Whether you use rails, Sinatra, or Lotus, you don’t really have to think about how cookies and other headers pass from nginx or apache, to the application server and into your app. We’re going to examine this journey in a little more depth. Because it turns out that the story of headers contains a lot of interesting information about the history of the web. http://blog.honeybadger.io/how-cookies-and-other-http-headers-get-passed-from-nginx-to-rack-and-into-rails/