DG MS; add rack-rewrite to handle forwarding old urls [ci skip]

Gemfile

@@ -31,6 +31,7 @@ gem "rpm_contrib", "~> 2.1.7"
 
 group :production do # we don't install these on travis to speed up test runs
   gem 'rack-ssl', :require => 'rack/ssl'
+  gem 'rack-rewrite', '~> 1.2.1', :require => false
   gem 'rack-google-analytics', :require => 'rack/google-analytics'
   gem 'rack-piwik', :require => 'rack/piwik'
 end

Gemfile.lock

@@ -298,6 +298,7 @@ GEM
     rack-mount (0.6.14)
       rack (>= 1.0.0)
     rack-piwik (0.1.2)
+    rack-rewrite (1.2.1)
     rack-ssl (1.3.2)
       rack
     rack-test (0.5.7)
@@ -487,6 +488,7 @@ DEPENDENCIES
   pg
   rack-google-analytics
   rack-piwik
+  rack-rewrite (~> 1.2.1)
   rack-ssl
   rails (= 3.0.11)
   rails-i18n

config/application.yml.example

@@ -180,6 +180,8 @@ defaults: &defaults
   # with other pods
   circumvent_ssl_requirement: false
 
+  image_redirect_url: ''
+  
   # Web tracking
 
   # google analytics key - if false, no javascript included

config/initializers/set_up_image_redirects.rb

@@ -0,0 +1,7 @@
+if AppConfig[:image_redirect_url].present?
+  require 'rack-rewrite'
+
+  Rails.application.config.middleware.insert(0, Rack::Rewrite) do
+    r301 %r{/uploads/images/(.*)}, "#{AppConfig[:image_redirect_url]}/uploads/images/$1"
+  end
+end