How to use gems not in a Gemfile when working with bundler?

Question

When using bundler with a project in general and Rails specifically, you have access only to gems defined in your Gemfile. While this makes sense, it can be limiting. Mostly

Answer 1

In ChiliProject we allow users to create a Gemfile.local which is included into the main Gemfile on load. This allows users to specify additional gems without having to change our Gemfile to ease updates.

For that, we have included the following code at the bottom of our Gemfile.

gemfile_local = File.expand_path('Gemfile.local', __dir__)
if File.readable?(gemfile_local)
  puts "Loading #{gemfile_local}..." if $DEBUG
  instance_eval(File.read(gemfile_local))
end

The Gemfile.local itself is excluded from the repository via .gitignore.