Fix bug of put metric data with timestamp, timestamp should be a date time object instead of a string

moto/cloudwatch/models.py

@@ -2,13 +2,14 @@ import json
 
 from boto3 import Session
 
-from moto.core.utils import iso_8601_datetime_with_milliseconds
+from moto.core.utils import iso_8601_datetime_without_milliseconds
 from moto.core import BaseBackend, BaseModel
 from moto.core.exceptions import RESTError
 from datetime import datetime, timedelta
 from dateutil.tz import tzutc
 from uuid import uuid4
 from .utils import make_arn_for_dashboard
+from dateutil import parser
 
 from moto.core import ACCOUNT_ID as DEFAULT_ACCOUNT_ID
 
@@ -146,7 +147,7 @@ class Dashboard(BaseModel):
 
 class Statistics:
     def __init__(self, stats, dt):
-        self.timestamp = iso_8601_datetime_with_milliseconds(dt)
+        self.timestamp = iso_8601_datetime_without_milliseconds(dt)
         self.values = []
         self.stats = stats
 
@@ -278,8 +279,7 @@ class CloudWatchBackend(BaseBackend):
             # Preserve "datetime" for get_metric_statistics comparisons
             timestamp = metric_member.get("Timestamp")
             if timestamp is not None and type(timestamp) != datetime:
-                timestamp = datetime.strptime(timestamp, "%Y-%m-%dT%H:%M:%S.%fZ")
+                timestamp = parser.parse(timestamp)
-                timestamp = timestamp.replace(tzinfo=tzutc())
             self.metric_data.append(
                 MetricDatum(
                     namespace,

tests/test_cloudwatch/test_cloudwatch.py

@@ -1,5 +1,6 @@
 import boto
 from boto.ec2.cloudwatch.alarm import MetricAlarm
+from datetime import datetime
 import sure  # noqa
 
 from moto import mock_cloudwatch_deprecated
@@ -115,3 +116,33 @@ def test_describe_alarms():
 
     alarms = conn.describe_alarms()
     alarms.should.have.length_of(0)
+
+
+@mock_cloudwatch_deprecated
+def test_get_metric_statistics():
+    conn = boto.connect_cloudwatch()
+
+    metric_timestamp = datetime(2018, 4, 9, 13, 0, 0, 0)
+
+    conn.put_metric_data(
+        namespace='tester',
+        name='metric',
+        value=1.5,
+        dimensions={'InstanceId': ['i-0123456,i-0123457']},
+        timestamp=metric_timestamp
+    )
+
+    metric_kwargs = dict(
+        namespace='tester',
+        metric_name='metric',
+        start_time=metric_timestamp,
+        end_time=datetime.now(),
+        period=3600,
+        statistics=['Minimum']
+    )
+
+    datapoints = conn.get_metric_statistics(**metric_kwargs)
+    datapoints.should.have.length_of(1)
+    datapoint = datapoints[0]
+    datapoint.should.have.key('Minimum').which.should.equal(1.5)
+    datapoint.should.have.key('Timestamp').which.should.equal(metric_timestamp)