It occurred to me the other day, that I should take a look at the middleware I use on this blog. I don't know what it was. My spidey senses just tingled. Boy was I right. I totally had it backwards. Rack middleware is a fantastic thing. It's like a little encapsulated rack application that you can use to filter, process, or otherwise mess with responses. There is middleware to add etags, configure caching, catch and log exceptions, deal with coo…