added proxy middleware for preview server functionality

lib/bpm.rb

@@ -16,6 +16,7 @@ module BPM
   autoload :Project,              'bpm/project'
   autoload :PackageProject,       'bpm/package_project'
   autoload :Rack,                 'bpm/rack'
+  autoload :RackProxy,            'bpm/rack_proxy'
   autoload :Server,               'bpm/server'
   autoload :Pipeline,             'bpm/pipeline'
   autoload :DirectiveProcessor,   'bpm/pipeline/directive_processor'

lib/bpm/package.rb

@@ -23,7 +23,8 @@ class Package
       "dependencies:development" => :hash,
       "bpm:build"         => :hash,
       "bpm:use:transport" => :string,
-      "bpm:provides"      => :hash
+      "bpm:provides"      => :hash,
+      "preview_proxy"     => :hash
     }
 
     PLUGIN_TYPES = %w[minifier]

lib/bpm/rack_proxy.rb

@@ -0,0 +1,34 @@
+require 'net/http'
+
+module BPM
+  class RackProxy
+    def initialize(app, project, opts={})
+      mode = opts[:mode] || :debug
+
+      @app = app
+      @proxy = project.preview_proxy
+    end
+
+    def call(env)
+      if env["PATH_INFO"] =~ /^\/#{@proxy['path']}/
+        # puts @app.inspect
+        request = ::Rack::Request.new(env)
+
+        port = @proxy['port'] || (@proxy['use_ssl'] ? 443 : 80)
+
+        http = Net::HTTP.new(@proxy['server'], port)
+        http.use_ssl = @proxy['use_ssl'] || false
+
+        @response = http.start { |http|
+          path = "#{env["REQUEST_PATH"]}?#{env["QUERY_STRING"]}"
+          req = ::Net::HTTP::Get.new(path)
+          http.request(req)        
+        }
+
+        [@response.code, {"Content-Type" => @response.content_type}, [@response.body]]  
+      else
+        @app.call(env)
+      end
+    end
+  end
+end

lib/bpm/server.rb

@@ -32,6 +32,7 @@ def app
       cur_mode    = @mode
 
       @app ||= ::Rack::Builder.new do
+        (use BPM::RackProxy, cur_project, :mode => cur_mode) unless cur_project.preview_proxy.empty?
         use BPM::Rack, cur_project, :mode => cur_mode
         run ::Rack::Directory.new cur_project.root_path
       end.to_app