Add a new Ruby version

The Ruby language is a core part of GOV.UK - most of our applications are written in it.

Managing different versions of Ruby

Each app can use whatever version of Ruby it wants. We manage this with rbenv.

We set up rbenv differently depending on what’s going on:

Interactive login shells: /etc/profile.d/rbenv.sh sets up rbenv
Applications: govuk_setenv and a .ruby-version in the app directory set up rbenv
Deployment: Capistrano uses a non -login shell so we set default_environment (commit)
Testing: Jenkins uses a non-login shell so we add /usr/lib/rbenv/shims to the PATH
Cronjobs: some cronjobs start with /bin/bash -l -c which runs a login shell

You will need to build a new fpm package with the new Ruby version.