Merge pull request #7838 from guilleiguaran/extract-rack-cache

Disable Rack::Cache by default

actionpack/CHANGELOG.md

@@ -1,5 +1,10 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   The `Rack::Cache` middleware is now disabled by default. To enable it, 
+    set `config.action_dispatch.rack_cache = true` and add `gem rack-cache` to your Gemfile.
+
+    *Guillermo Iguaran*
+
 *   `ActionController::Base.page_cache_extension` option is deprecated
     in favour of `ActionController::Base.default_static_extension`.
 
@@ -13,10 +18,9 @@
 
 *   Failsafe exception returns text/plain. *Steve Klabnik*
 
-*   Remove actionpack's rack-cache dependency and declare the
-    dependency in the Gemfile.
+*   Remove `rack-cache` dependency from Action Pack and declare it on Gemfile
 
-    *Guillermo Iguarán*
+    *Guillermo Iguaran*
 
 *   Rename internal variables on ActionController::TemplateAssertions to prevent
     naming collisions. @partials, @templates and @layouts are now prefixed with an underscore.

actionpack/lib/action_dispatch/railtie.rb

@@ -12,12 +12,7 @@ class Railtie < Rails::Railtie
     config.action_dispatch.rescue_templates = { }
     config.action_dispatch.rescue_responses = { }
     config.action_dispatch.default_charset = nil
-
-    config.action_dispatch.rack_cache = {
-      :metastore => "rails:/",
-      :entitystore => "rails:/",
-      :verbose => false
-    }
+    config.action_dispatch.rack_cache = false
 
     config.action_dispatch.default_headers = {
       'X-Frame-Options' => 'SAMEORIGIN',

railties/lib/rails/application.rb

@@ -297,6 +297,15 @@ def default_middleware_stack #:nodoc:
             error.message << ' Be sure to add rack-cache to your Gemfile'
             raise
           end
+
+          if rack_cache == true
+            rack_cache = {
+              :metastore => "rails:/",
+              :entitystore => "rails:/",
+              :verbose => false
+            }
+          end
+
           require "action_dispatch/http/rack_cache"
           middleware.use ::Rack::Cache, rack_cache
         end

railties/lib/rails/generators/rails/app/templates/Gemfile

@@ -10,7 +10,7 @@ source 'https://rubygems.org'
 <%= javascript_gemfile_entry %>
 
 # Puts a simple HTTP cache in front of your app (and gets you ready for later upgrading to nginx/varnish/squid)
-gem 'rack-cache', '~> 1.2'
+# gem 'rack-cache', '~> 1.2'
 
 # To use ActiveModel has_secure_password
 # gem 'bcrypt-ruby', '~> 3.0.0'

railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt

@@ -14,6 +14,11 @@
   config.consider_all_requests_local       = false
   config.action_controller.perform_caching = true
 
+  # Enable Rack::Cache to put a simple HTTP cache in front of your application
+  # Add `rack-cache` to your Gemfile before enabling this.
+  # For large-scale production use, consider using a caching reverse proxy like nginx, varnish or squid.
+  # config.action_dispatch.rack_cache = true
+
   # Disable Rails's static asset server (Apache or nginx will already do this).
   config.serve_static_assets = false
 

railties/test/application/middleware_test.rb

@@ -56,11 +56,20 @@ def app
       assert !middleware.include?("Rack::Sendfile"), "Rack::Sendfile is not included in the default stack unless you set config.action_dispatch.x_sendfile_header"
     end
 
-    test "Rack::Cache is present when action_controller.perform_caching is set" do
+    test "Rack::Cache is not included by default" do
       add_to_config "config.action_controller.perform_caching = true"
 
       boot!
 
+      assert !middleware.include?("Rack::Cache"), "Rack::Cache is not included in the default stack unless you set config.action_dispatch.rack_cache"
+    end
+
+    test "Rack::Cache is present when action_controller.perform_caching is set and action_dispatch.rack_cache is set" do
+      add_to_config "config.action_controller.perform_caching = true"
+      add_to_config "config.action_dispatch.rack_cache = true"
+
+      boot!
+
       assert_equal "Rack::Cache", middleware.first
     end