11 files changed, 133 insertions, 31 deletions
diff --git a/railties/lib/commands/server.rb b/railties/lib/commands/server.rb
index 7057fcc33f..43b18004c0 100644
--- a/railties/lib/commands/server.rb
+++ b/railties/lib/commands/server.rb
@@ -84,7 +84,7 @@ else
 end
 
 app = Rack::Builder.new {
-  use Rails::Rack::Logger
+  use Rails::Rack::LogTailer unless options[:detach]
   use Rails::Rack::Static
   use Rails::Rack::Debugger if options[:debugger]
   run inner_app
diff --git a/railties/lib/initializer.rb b/railties/lib/initializer.rb
index 56e8ce95ab..637fe74313 100644
--- a/railties/lib/initializer.rb
+++ b/railties/lib/initializer.rb
@@ -155,6 +155,8 @@ module Rails
       initialize_framework_settings
       initialize_framework_views
 
+      initialize_metal
+
       add_support_load_paths
 
       load_gems
@@ -533,6 +535,10 @@ Run `rake gems:install` to install the missing gems.
       end
     end
 
+    def initialize_metal
+      configuration.middleware.use Rails::Rack::Metal
+    end
+
     # Initializes framework-specific settings for each of the loaded frameworks
     # (Configuration#frameworks). The available settings map to the accessors
     # on each of the corresponding Base classes.
@@ -915,6 +921,7 @@ Run `rake gems:install` to install the missing gems.
         # Followed by the standard includes.
         paths.concat %w(
           app
+          app/metal
           app/models
           app/controllers
           app/helpers
@@ -933,6 +940,7 @@ Run `rake gems:install` to install the missing gems.
 
