add couchbase support

this is a squash commit of all couchbase commits
from minodes/newrelic-plugin-agent:
- 33c9162
  fix JSON access
- 4e06957
  read basicStats from all couchbase buckets
- eb58aa6
  basicStats now per bucket sent to newrelic
- ede17dc
  add couchbase support

the original branch used in pull request #404 had a bunch
of garbage commits related to other plugins (nagiorelic).

i cleaned the unrelated stuff and squashed everything
to a single commit

README.rst

@@ -7,6 +7,7 @@ NewRelic platform. Currently supported backend systems are:
 - Alternative PHP Cache
 - Apache HTTP Server
 - CouchDB
+- Couchbase
 - Elasticsearch
 - HAProxy
 - Memcached
@@ -298,6 +299,12 @@ Configuration Example
             #username: foo
             #password: bar
 
+      couchbase:
+        name: localhost
+        host: localhost
+        port: 8091
+        path: pools/default/buckets
+
       elasticsearch:
         name: clustername
         host: localhost

docker/base/newrelic-plugin-agent.cfg

@@ -22,6 +22,12 @@ Application:
   #  username: foo
   #  password: bar
 
+  #couchbase:
+  #  name: localhost
+  #  host: localhost
+  #  port: 8091
+  #  path: pools/default/buckets
+
   #elasticsearch:
   #  name: Clustername
   #  host: localhost

etc/newrelic/newrelic-plugin-agent.cfg

@@ -22,6 +22,12 @@ Application:
   #  username: foo
   #  password: bar
 
+  #couchbase:
+  #  name: localhost
+  #  host: localhost
+  #  port: 8091
+  #  path: pools/default/buckets
+
   #elasticsearch:
   #  name: Clustername
   #  host: localhost

newrelic_plugin_agent/plugins/__init__.py

@@ -6,6 +6,7 @@
 available = {
     'apache_httpd': 'newrelic_plugin_agent.plugins.apache_httpd.ApacheHTTPD',
     'couchdb': 'newrelic_plugin_agent.plugins.couchdb.CouchDB',
+    'couchbase': 'newrelic_plugin_agent.plugins.couchbase.Couchbase',
     'edgecast': 'newrelic_plugin_agent.plugins.edgecast.Edgecast',
     'elasticsearch':
         'newrelic_plugin_agent.plugins.elasticsearch.ElasticSearch',

newrelic_plugin_agent/plugins/couchbase.py

@@ -0,0 +1,60 @@
+"""
+couchbase
+
+"""
+
+from newrelic_plugin_agent.plugins import base
+
+
+class Couchbase(base.JSONStatsPlugin):
+
+    GUID = 'com.meetme.couchbase'
+
+    def add_datapoints(self, stats):
+        for bucket_data in stats:
+            bucket_name = bucket_data['name']
+            bucket_stats = bucket_data['basicStats']
+            if bucket_stats:
+                """ Example JSON
+                "basicStats":{
+                    "quotaPercentUsed":7.548735046386719,
+                    "opsPerSec":0,
+                    "diskFetches":0,
+                    "itemCount":2222,
+                    "diskUsed":229366539,
+                    "dataUsed":203511808,
+                    "memUsed":79154224
+                }
+                """
+                self.add_gauge_bucket_metric(
+                    bucket_name, 'quotaPercentUsed', 'percent', bucket_stats['quotaPercentUsed']
+                )
+                self.add_gauge_bucket_metric(
+                    bucket_name, 'opsPerSec', 'ops', bucket_stats['opsPerSec']
+                )
+                self.add_gauge_bucket_metric(
+                    bucket_name, 'diskFetches', 'count', bucket_stats['diskFetches']
+                )
+                self.add_gauge_bucket_metric(
+                    bucket_name, 'itemCount', 'count', bucket_stats['itemCount']
+                )
+                self.add_gauge_bucket_metric(
+                    bucket_name, 'diskUsed', 'Byte', bucket_stats['diskUsed']
+                )
+                self.add_gauge_bucket_metric(
+                    bucket_name, 'dataUsed', 'Byte', bucket_stats['dataUsed']
+                )
+                self.add_gauge_bucket_metric(
+                    bucket_name, 'memUsed', 'Byte', bucket_stats['memUsed']
+                )
+
+                # Summary metrics
+                self.add_gauge_value('Summary/%s/quotaPercentUsed' % bucket_name, 'percent',
+                                     bucket_stats['quotaPercentUsed'],
+                                     min_val=0, max_val=0)
+                self.add_gauge_value('Summary/%s/diskUsed' % bucket_name, 'byte',
+                                     bucket_stats['diskUsed'])
+
+    def add_gauge_bucket_metric(self, bucket_name, metric_name, units, metric_value):
+        if metric_value:
+            self.add_gauge_value('%s/%s' % (bucket_name, metric_name), units, metric_value)