Setting up Bundler for a Rails 2.3 application

Requirements

• Ruby >= 1.8.6
• Rubygems >= 1.3.5
• Rails >= 2.3.4
• Bundler 0.7.0

Setup bundler to provide all necessary gems

Create the file Gemfile in your RAILS_ROOT and add the following lines:

bundle_path "vendor/bundler_gems"
gem "rails"
disable_system_gems

Including extra Gemfiles?

To make sure bundler handles all the required gems including the ones from plugins use the following code:

my_gemfile = File.join(File.dirname(__FILE__), 'vendor', 'plugins', 'my_plugin', 'Gemfile')
instance_eval(File.read(my_gemfile), my_gemfile)

Create initializer for Bundler

Create file called config/preinitializer.rb and add the follwoing line:

require "#{File.dirname(__FILE__)}/../vendor/bundler_gems/environment"

Initialize Bundler before Rails boots

Add the following to config/boot.rb, just before the Rails.boot! statement.

# for bundler
class Rails::Boot
  def run
    load_initializer
    extend_environment
    Rails::Initializer.run(:set_load_path)
  end
  def extend_environment
    Rails::Initializer.class_eval do
      old_load = instance_method(:load_environment)
      define_method(:load_environment) do
        Bundler.require_env RAILS_ENV
        old_load.bind(self).call
      end
    end
  end
end

Bundle your gems

gem bundle

Using git?

If you're using git we advise you to put the following lines in your .gitignore

vendor/bundler_gems/doc
vendor/bundler_gems/environment.rb
vendor/bundler_gems/gems
vendor/bundler_gems/specifications