unicorn-rails is a simple gem that sets the default server for rack (and rails) to unicorn.
unicorn-rails overrides the Rack::Handler.default method to return Rack::Handler::Unicorn which will cause rack (and
rails) to use unicorn by default.
Add this line to your application's Gemfile:
gem "unicorn-rails"
And then execute:
$ bundle install
Just add the gem to your Gemfile and then rails server will default to using unicorn.
Fork, branch & pull request.