Fix the display of updated_at time when using memcache driver.

When using mc driver(set servicegroup_driver=mc), the service reports
state by memcache. but we use 'nova service-list' get the status of
services registered in nova, the 'update_at' time is not the last updated
time not as db driver. so we should get the time in memcache to update the
time in response.
Closes-Bug: #1647269

Change-Id: I1d4763436ad6de2483c39f5fe97fa6e8d283d8a3

nova/api/openstack/compute/services.py

@@ -71,13 +71,15 @@ class ServiceController(wsgi.Controller):
         active = 'enabled'
         if svc['disabled']:
             active = 'disabled'
+        updated_time = self.servicegroup_api.get_updated_time(svc)
+
         service_detail = {'binary': svc['binary'],
                           'host': svc['host'],
                           'id': svc['id'],
                           'zone': svc['availability_zone'],
                           'status': active,
                           'state': state,
-                          'updated_at': svc['updated_at'],
+                          'updated_at': updated_time,
                           'disabled_reason': svc['disabled_reason']}
 
         for field in additional_fields:

nova/servicegroup/api.py

@@ -78,3 +78,7 @@ class API(object):
             return False
 
         return self._driver.is_up(member)
+
+    def get_updated_time(self, member):
+        """Get the updated time from drivers except db"""
+        return self._driver.updated_time(member)

nova/servicegroup/drivers/base.py

@@ -27,3 +27,7 @@ class Driver(object):
     def is_up(self, member):
         """Check whether the given member is up."""
         raise NotImplementedError()
+
+    def updated_time(self, service_ref):
+        """Get the updated time"""
+        raise NotImplementedError()

nova/servicegroup/drivers/db.py

@@ -79,6 +79,10 @@ class DbDriver(base.Driver):
                        'lhb': str(last_heartbeat), 'el': str(elapsed)})
         return is_up
 
+    def updated_time(self, service_ref):
+        """Get the updated time from db"""
+        return service_ref['updated_at']
+
     def _report_state(self, service):
         """Update the state of this service in the datastore."""
 

nova/servicegroup/drivers/mc.py

@@ -17,6 +17,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import iso8601
 from oslo_log import log as logging
 from oslo_utils import timeutils
 
@@ -67,6 +68,21 @@ class MemcachedDriver(base.Driver):
 
         return is_up
 
+    def updated_time(self, service_ref):
+        """Get the updated time from memcache"""
+        key = "%(topic)s:%(host)s" % service_ref
+        updated_time_in_mc = self.mc.get(str(key))
+        updated_time_in_db = service_ref['updated_at']
+
+        if updated_time_in_mc:
+            # Change mc time to offset-aware time
+            updated_time_in_mc = \
+                updated_time_in_mc.replace(tzinfo=iso8601.iso8601.Utc())
+            if updated_time_in_db <= updated_time_in_mc:
+                return updated_time_in_mc
+
+        return updated_time_in_db
+
     def _report_state(self, service):
         """Update the state of this service in the datastore."""
         try:

nova/tests/unit/servicegroup/test_api.py

@@ -60,3 +60,14 @@ class ServiceGroupApiTestCase(test.NoDBTestCase):
         result = self.servicegroup_api.service_is_up(member)
         self.assertIs(result, False)
         driver.is_up.assert_not_called()
+
+    def test_get_updated_time(self):
+        member = {"host": "fake-host",
+                  "topic": "compute",
+                  "forced_down": False}
+        retval = "2016-11-02T22:40:31.000000"
+
+        driver = self.servicegroup_api._driver
+        driver.updated_time = mock.MagicMock(return_value=retval)
+        result = self.servicegroup_api.get_updated_time(member)
+        self.assertEqual(retval, result)

nova/tests/unit/servicegroup/test_db_servicegroup.py

@@ -106,3 +106,14 @@ class DBServiceGroupTestCase(test.NoDBTestCase):
 
     def test_report_state_unexpected_error(self):
         self._test_report_state_error(RuntimeError)
+
+    def test_get_updated_time(self):
+        retval = "2016-11-02T22:40:31.000000"
+        service_ref = {
+            'host': 'fake-host',
+            'topic': 'compute',
+            'updated_at': retval
+        }
+
+        result = self.servicegroup_api.get_updated_time(service_ref)
+        self.assertEqual(retval, result)

nova/tests/unit/servicegroup/test_mc_servicegroup.py

@@ -15,10 +15,12 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import iso8601
 import mock
 
 from nova import servicegroup
 from nova import test
+from oslo_utils import timeutils
 
 
 class MemcachedServiceGroupTestCase(test.NoDBTestCase):
@@ -63,3 +65,29 @@ class MemcachedServiceGroupTestCase(test.NoDBTestCase):
         fn(service)
         self.mc_client.set.assert_called_once_with('compute:fake-host',
                                                    mock.ANY)
+
+    def test_get_updated_time(self):
+        updated_at_time = timeutils.parse_strtime("2016-04-18T02:56:25.198871")
+        service_ref = {
+            'host': 'fake-host',
+            'topic': 'compute',
+            'updated_at': updated_at_time.replace(tzinfo=iso8601.iso8601.Utc())
+        }
+
+        self.mc_client.get.return_value = None
+        self.assertEqual(service_ref['updated_at'],
+                         self.servicegroup_api.get_updated_time(service_ref))
+        self.mc_client.get.assert_called_once_with('compute:fake-host')
+        self.mc_client.reset_mock()
+        retval = timeutils.utcnow()
+        self.mc_client.get.return_value = retval
+        self.assertEqual(retval.replace(tzinfo=iso8601.iso8601.Utc()),
+                         self.servicegroup_api.get_updated_time(service_ref))
+        self.mc_client.get.assert_called_once_with('compute:fake-host')
+        self.mc_client.reset_mock()
+        service_ref['updated_at'] = \
+            retval.replace(tzinfo=iso8601.iso8601.Utc())
+        self.mc_client.get.return_value = updated_at_time
+        self.assertEqual(service_ref['updated_at'],
+                         self.servicegroup_api.get_updated_time(service_ref))
+        self.mc_client.get.assert_called_once_with('compute:fake-host')