#4 allow querying more than one cloudwatch statistic

tests/test_cloudwatch.py

@@ -69,6 +69,31 @@ def test_cloudwatch_query_one(monkeypatch):
             Statistics=['Average'])
 
 
+def test_cloudwatch_query_one_multiple_statistics(monkeypatch):
+    client = MagicMock()
+    client.get_metric_statistics.return_value = {
+        'Datapoints': [
+            {'Timestamp': 99, 'Average': 111.25, 'Minimum': 1},
+            {'Timestamp': 11, 'Average': 100.25}
+        ]}
+    get = MagicMock()
+    get.return_value.json.return_value = {'region': 'myregion'}
+    monkeypatch.setattr('requests.get', get)
+    monkeypatch.setattr('boto3.client', lambda x, region_name: client)
+    cloudwatch = CloudwatchWrapper()
+    start = datetime.datetime.now()
+    end = start # makes no sense, but works for our test
+    elb_data = cloudwatch.query_one({'LoadBalancerName': 'pierone-1'}, 'Latency', None, 'AWS/ELB', start=start, end=end)
+    assert {'Average': 111.25, 'Minimum': 1} == elb_data
+    assert not client.list_metrics.called
+    client.get_metric_statistics.assert_called_with(Namespace='AWS/ELB', MetricName='Latency',
+            Dimensions=[{'Name': 'LoadBalancerName', 'Value': 'pierone-1'}],
+            StartTime=start,
+            EndTime=end,
+            Period=60,
+            Statistics=['Sum', 'Average', 'Maximum', 'SampleCount', 'Minimum'])
+
+
 def test_cloudwatch_query_one_no_result(monkeypatch):
     client = MagicMock()
     client.get_metric_statistics.return_value = {'Datapoints': []}

zmon_worker_monitor/builtins/plugins/cloudwatch.py

@@ -52,6 +52,12 @@ def query_one(self, dimensions, metric_name, statistics, namespace, period=60, m
         if period < 60 or period % 60 != 0:
             raise ValueError('Period must be greater than and a multiple of 60')
 
+        # special case to gather all types at once
+        if statistics is None:
+            statistics = ['Sum', 'Average', 'Maximum', 'SampleCount', 'Minimum']
+        elif isinstance(statistics, basestring):
+            statistics = [statistics]
+
         end = end or datetime.datetime.utcnow()
         start = start or (end - datetime.timedelta(minutes=minutes))
         if isinstance(dimensions, dict):
@@ -61,11 +67,14 @@ def query_one(self, dimensions, metric_name, statistics, namespace, period=60, m
         response = self.client.get_metric_statistics(Namespace=namespace, MetricName=metric_name,
                                                      Dimensions=dimensions,
                                                      StartTime=start, EndTime=end, Period=period,
-                                                     Statistics=[statistics])
+                                                     Statistics=statistics)
         data_points = sorted(response['Datapoints'], key=lambda x: x["Timestamp"])
         if not data_points:
             return None
-        return data_points[-1][statistics]
+        if len(statistics) == 1:
+            return data_points[-1][statistics[0]]
+        else:
+            return {s: v for s, v in data_points[-1].items() if s in statistics}
 
     def query(self, dimensions, metric_name, statistics='Sum', namespace=None, period=60, minutes=5):
         '''Query one or more metric statistics; allows finding dimensions with wildcards'''