Add support for bunny gem as a Queue Loop

.gitignore

@@ -8,3 +8,5 @@ spec/rails/tmp
 *.pid
 Gemfile.lock
 .rvmrc
+*.swp
+tags

lib/loops/autoload.rb

@@ -12,6 +12,7 @@ def self.__p(*path) File.join(Loops::LIB_ROOT, 'loops', *path) end
   autoload :Logger,         __p('logger')
   autoload :ProcessManager, __p('process_manager')
   autoload :Queue,          __p('queue')
+  autoload :BunnyQueue,     __p('bunny_queue')
   autoload :Worker,         __p('worker')
   autoload :WorkerPool,     __p('worker_pool')
 

lib/loops/bunny_queue.rb

@@ -0,0 +1,69 @@
+begin
+  require 'bunny'
+rescue LoadError
+  puts "Can't load bunny gem - all queue loops will be disabled!"
+end
+
+require 'timeout'
+
+module Loops
+  class BunnyQueue < Base
+    def self.check_dependencies
+      raise "No bunny gem installed!" unless defined?(Bunny)
+    end
+
+    def run
+      create_client
+
+      config['queue_name'] ||= "/queue/loops/#{name}"
+      config['ack']        ||= false
+      debug "Client created" if @client
+      debug "Subscribing for the queue #{config['queue_name']}..."
+
+      @total_served = 0
+      @channel ||= @client.create_channel
+      debug "Channel created" if @channel
+      @queue   ||= @channel.queue(config['queue_name'])
+      debug "Queue created" if @queue
+
+      @queue.subscribe(:ack => config['ack'], :block => true) do |delivery_info, properties, payload|
+        begin
+          process_message(delivery_info, properties, payload)
+
+          @channel.ack(delivery_info.delivery_tag, false) if config['ack']
+          @total_served += 1
+          if config['max_requests'] && @total_served >= config['max_requests'].to_i
+            disconnect_client_and_exit
+          end
+        rescue => e
+          error "Exception from process message! We won't be ACKing the message."
+          error "Details: #{e} at #{e.backtrace.first}"
+          disconnect_client_and_exit
+        end
+      end
+    rescue => e
+      error "Closing queue connection because of exception: #{e} at #{e.backtrace.first}"
+      disconnect_client_and_exit
+    end
+
+    def process_message(delivery_info, properties, payload)
+      raise "This method process_message(msg) should be overriden in the loop class!"
+    end
+
+  private
+
+    def create_client
+      debug "Create Bunny client..."
+      config['uri'] ||= 'amqp://127.0.0.1:5672'
+
+      @client = Bunny.new(config['uri'])
+      @client.start
+    end
+
+    def disconnect_client_and_exit
+      debug "Unsubscribing..."
+      @client.close
+      exit(0)
+    end
+  end
+end

lib/loops/logger.rb

@@ -68,7 +68,7 @@ def logfile=(logfile)
         when 'stderr' then $stderr
         when IO, StringIO then logfile
         else
-          if Loops.root
+          if Loops.root && logfile
             logfile =~ /^\// ? logfile : Loops.root.join(logfile).to_s
           else
             logfile