       def default_eager_load_paths
         %w(
+          app/metal
           app/models
           app/controllers
           app/helpers
diff --git a/railties/lib/rails/rack.rb b/railties/lib/rails/rack.rb
index 90535674e9..9705f65e52 100644
--- a/railties/lib/rails/rack.rb
+++ b/railties/lib/rails/rack.rb
@@ -1,7 +1,8 @@
 module Rails
   module Rack
     autoload :Debugger, "rails/rack/debugger"
-    autoload :Logger, "rails/rack/logger"
+    autoload :LogTailer, "rails/rack/log_tailer"
+    autoload :Metal, "rails/rack/metal"
     autoload :Static, "rails/rack/static"
   end
 end
diff --git a/railties/lib/rails/rack/cascade.rb b/railties/lib/rails/rack/cascade.rb
new file mode 100644
index 0000000000..d5af7fc77e
--- /dev/null
+++ b/railties/lib/rails/rack/cascade.rb
@@ -0,0 +1,31 @@
+require 'active_support/ordered_hash'
+
+module Rails
+  module Rack
+    # Try a request on several apps; return the first non-404 response.
+    class Cascade
+      attr_reader :apps
+
+      def initialize(apps)
+        @apps = ActiveSupport::OrderedHash.new
+        apps.each { |app| add app }
+      end
+
+      def call(env)
+        @apps.keys.each do |app|
+          result = app.call(env)
+          return result unless result[0].to_i == 404
+        end
+        Metal::NotFoundResponse
+      end
+
+      def add(app)
+        @apps[app] = true
+      end
+
+      def include?(app)
+        @apps.include?(app)
+      end
+    end
+  end
+end
diff --git a/railties/lib/rails/rack/log_tailer.rb b/railties/lib/rails/rack/log_tailer.rb
new file mode 100644
index 0000000000..a237cee6bc
--- /dev/null
+++ b/railties/lib/rails/rack/log_tailer.rb
@@ -0,0 +1,35 @@
+module Rails
+  module Rack
+    class LogTailer
+      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.to_f
+
+        @file = ::File.open(path, 'r')
+      end
+
+      def call(env)
+        response = @app.call(env)
+        tail_log
+        response
+      end
+
+      def tail_log
+        @file.seek @cursor
+
+        mod = @file.mtime.to_f
+        if mod > @last_checked
+          contents = @file.read
+          @last_checked = mod
+          @cursor += contents.size
+          $stdout.print contents
+        end
+      end
+    end
+  end
+end
diff --git a/railties/lib/rails/rack/logger.rb b/railties/lib/rails/rack/logger.rb
deleted file mode 100644
index 89d02e45a9..0000000000
--- a/railties/lib/rails/rack/logger.rb
+++ /dev/null
@@ -1,28 +0,0 @@
-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
diff --git a/railties/lib/rails/rack/metal.rb b/railties/lib/rails/rack/metal.rb
new file mode 100644
index 0000000000..1df31a1594
--- /dev/null
+++ b/railties/lib/rails/rack/metal.rb
@@ -0,0 +1,27 @@
+require 'rails/rack/cascade'
+
+module Rails
+  module Rack
+    module Metal
+      NotFoundResponse = [404, {}, []].freeze
+      NotFound = lambda { NotFoundResponse }
+
+      class << self
+        def new(app)
+          Cascade.new(builtins + [app])
+        end
+
+        def builtins
+          base = "#{Rails.root}/app/metal"
+          matcher = /\A#{Regexp.escape(base)}\/(.*)\.rb\Z/
+
+          Dir["#{base}/**/*.rb"].sort.map do |file|
+            file.sub!(matcher, '\1')
+            require file
+            file.classify.constantize
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/railties/lib/rails_generator/generators/components/metal/USAGE b/railties/lib/rails_generator/generators/components/metal/USAGE
new file mode 100644
index 0000000000..123ec6c03f
--- /dev/null
+++ b/railties/lib/rails_generator/generators/components/metal/USAGE
@@ -0,0 +1,8 @@
+Description:
+    Cast some metal!
+
+Examples:
+    `./script/generate metal poller`
+
+        This will create:
+            Metal: app/metal/poller.rb
diff --git a/railties/lib/rails_generator/generators/components/metal/metal_generator.rb b/railties/lib/rails_generator/generators/components/metal/metal_generator.rb
new file mode 100644
index 0000000000..64f49d929d
--- /dev/null
+++ b/railties/lib/rails_generator/generators/components/metal/metal_generator.rb
@@ -0,0 +1,8 @@
+class MetalGenerator < Rails::Generator::NamedBase
+  def manifest
+    record do |m|
+      m.directory 'app/metal'
+      m.template 'metal.rb', File.join('app/metal', "#{file_name}.rb")
+    end
+  end
+end
diff --git a/railties/lib/rails_generator/generators/components/metal/templates/metal.rb b/railties/lib/rails_generator/generators/components/metal/templates/metal.rb
new file mode 100644
index 0000000000..e94982b69a
--- /dev/null
+++ b/railties/lib/rails_generator/generators/components/metal/templates/metal.rb
@@ -0,0 +1,12 @@
+# Allow the metal piece to run in isolation
+require(File.dirname(__FILE__) + "/../../config/environment") unless defined?(Rails)
+
+class <%= class_name %>
+  def self.call(env)
+    if env["PATH_INFO"] =~ /^\/<%= file_name %>/
+      [200, {"Content-Type" => "text/html"}, ["Hello, World!"]]
+    else
+      [404, {"Content-Type" => "text/html"}, ["Not Found"]]
+    end
+  end
+end
diff --git a/railties/lib/tasks/middleware.rake b/railties/lib/tasks/middleware.rake
index e0dcf50307..05f159184e 100644
--- a/railties/lib/tasks/middleware.rake
+++ b/railties/lib/tasks/middleware.rake
@@ -1,6 +1,6 @@
 desc 'Prints out your Rack middleware stack'
 task :middleware => :environment do
-  ActionController::Dispatcher.middleware.each do |middleware|
+  ActionController::Dispatcher.middleware.active.each do |middleware|
     puts "use #{middleware.inspect}"
   end
   puts "run ActionController::Dispatcher.new"