roll.rb

# Final Countdown
# config.middleware.use Roll
class Roll
  def initialize(app)
    @app = app
  end
  
  def call(env)
    request = Rack::Request.new(env)
    ip = request.ip
    if roll?
      return [302, {'Location' => 'http://www.youtube.com/v/tt_ro2aerQg&autoplay=1&iv_load_policy=3&start=12'}, ["Final Countdown!"]]
    else
      @app.call(env)
    end
  end
  
  private
  def roll?
    (rand(10) == 4)
  end
end

what is line 9 and 10 for? they don't seem used at all...

Line 9 is to get the request object in order to retrieve the ip on line 10, we were originally doing the rick-roll based on IP.

That's not my point. They're not used in that... Though it's easy to see how they could be.

Yes, it's simply 'artifact' and/or a launching point for others to do some very crafty things :)