I'm wondering if there is any way to get the Rails webserver (thin) to serve the *.gz files the asset pipeline creates. As I understand, those have a higher compression level than that of Rack::Deflater, which only works with serve_static_assets from within the rackup file and not in config.middleware.
A less optimal solution might be to change the default compression level of Zlib which is what Rack::Deflater references. It should only need to gzip once, then it goes to Rack::Cache, then hopefully a CDN.
A second less optimal solution might be a Rack::Rewrite.
The answer to your question can be found at https://gist.github.com/2152663.
There's an easier way using a small gem to do this.
Here's article that explains how: http://www.cheynewallace.com/serving-compressed-assets-with-heroku-rack-zippy/
Use this gem github.com/mattolson/heroku_rails_deflate
来源：https://stackoverflow.com/questions/12326191/any-way-to-serve-gzip-assets-from-heroku