fix cloudwatch bug (#1374)

* bugfix + add tests

moto/cloudwatch/models.py

@@ -10,6 +10,8 @@ from .utils import make_arn_for_dashboard
 
 DEFAULT_ACCOUNT_ID = 123456789012
 
+_EMPTY_LIST = tuple()
+
 
 class Dimension(object):
 
@@ -146,14 +148,14 @@ class Statistics:
         return sum(self.values)
 
     @property
-    def min(self):
+    def minimum(self):
         if 'Minimum' not in self.stats:
             return None
 
         return min(self.values)
 
     @property
-    def max(self):
+    def maximum(self):
         if 'Maximum' not in self.stats:
             return None
 
@@ -228,7 +230,7 @@ class CloudWatchBackend(BaseBackend):
     def put_metric_data(self, namespace, metric_data):
         for metric_member in metric_data:
             self.metric_data.append(MetricDatum(
-                namespace, metric_member['MetricName'], float(metric_member['Value']), metric_member['Dimensions.member'], metric_member.get('Timestamp')))
+                namespace, metric_member['MetricName'], float(metric_member['Value']), metric_member.get('Dimensions.member', _EMPTY_LIST), metric_member.get('Timestamp')))
 
     def get_metric_statistics(self, namespace, metric_name, start_time, end_time, period, stats):
         period_delta = timedelta(seconds=period)

moto/cloudwatch/responses.py

@@ -276,27 +276,27 @@ GET_METRIC_STATISTICS_TEMPLATE = """<GetMetricStatisticsResponse xmlns="http://m
       <Datapoints>
         {% for datapoint in datapoints %}
             <Datapoint>
-              {% if datapoint.sum %}
+              {% if datapoint.sum is not none %}
               <Sum>{{ datapoint.sum }}</Sum>
               {% endif %}
 
-              {% if datapoint.average %}
+              {% if datapoint.average is not none %}
               <Average>{{ datapoint.average }}</Average>
               {% endif %}
 
-              {% if datapoint.maximum %}
+              {% if datapoint.maximum is not none %}
               <Maximum>{{ datapoint.maximum }}</Maximum>
               {% endif %}
 
-              {% if datapoint.minimum %}
+              {% if datapoint.minimum is not none %}
               <Minimum>{{ datapoint.minimum }}</Minimum>
               {% endif %}
 
-              {% if datapoint.sample_count %}
+              {% if datapoint.sample_count is not none %}
               <SampleCount>{{ datapoint.sample_count }}</SampleCount>
               {% endif %}
 
-              {% if datapoint.extended_statistics %}
+              {% if datapoint.extended_statistics is not none %}
               <ExtendedStatistics>{{ datapoint.extended_statistics }}</ExtendedStatistics>
               {% endif %}
 

tests/test_cloudwatch/test_cloudwatch.py

@@ -1,5 +1,8 @@
 import boto
 from boto.ec2.cloudwatch.alarm import MetricAlarm
+import boto3
+from datetime import datetime, timedelta
+import pytz
 import sure  # noqa
 
 from moto import mock_cloudwatch_deprecated

tests/test_cloudwatch/test_cloudwatch_boto3.py

@@ -2,6 +2,8 @@ from __future__ import unicode_literals
 
 import boto3
 from botocore.exceptions import ClientError
+from datetime import datetime, timedelta
+import pytz
 import sure   # noqa
 
 from moto import mock_cloudwatch
@@ -137,6 +139,52 @@ def test_alarm_state():
     len(resp['MetricAlarms']).should.equal(2)
 
 
+@mock_cloudwatch
+def test_put_metric_data_no_dimensions():
+    conn = boto3.client('cloudwatch', region_name='us-east-1')
+
+    conn.put_metric_data(
+        Namespace='tester',
+        MetricData=[
+            dict(
+                MetricName='metric',
+                Value=1.5,
+            )
+        ]
+    )
+
+    metrics = conn.list_metrics()['Metrics']
+    metrics.should.have.length_of(1)
+    metric = metrics[0]
+    metric['Namespace'].should.equal('tester')
+    metric['MetricName'].should.equal('metric')
 
 
+@mock_cloudwatch
+def test_get_metric_statistics():
+    conn = boto3.client('cloudwatch', region_name='us-east-1')
+    utc_now = datetime.now(tz=pytz.utc)
 
+    conn.put_metric_data(
+        Namespace='tester',
+        MetricData=[
+            dict(
+                MetricName='metric',
+                Value=1.5,
+            )
+        ]
+    )
+
+    stats = conn.get_metric_statistics(
+        Namespace='tester',
+        MetricName='metric',
+        StartTime=utc_now,
+        EndTime=utc_now + timedelta(seconds=60),
+        Period=60,
+        Statistics=['SampleCount', 'Sum']
+    )
+
+    stats['Datapoints'].should.have.length_of(1)
+    datapoint = stats['Datapoints'][0]
+    datapoint['SampleCount'].should.equal(1.0)
+    datapoint['Sum'].should.equal(1.5)