Verify consistent timestamp format

All timestamps in Vitrage should be of the same format:
'%Y-%m-%dT%H:%M:%SZ'

This is needed so webhooks will know what format to expect.

Change-Id: I27624b28e8aa1770d805ee68982509894522b8e6
Story: 1776181
Task: 28541

vitrage_tempest_plugin/tests/base.py

@@ -12,6 +12,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from datetime import datetime
 import json
 from networkx.readwrite import json_graph
 import six
@@ -314,6 +315,23 @@ class BaseVitrageTempest(base.BaseTestCase):
         self.assertEqual(num_entities, graph.num_vertices())
         self.assertEqual(num_edges, graph.num_edges())
 
+        self._validate_timestamps(graph)
+
+    def _validate_timestamps(self, graph):
+        self._validate_timestamp(graph, VProps.UPDATE_TIMESTAMP)
+        self._validate_timestamp(graph, VProps.VITRAGE_SAMPLE_TIMESTAMP)
+
+    def _validate_timestamp(self, graph, timestamp_name):
+        for vertex in graph.get_vertices():
+            timestamp = vertex.get(timestamp_name)
+            if timestamp:
+                try:
+                    datetime.strptime(timestamp, utils.TIMESTAMP_FORMAT)
+                except ValueError:
+                    self.fail('Unexpected timestamp format of \'%s\' in: %s\n'
+                              'The format should be: %s' %
+                              (timestamp_name, vertex, utils.TIMESTAMP_FORMAT))
+
     @staticmethod
     def _get_value(item, key):
         return utils.uni2str(item[key])

vitrage_tempest_plugin/tests/utils.py

@@ -26,6 +26,8 @@ import subprocess
 
 LOG = logging.getLogger(__name__)
 
+TIMESTAMP_FORMAT = '%Y-%m-%dT%H:%M:%SZ'
+
 
 def get_from_terminal(command):
     proc = os.popen(command)