Fix an error when generating a host ID

When instance action events are created by periodic tasks,
the project IDs of them become null (None).
It causes an error when 'hostId' is generated
in the "Show Server Action Details"
(GET /servers/{server_id}/os-instance-actions/{request_id})
API.

Fix the issue by using the project ID of the server
if the project ID of the event is None.

Conflicts:
    nova/tests/unit/api/openstack/compute/test_instance_actions.py

    The conflicts are due to not having the following
    changes in Rocky.

    I7f5f08691ca3f73073c66c29dddb996fb2c2b266
    If91c179e3823c8b0da744a9363906b0f7b05c326
    I44546bc9798708a48a250cc3a21bdbcabe2649e1

Change-Id: Iac07fcddd4cc3321c6efe702066eb8af6a875418
Closes-Bug: #1817542
(cherry picked from commit 31fe7c7600)

nova/api/openstack/compute/instance_actions.py

@@ -163,8 +163,15 @@ class InstanceActionsController(wsgi.Controller):
         if show_events:
             events_raw = self.action_api.action_events_get(context, instance,
                                                            action_id)
+            # NOTE(takashin): The project IDs of instance action events
+            # become null (None) when instance action events are created
+            # by periodic tasks. If the project ID is null (None),
+            # it causes an error when 'hostId' is generated.
+            # If the project ID is null (None), pass the project ID of
+            # the server instead of that of instance action events.
             action['events'] = [self._format_event(
-                evt, action['project_id'], show_traceback=show_traceback,
+                evt, action['project_id'] or instance.project_id,
+                show_traceback=show_traceback,
                 show_host=show_host, show_hostid=show_hostid
             ) for evt in events_raw]
         return {'instanceAction': action}

nova/tests/unit/api/openstack/compute/test_instance_actions.py

@@ -14,6 +14,7 @@
 #    under the License.
 
 import copy
+import datetime
 
 import mock
 from oslo_policy import policy as oslo_policy
@@ -31,6 +32,8 @@ from nova import test
 from nova.tests.unit.api.openstack import fakes
 from nova.tests.unit import fake_server_actions
 from nova.tests import uuidsentinel as uuids
+from nova import utils
+
 
 FAKE_UUID = fake_server_actions.FAKE_UUID
 FAKE_REQUEST_ID = fake_server_actions.FAKE_REQUEST_ID1
@@ -314,7 +317,65 @@ class InstanceActionsTestV258(InstanceActionsTestV251):
                       six.text_type(ex))
 
 
-class InstanceActionsTestV262(InstanceActionsTestV251):
+class InstanceActionsTestV262(InstanceActionsTestV258):
     wsgi_api_version = "2.62"
     expect_event_hostId = True
     expect_event_host = True
+    instance_project_id = '26cde4489f6749a08834741678df3c4a'
+
+    def fake_get(self, context, instance_uuid, expected_attrs=None,
+                 cell_down_support=False):
+        return objects.Instance(uuid=instance_uuid,
+                                project_id=self.instance_project_id)
+
+    @mock.patch.object(compute_api.InstanceActionAPI, 'action_events_get')
+    @mock.patch.object(compute_api.InstanceActionAPI,
+                       'action_get_by_request_id')
+    def test_get_action_with_events_project_id_none(self, mock_action_get,
+                                                    mock_action_events):
+        fake_request_id = 'req-%s' % uuids.req1
+
+        mock_action_get.return_value = objects.InstanceAction(
+            id=789,
+            action='stop',
+            instance_uuid=uuids.instance,
+            request_id=fake_request_id,
+            user_id=None,
+            project_id=None,
+            start_time=datetime.datetime(2019, 2, 28, 14, 28, 0, 0),
+            finish_time=None,
+            message='',
+            created_at=None,
+            updated_at=None,
+            deleted_at=None,
+            deleted=False)
+
+        mock_action_events.return_value = [
+            objects.InstanceActionEvent(
+                id=5,
+                action_id=789,
+                event='compute_stop_instance',
+                start_time=datetime.datetime(2019, 2, 28, 14, 28, 0, 0),
+                finish_time=datetime.datetime(2019, 2, 28, 14, 30, 0, 0),
+                result='Success',
+                traceback='',
+                created_at=None,
+                updated_at=None,
+                deleted_at=None,
+                deleted=False,
+                host='host2')]
+
+        req = self._get_http_req('os-instance-actions/1',
+                                 use_admin_context=True)
+        res_dict = self.controller.show(req, uuids.instance, fake_request_id)
+
+        # Assert that 'project_id' is null (None) in the response
+        self.assertIsNone(res_dict['instanceAction']['project_id'])
+        self.assertEqual('host2',
+                         res_dict['instanceAction']['events'][0]['host'])
+        # Assert that the 'hostId' is based on 'host' and the project ID
+        # of the server
+        self.assertEqual(utils.generate_hostid(
+            res_dict['instanceAction']['events'][0]['host'],
+            self.instance_project_id),
+            res_dict['instanceAction']['events'][0]['hostId'])