Make the Celery module work with Flower.

Flower is the new recommended way to monitor Celery through a
web-API.
http://celery.readthedocs.org/en/latest/userguide/monitoring.html?highlight=flower#flower-real-time-celery-web-monitor

celery/README.md

@@ -9,12 +9,11 @@ from http://docs.celeryproject.org.
 Prerequisite
 ============
 
-Make sure Celery exposes it's API over HTTP e.g.
-
-curl http://localhost:8989/api/worker/
-
-or similar needs to succeed for this module to work.
+This version of the module works with Flower (https://github.com/mher/flower),
+a web-based tool to monitor Celery workers and tasks.
 
+Previous versions of this module worked with Celerymon, which has now been
+obsoleted in favor of Flower (http://celery.readthedocs.org/en/latest/userguide/monitoring.html?highlight=flower#flower-real-time-celery-web-monitor).
 
 Install
 ===============

celery/conf.d/celery.pyconf

@@ -2,9 +2,8 @@ modules {
   module {
     name     = "ganglia_celery"
     language = "python"
-    # Don't forget the trailing slash on the URL
     param url {
-        value = "http://localhost:10000/api/worker/"
+        value = "http://localhost:10000/api/workers"
     }
 
   }

celery/python_modules/ganglia_celery.py

@@ -38,7 +38,7 @@ def get_metrics():
 	    res = urllib2.urlopen(req, None, 1)
 	    stats = res.read()
 	    metrics2 = json.loads(stats)
-            metrics = metrics2[0]
+            metrics = metrics2['celery@{}'.format(socket.gethostname())]
             metrics['status'] = "up"
 
         except StandardError, e:
@@ -148,19 +148,26 @@ def metric_init(params):
     SERVER_STATUS_URL = params["url"]
 
     descriptors.append(create_desc(Desc_Skel, {
-	"name"       : params["metrics_prefix"] + "_active",
+	"name"       : params["metrics_prefix"] + "_running_tasks",
 	"units"      : "jobs",
 	"description": "Number of active jobs",
 	"call_back"  : get_value
     }))
 
     descriptors.append(create_desc(Desc_Skel, {
-	"name"       : params["metrics_prefix"] + "_processed",
+	"name"       : params["metrics_prefix"] + "_completed_tasks",
 	"units"      : "jobs/s",
 	"description": "Number of processed jobs",
 	"call_back"  : get_delta
     }))
 
+    descriptors.append(create_desc(Desc_Skel, {
+        "name"       : params["metrics_prefix"] + "_concurrency",
+        "units"      : "processes/s",
+        "description": "Number of worker processes",
+        "call_back"  : get_value
+    }))
+
     descriptors.append(create_desc(Desc_Skel, {
 	"name"       : params["metrics_prefix"] + "_status",
 	"units"      : "",
@@ -183,7 +190,7 @@ def create_desc(skel, prop):
 if __name__ == '__main__':
     try:
         params = {
-            "url" : "http://localhost:8989/api/worker/",
+            "url" : "http://localhost:10000/api/workers",
             }
         metric_init(params)