Remove requirement for load ordering the gems with resque

RUBY-668 You should be able to specify the contrib gem/agent gem/resque gem in any order in a Gemfile and it should still work. Setting NEWRELIC_DISPATCHER should never be necessary for resque apps.

CHANGELOG

@@ -1,3 +1,9 @@
+* Version 2.1.5
+
+  Changed the resque detection so it does not depend on the load
+  order of resque => rpm_contrib => newrelic_rpm.  The gems can be
+  installed in any order.
+
 * Version 2.1.4
 
   Updated requirements to latest agent with some bug fixes for background jobs

README.md

@@ -12,10 +12,6 @@ For Rails 3.0 and when using Bundler, add these dependencies to your Gemfile:
     gem 'rpm_contrib'
     gem 'newrelic_rpm'
 
-For some frameworks, it's important that the contrib gem is loaded
-before the newrelic_rpm gem.  We hope to remove that unfortunate
-requirement in the future.
-
 For Rails 2.1 and later, add these dependencies to your in your environment.rb:
 
     config.gem 'rpm_contrib'
@@ -39,8 +35,10 @@ after all other frameworks have loaded:
 ### Troubleshooting Startup
 
 If you've set up your gems to load as described above and you are still not seeing 
-data in RPM, try setting the environment variable `NEWRELIC_DISPATCHER` to the name
-of your app server (Camping, Resque, Rake, etc).  
+data in RPM, there may be a bug in detecting your framework.  Try setting the 
+environment variable `NEWRELIC_DISPATCHER` to the name of your app server (Camping, 
+Resque, Rake, etc), and please report to us if this fixes the problem so we can
+fix the auto-detection logic.
 
 If this does not help then set the `log_level` to `debug` in the `newrelic.yml` file
 and examine the `newrelic_agent.log` file for errors after restarting your app.
@@ -65,8 +63,11 @@ You can disable it with `disable_cassandra_instrumentation` in your newrelic.yml
 ### Camping
 
 The gem will detect a Camping app but you need to manually add the
-instrumentation to your configuration file.  See RPMContrib::Instrumentation::Camping 
-for more information.
+instrumentation to your configuration file.  See
+RPMContrib::Instrumentation::Camping for more information. 
+
+In addition you will need to load the gems in the following order: 1) Camping, 2) rpm_contrib,
+3) newrelic_rpm.
 
 ### Crack
 

lib/rpm_contrib.rb

@@ -2,11 +2,7 @@
 
 module RPMContrib; end
 
-# Perform any framework/dispatcher detection before loading the rpm gem.
 require 'rpm_contrib/detection'
-if defined?(::NewRelic) && defined?(::NewRelic::Control)
-  puts "Warning! The rpm_contrib gem should be loaded before the newrelic_rpm gem if you are using Resque or Camping." 
-end
 
 require 'newrelic_rpm'
 require 'rpm_contrib/instrumentation'
@@ -25,7 +21,6 @@ class Railtie < Rails::Railtie
     end
   # Rails 2.x
   elsif defined?(Rails) && Rails.respond_to?(:configuration)
-
     Rails.configuration.after_initialize { NewRelic::Control.instance.init_plugin }
   else
     raise "The rpm_contrib gem supports Rails 2.2+ only."

lib/rpm_contrib/detection.rb

@@ -1,7 +1,5 @@
+# Currently the only framework we are detecting with an agent
+# patch is camping.  You need to specify the camping gem prior
+# to the contrib gem and newrelic agent gem in order for this to work.
 require 'rpm_contrib/detection/camping'
-require 'rpm_contrib/detection/resque'
 
-module RpmContrib
-  module Detection
-  end
-end

lib/rpm_contrib/instrumentation/resque.rb

@@ -54,7 +54,7 @@ module NewRelicInstrumentation; end
     end
 
     ::Resque.before_first_fork do
-      NewRelic::Agent.manual_start(:dispatcher => :resque)
+      NewRelic::Agent.manual_start(:dispatcher => :resque, :sync_startup => true)
     end
 
     ::Resque.after_fork do

test/test_curb.rb

@@ -1,5 +1,8 @@
 require "#{File.dirname(__FILE__)}/helper"
-require 'curb'
+begin
+require 'curb' 
+rescue LoadError
+end
 
 class NewRelic::Agent::NetInstrumentationTest < Test::Unit::TestCase
   include NewRelic::Agent::Instrumentation::ControllerInstrumentation
@@ -63,4 +66,4 @@ def test_ignore
     assert_equal 0, @engine.metrics.size
   end
 
-end
+end if defined? ::Curl::Easy