Added rack logger middleware that tails the environment log

railties/lib/rails/rack.rb

 module Rails
   module Rack
+    autoload :Logger, "rails/rack/logger"
     autoload :Static, "rails/rack/static"
   end
 end

railties/lib/rails/rack/logger.rb

+module Rails
+  module Rack
+    class Logger
+      EnvironmentLog = "#{File.expand_path(Rails.root)}/log/#{Rails.env}.log"
+
+      def initialize(app, log = nil)
+        @app = app
+        @path = Pathname.new(log || EnvironmentLog).cleanpath
+        @cursor = ::File.size(@path)
+        @last_checked = Time.now
+      end
+
+      def call(env)
+        response = @app.call(env)
+        ::File.open(@path, 'r') do |f|
+          f.seek @cursor
+          if f.mtime > @last_checked
+            contents = f.read
+            @last_checked = f.mtime
+            @cursor += contents.length
+            print contents
+          end
+        end
+        response
+      end
+    end
+  end
+end