passenger-rails-server is a simple gem that sets the default server for rack (and rails) to phusion passenger.

passenger-rails-server overrides the Rack::Handler.default method to return Rack::Handler::Passenger which will cause rack (and rails) to use passenger by default.

Add this line to your application's Gemfile:

gem "passenger-rails-server"

And then execute:

$ bundle install

Just add the gem to your Gemfile and then rails server will default to using passenger.

https://github.com/samuelkadolph/unicorn-rails

Fork, branch & pull request.