Add a regression test for ImagePropsWeigher

The weigher is unable to get the right image metadata for existing instances if they are not already on the HostState. Change-Id: I5bccf854662ecffe1d469bacc6e4afcb746d6b4d Signed-off-by: Sylvain Bauza <sbauza@redhat.com>
2025-10-06 14:36:53 +02:00
parent b99a882366
commit 04afc452b3
1 changed files with 112 additions and 0 deletions
@@ -0,0 +1,112 @@
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from unittest import mock
+
+from nova.scheduler import weights
+from nova.tests.functional import integrated_helpers
+
+
+class HostNameWeigher(weights.BaseHostWeigher):
+    # We want to predictabilly have host1 first
+    _weights = {'host1': 1, 'host2': 0}
+
+    def _weigh_object(self, host_state, weight_properties):
+        # Any undefined host gets no weight.
+        return self._weights.get(host_state.host, 0)
+
+
+class TestImagePropsWeigher(integrated_helpers._IntegratedTestBase):
+    """Tests for image props weigher """
+
+    compute_driver = 'fake.MediumFakeDriver'
+    microversion = 'latest'
+    ADMIN_API = True
+
+    def _setup_compute_service(self):
+        # Override to prevent the default 'compute' service from starting
+        pass
+
+    def setUp(self):
+        weight_classes = [
+            __name__ + '.HostNameWeigher',
+            'nova.scheduler.weights.image_props.ImagePropertiesWeigher'
+        ]
+        self.flags(weight_classes=weight_classes,
+                   group='filter_scheduler')
+        self.flags(image_props_weight_multiplier=2.0, group='filter_scheduler')
+        super(TestImagePropsWeigher, self).setUp()
+
+        # Start only the compute services we want for testing
+        self.compute1 = self._start_compute('host1')
+        self.compute2 = self._start_compute('host2')
+
+    @mock.patch('nova.weights.LOG.debug')
+    def test_boot(self, mock_debug):
+        server1 = self._create_server(
+            name='inst1',
+            networks='none',
+            )
+
+        # the weigher sees that there are no existing instances on both hosts
+        # with the same image props
+        mock_debug.assert_any_call(
+            "%s: raw weights %s",
+            "ImagePropertiesWeigher",
+            {('host2', 'host2'): 0.0, ('host1', 'host1'): 0.0})
+        # because of the HostNameWeigher, we're sure that the instance lands
+        # on host1
+        self.assertEqual('host1', server1['OS-EXT-SRV-ATTR:host'])
+        # let's make sure that we don't assert the calls from the previous
+        # schedules.
+        mock_debug.reset_mock()
+
+        server2 = self._create_server(
+            name='inst2',
+            host='host2',
+            networks='none',
+            )
+        # Since we force to a host, the weigher will not be called
+        self.assertEqual('host2', server2['OS-EXT-SRV-ATTR:host'])
+
+        server3 = self._create_server(
+            name='inst3',
+            networks='none',
+            )
+
+        # The weigher is called but it says that there are no existing
+        # instances on both the hosts with the same image props, while we are
+        # sure that the values should be 1.0 for both hosts.
+        # FIXME(sbauza): That's due to bug/2125935
+        mock_debug.assert_any_call(
+            "%s: raw weights %s",
+            "ImagePropertiesWeigher",
+            {('host2', 'host2'): 0.0, ('host1', 'host1'): 0.0})
+        mock_debug.reset_mock()
+        # server3 is now on the same host than host1 as the weigh multiplier
+        # makes the scheduler to pack instances sharing the same image props.
+        self.assertEqual('host1', server3['OS-EXT-SRV-ATTR:host'])
+
+        server4 = self._create_server(
+            name='inst4',
+            networks='none',
+            )
+        # FIXME(sbauza): Same issue. The values should be 2.0 for host1 and 1.0
+        # for host2. That said, due to the fact the HostState is refreshed
+        # already for the previous schedule, the system metadata is existing
+        # for this instance so that's why the weight is 1.0 for host1.
+        mock_debug.assert_any_call(
+            "%s: raw weights %s",
+            "ImagePropertiesWeigher",
+            {('host2', 'host2'): 0.0, ('host1', 'host1'): 1.0})
+        # server4 is now packed with server1 and server3.
+        self.assertEqual('host1', server4['OS-EXT-SRV-ATTR:host'])