Serve up paperclip attachments in a cache friendly way

config/example.application.yml

@@ -56,7 +56,7 @@ defaults: &defaults
   gpx_trace_dir: "/home/osm/traces"
   gpx_image_dir: "/home/osm/images"
   # Location of data for attachments
-  attachments_dir: ":rails_root/public"
+  attachments_dir: ":rails_root/public/attachments"
   # Log file to use
   #log_path: ""
   # List of memcache servers to use for caching

config/initializers/paperclip.rb

@@ -0,0 +1,20 @@
+module Paperclip
+  class AssetUrlGenerator < UrlGenerator
+    include Sprockets::Helpers::IsolatedHelper
+    include Sprockets::Helpers::RailsHelper
+
+    def for(style_name, options)
+      url = super(style_name, options)
+
+      if url =~ /^\/assets\/(.*)$/
+        asset_path($1)
+      else
+        url
+      end
+    end
+  end
+end
+
+Paperclip::Attachment.default_options[:url] = "/attachments/:class/:attachment/:id_partition/:style/:fingerprint.:extension"
+Paperclip::Attachment.default_options[:path] = "#{ATTACHMENTS_DIR}/:class/:attachment/:id_partition/:style/:fingerprint.:extension"
+Paperclip::Attachment.default_options[:url_generator] = Paperclip::AssetUrlGenerator