Facebook Canvas url using routes.rb

I'd like my FB canvas app

apps.facebook.com/coolapp

to behave the same as my web app

coolapp.com

I've set up the canvas url in facebook developer page

http://coolapp.com/canvas/

Using Rails 3.1, I'd like t开发者_高级运维o know how I can easily route the /canvas into my app so that going to the first url above does not route outside of the facebook canvas page (and all the resources work as expected).

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Copying the answer from the comments in order to remove this question from the "Unanswered" filter:

stackoverflow.com/a/18028579/156561 i link to how to do all this (2 yrs later) in this question.

~ answer per pjammer