management.

Up until now, to install or update gems, we have simply been rebuilding the image for our Rails app. This works because bundle install is one of the steps in our Dockerfile. However, as we will see in a moment, there is a slight downside to this approach compared to what we are used to when managing gems in a non-Dockerized environment.

We will explore an alternative approach to managing our gems, which attempts to avoid the drawback by making different trade-offs (it’s more complicated ...