Full page caching in Rails with Nginx and Redis

The app I am currently working on is a CMS that allows users to create their own sites. These sites are publicly accessible and do not require authentication or user-customised content, so they are a great candidate for full page caching.Out of the box, Rails comes with several great caching features that make implementing caching very easy in most cases. However for full page caching a gem is required. The functionality to cache entire pages was in fact extracted from Rails into a separate gem a while ago, because cache invalidation with this kind of technique can be tricky and therefore fragment caching is the recommended caching method for most use cases, especially with the "Russian Doll" technique.