2 files changed, 9 insertions, 12 deletions
diff --git a/railties/lib/rails/application/configuration.rb b/railties/lib/rails/application/configuration.rb
index 2c7ddd86e7..17763b39c5 100644
--- a/railties/lib/rails/application/configuration.rb
+++ b/railties/lib/rails/application/configuration.rb
@@ -97,12 +97,16 @@ module Rails
         self
       end
 
-      # Loads and returns the contents of the #database_configuration_file. The
-      # contents of the file are processed via ERB before being sent through
-      # YAML::load.
+      # Loads and returns the configuration of the database.
+      # First, looks at If ENV['DATABASE_URL'] if it's not present it uses the #paths["config/database"]
+      # The contents of the file are processed via ERB before being sent through YAML::load. 
       def database_configuration
-        require 'erb'
-        YAML.load ERB.new(IO.read(paths["config/database"].first)).result
+        if ENV['DATABASE_URL']
+          {Rails.env => ActiveRecord::ConnectionAdapters::ConnectionSpecification::Resolver.connection_url_to_hash(ENV['DATABASE_URL']).stringify_keys}
+        else
+          require 'erb'
+          YAML.load ERB.new(IO.read(paths["config/database"].first)).result
+        end
       rescue Psych::SyntaxError => e
         raise "YAML syntax error occurred while parsing #{paths["config/database"].first}. " \
               "Please note that YAML must be consistently indented using spaces. Tabs are not allowed. " \
diff --git a/railties/lib/rails/application/finisher.rb b/railties/lib/rails/application/finisher.rb
index 872d78d9a4..3ae60312c5 100644
--- a/railties/lib/rails/application/finisher.rb
+++ b/railties/lib/rails/application/finisher.rb
@@ -89,13 +89,6 @@ module Rails
           ActionDispatch::Reloader.to_cleanup(&callback)
         end
       end
-
-      # Disable dependency loading during request cycle
-      initializer :disable_dependency_loading do
-        if config.eager_load && config.cache_classes
-          ActiveSupport::Dependencies.unhook!
-        end
-      end
     end
   end
 end