Reproduce bug #2025480 in a functional test

Written by gibi, I just cleaned it up.

NOTE(elod.illes): test_bug_2025480.py needed to be edited as
refactoring patch I456f685f480b8de71014cf232a8f08c731605ad8 was only
introduced to Xena and we don't want to backport that.

Change-Id: I8386a846b3685b8d03c59334ccfb2efbd4afe427
Co-Authored-By: Balazs Gibizer <[email protected]>
Related-Bug: #2025480
(cherry picked from commit 62300d4)
(cherry picked from commit 477ff26)
(cherry picked from commit 23c190a)
(cherry picked from commit 7422642)
(cherry picked from commit fc02bdf)
(cherry picked from commit e078152)

nova/tests/functional/regressions/test_bug_2025480.py

@@ -0,0 +1,82 @@
+# 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 import context
+from nova.objects import compute_node
+from nova import test
+from nova.tests import fixtures as nova_fixtures
+from nova.tests.functional import fixtures as func_fixtures
+from nova.tests.functional import integrated_helpers
+from nova.tests.unit import fake_notifier
+
+
+class UnshelveUpdateAvailableResourcesPeriodicRace(
+        test.TestCase, integrated_helpers.InstanceHelperMixin):
+    def setUp(self):
+        super(UnshelveUpdateAvailableResourcesPeriodicRace, self).setUp()
+
+        placement = func_fixtures.PlacementFixture()
+        self.useFixture(placement)
+        self.placement = placement.api
+        self.neutron = nova_fixtures.NeutronFixture(self)
+        self.useFixture(self.neutron)
+        self.useFixture(nova_fixtures.GlanceFixture(self))
+        # Start nova services.
+        self.api = self.useFixture(nova_fixtures.OSAPIFixture(
+            api_version='v2.1')).admin_api
+        self.api.microversion = 'latest'
+        fake_notifier.stub_notifier(self)
+        self.addCleanup(fake_notifier.reset)
+
+        self.start_service('conductor')
+        self.start_service('scheduler')
+
+    def test_unshelve_spawning_update_available_resources(self):
+        compute = self._start_compute('compute1')
+
+        server = self._create_server(
+            networks=[{'port': self.neutron.port_1['id']}])
+
+        node = compute_node.ComputeNode.get_by_nodename(
+            context.get_admin_context(), 'compute1')
+        self.assertEqual(1, node.vcpus_used)
+
+        # with default config shelve means immediate offload as well
+        req = {
+            'shelve': {}
+        }
+        self.api.post_server_action(server['id'], req)
+        self._wait_for_server_parameter(
+            server, {'status': 'SHELVED_OFFLOADED',
+                     'OS-EXT-SRV-ATTR:host': None})
+
+        node = compute_node.ComputeNode.get_by_nodename(
+            context.get_admin_context(), 'compute1')
+        self.assertEqual(0, node.vcpus_used)
+
+        def fake_spawn(*args, **kwargs):
+            self._run_periodics()
+
+        with mock.patch.object(
+                compute.driver, 'spawn', side_effect=fake_spawn):
+            req = {'unshelve': None}
+            self.api.post_server_action(server['id'], req)
+            fake_notifier.wait_for_versioned_notifications(
+                'instance.unshelve.start')
+            self._wait_for_state_change(server, 'ACTIVE')
+
+        node = compute_node.ComputeNode.get_by_nodename(
+            context.get_admin_context(), 'compute1')
+        # This is the bug, the instance should have resources claimed
+        # self.assertEqual(1, node.vcpus_used)
+        self.assertEqual(0, node.vcpus_used)