Unify logger and taggedlogging middleware as both address logging concerns.

railties/CHANGELOG

 *Rails 3.2.0 (unreleased)*
 
-* Added Rails::Rack::TaggedLogging middleware by default that will apply any tags set in config.log_tags to the newly ActiveSupport::TaggedLogging Rails.logger. This makes it easy to tag log lines with debug information like subdomain and request id -- both very helpful in debugging multi-user production applications [DHH]
+* Updated Rails::Rack::Logger middleware to apply any tags set in config.log_tags to the newly ActiveSupport::TaggedLogging Rails.logger. This makes it easy to tag log lines with debug information like subdomain and request id -- both very helpful in debugging multi-user production applications [DHH]
 
 * Default options to `rails new` can be set in ~/.railsrc [Guillermo Iguaran]
 

railties/lib/rails/application.rb

@@ -165,8 +165,7 @@ def default_middleware_stack
         middleware.use ::Rack::Runtime
         middleware.use ::Rack::MethodOverride
         middleware.use ::ActionDispatch::RequestId
-        middleware.use ::Rails::Rack::TaggedLogging, config.log_tags
-        middleware.use ::Rails::Rack::Logger # must come after Rack::MethodOverride to properly log overridden methods
+        middleware.use ::Rails::Rack::Logger, config.log_tags # must come after Rack::MethodOverride to properly log overridden methods
         middleware.use ::ActionDispatch::ShowExceptions, config.consider_all_requests_local
         middleware.use ::ActionDispatch::RemoteIp, config.action_dispatch.ip_spoofing_check, config.action_dispatch.trusted_proxies
         if config.action_dispatch.x_sendfile_header.present?

railties/lib/rails/rack.rb

@@ -3,6 +3,5 @@ module Rack
     autoload :Debugger,      "rails/rack/debugger"
     autoload :Logger,        "rails/rack/logger"
     autoload :LogTailer,     "rails/rack/log_tailer"
-    autoload :TaggedLogging, "rails/rack/tagged_logging"
   end
 end

railties/lib/rails/rack/logger.rb

 require 'active_support/core_ext/time/conversions'
+require 'active_support/core_ext/object/blank'
 
 module Rails
   module Rack
     # Log the request started and flush all loggers after it.
     class Logger < ActiveSupport::LogSubscriber
-      def initialize(app)
-        @app = app
+      def initialize(app, tags=nil)
+        @app, @tags = app, tags.presence
       end
 
       def call(env)
-        before_dispatch(env)
-        @app.call(env)
-      ensure
-        after_dispatch(env)
+        if @tags
+          Rails.logger.tagged(compute_tags(env)) { call_app(env) }
+        else
+          call_app(env)
+        end
       end
 
     protected
 
-      def before_dispatch(env)
+      def call_app(env)
         request = ActionDispatch::Request.new(env)
         path = request.filtered_path
-
-        info "\n\n"
-        info "Started #{request.request_method} \"#{path}\" for #{request.ip} at #{Time.now.to_default_s}"
+        Rails.logger.info "\n\nStarted #{request.request_method} \"#{path}\" for #{request.ip} at #{Time.now.to_default_s}"
+        @app.call(env)
+      ensure
+        ActiveSupport::LogSubscriber.flush_all!
       end
 
-      def after_dispatch(env)
-        ActiveSupport::LogSubscriber.flush_all!
+      def compute_tags(env)
+        request = ActionDispatch::Request.new(env)
+
+        @tags.collect do |tag|
+          case tag
+          when Proc
+            tag.call(request)
+          when Symbol
+            request.send(tag)
+          else
+            tag
+          end
+        end
       end
     end
   end

railties/lib/rails/rack/tagged_logging.rb

-module Rails
-  module Rack
-    # Enables easy tagging of any logging activity that occurs within the Rails request cycle. The tags are configured via the
-    # config.log_tags setting. The tags can either be strings, procs taking a request argument, or symbols representing method
-    # names on request (so :uuid will result in request.uuid being added as a tag).
-    class TaggedLogging
-      def initialize(app, tags = nil)
-        @app, @tags = app, tags
-      end
-
-      def call(env)
-        if @tags
-          Rails.logger.tagged(compute_tags(env)) { @app.call(env) }
-        else
-          @app.call(env)
-        end
-      end
-      
-      private
-        def compute_tags(env)
-          request = ActionDispatch::Request.new(env)
-
-          @tags.collect do |tag|
-            case tag
-            when Proc
-              tag.call(request)
-            when Symbol
-              request.send(tag)
-            else
-              tag
-            end
-          end
-        end
-    end
-  end
-end