gistfile1.rb

# production.rb
...

  config.middleware.use Rack::Cache
  
  # Deflater is inserted here so gzipped assets aren't cached
  config.middleware.insert_before Rack::Cache, Rack::Deflater
  config.middleware.insert_after(Rack::Cache, Rack::ReverseProxy) do
    reverse_proxy_options :preserve_host => true
    reverse_proxy '/blog', 'http://bighorse.net'
  end
  
  # https://devcenter.heroku.com/articles/rack-cache-memcached-static-assets-rails31#configure-rails-cachestore
  config.action_dispatch.rack_cache = {
    :metastore    => Dalli::Client.new,
    :entitystore  => 'file:tmp/cache/rack/body',
    :allow_reload => false
  }

...