make memcache-usage configurable

Gemfile

@@ -81,7 +81,7 @@ gem 'rack-protection'
 gem 'syck', :platforms => [:ruby_20, :mingw_20], :require => false
 
 group :production do
-  # we use dalli as standard memcache client remove this if you don't
+  # we use dalli as standard memcache client
   # requires memcached 1.4+
   # see https://github.com/mperham/dalli
   gem 'dalli'

config/configuration.yml.example

@@ -131,6 +131,9 @@ default:
   # see: https://websecuritytool.codeplex.com/wikipage?title=Checks#http-cache-control-header-no-store
   # disable_browser_cache: true
 
+  # use memcache for performance, memcached must be installed
+  # rails_cache_store: :memcache
+
   # Configuration of SCM executable command.
   # Absolute path (e.g. /usr/local/bin/hg) or command name (e.g. hg.exe, bzr.exe)
   # On Windows, *.cmd, *.bat (e.g. hg.cmd, bzr.bat) does not work.

config/environments/development.rb

@@ -66,6 +66,10 @@ OpenProject::Application.configure do
   # Send mails to browser window
   config.action_mailer.delivery_method = :letter_opener
 
-  # we use per process memory for caching in development
+  # default to per process memory for caching in development
+  if OpenProject::Configuration['rails_cache_store'] == :memcache
+    config.cache_store = :dalli_store
+  else
     config.cache_store = :memory_store
   end
+end

config/environments/production.rb

@@ -71,8 +71,10 @@ OpenProject::Application.configure do
   # Use a different logger for distributed setups
   # config.logger = ActiveSupport::TaggedLogging.new(SyslogLogger.new)
 
-  # Use a different cache store in production
+  # rails defaults to :file_store, use :dalli when :memcaches is configured in configuration.yml
+  if OpenProject::Configuration['rails_cache_store'] == :memcache
     config.cache_store = :dalli_store
+  end
 
   # Enable serving of images, stylesheets, and JavaScripts from an asset server
   # config.action_controller.asset_host = "http://assets.example.com"

config/initializers/session_store.rb

@@ -28,8 +28,4 @@
 
 # Be sure to restart your server when you modify this file.
 
-if Rails.env == 'production'
 OpenProject::Application.config.session_store ActionDispatch::Session::CacheStore
-else
-  OpenProject::Application.config.session_store :cookie_store, :key => '_open_project_session'
-end

lib/open_project/configuration.rb

@@ -40,6 +40,8 @@ module OpenProject
       'scm_git_command'         => nil,
       'scm_subversion_command'  => nil,
       'disable_browser_cache'   => true,
+      # default cache_store is :file_store in production and :memory_store in development
+      'rails_cache_store'       => :default,
 
       # email configuration
       'email_delivery_method' => nil,