How To Freeze Gems In Rails

Here's how to freeze any gem into your Rails app. This is a simplified version of the larger discussion Vendor Everything at err.the_blog.

1. Copy the gems you want into the directory vendor/gems.

   $ mkdir vendor/gems
   $ cd vendor/gems
   $ gem unpack some_gem_name # repeat for each gem
   

2. Edit config/environment.rb and add the following inside the Rails::Initializer.run block:

   Rails::Initializer.run do |config|
     # add the next three lines
     config.load_paths += Dir["#{RAILS_ROOT}/vendor/gems/**"].map do |dir|
       File.directory?(lib = "#{dir}/lib") ? lib : dir
    end
   end
   

Now you can require those gems in your code, even if the system you are running on doesn't have that gem installed.