One of the major benefits of Bundler is being able to checkout a project and install its Gem dependencies using the
bundle command. However, Gems that are only used locally shouldn't be added to the Gemfile because they unnecessarily alter Gem dependencies and in some cases create conflicts with project Gems.
I wanted users to be able to easily install my project's toolchain without creating conflicts so I decided to create a separate Gemfile named Gemfile.tools.
source 'https://rubygems.org' gem 'chef' gem 'vagrant', '~>1.0.7' gem 'knife-solo'
To install the Gems from this file you need to run
bundle install --gemfile Gemfile.tools
This will install the Gems and create a new file called Gemfile.tools.lock.
Finally to use the
bundle exec command with the new Gemfile.tools you run
BUNDLE_GEMFILE=Gemfile.tools bundle exec ...
I find this to be a bit cumbersome so the other option is to install the Gems with binstubs
bundle install --gemfile Gemfile.tools --binstubs
Then you can access your gems through your project's bin directory
By creating two separate Gemfiles I was able to harness the power of Bundler while keeping my project and toolchain Gems separate.