Merge "Add functional recreate test for regression bug 1825537" into stable/stein

Author: Zuul

nova/tests/functional/regressions/test_bug_1825537.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 nova.tests.functional import integrated_helpers
+
+
+class FinishResizeErrorAllocationCleanupTestCase(
+        integrated_helpers.ProviderUsageBaseTestCase):
+    """Test for bug 1825537 introduced in Rocky and backported down to Pike.
+
+    Tests a scenario where finish_resize fails on the dest compute during a
+    resize and ensures resource provider allocations are properly cleaned up
+    in placement.
+    """
+
+    compute_driver = 'fake.FakeFinishMigrationFailDriver'
+
+    def setUp(self):
+        super(FinishResizeErrorAllocationCleanupTestCase, self).setUp()
+        # Get the flavors we're going to use.
+        flavors = self.api.get_flavors()
+        self.flavor1 = flavors[0]
+        self.flavor2 = flavors[1]
+
+    def _resize_and_assert_error(self, server, dest_host):
+        # Now resize the server and wait for it to go to ERROR status because
+        # the finish_migration virt driver method in host2 should fail.
+        req = {'resize': {'flavorRef': self.flavor2['id']}}
+        self.api.post_server_action(server['id'], req)
+        # The instance is set to ERROR status before the fault is recorded so
+        # to avoid a race we need to wait for the task_state to change
+        # to None which happens after the fault is recorded.
+        server = self._wait_for_server_parameter(
+            self.admin_api, server,
+            {'status': 'ERROR', 'OS-EXT-STS:task_state': None})
+        # The server should be pointing at $dest_host because resize_instance
+        # will have updated the host/node value on the instance before casting
+        # to the finish_resize method on the dest compute.
+        self.assertEqual(dest_host, server['OS-EXT-SRV-ATTR:host'])
+        # In this case the FakeFinishMigrationFailDriver.finish_migration
+        # method raises VirtualInterfaceCreateException.
+        self.assertIn('Virtual Interface creation failed',
+                      server['fault']['message'])
+
+    def test_finish_resize_fails_allocation_cleanup(self):
+        # Start two computes so we can resize across hosts.
+        self._start_compute('host1')
+        self._start_compute('host2')
+
+        # Create a server on host1.
+        server = self._boot_and_check_allocations(self.flavor1, 'host1')
+
+        # Resize to host2 which should fail.
+        self._resize_and_assert_error(server, 'host2')
+
+        # Check the resource provider allocations. Since the server is pointed
+        # at the dest host in the DB now, the dest node resource provider
+        # allocations should still exist with the new flavor.
+        source_rp_uuid = self._get_provider_uuid_by_host('host1')
+        dest_rp_uuid = self._get_provider_uuid_by_host('host2')
+        # FIXME(mriedem): This is bug 1825537 where the allocations are
+        # reverted when finish_resize fails so the dest node resource provider
+        # does not have any allocations and the instance allocations are for
+        # the old flavor on the source node resource provider even though the
+        # instance is not running on the source host nor pointed at the source
+        # host in the DB.
+        # self.assertFlavorMatchesAllocation(
+        #     self.flavor2, server['id'], dest_rp_uuid)
+        dest_rp_usages = self._get_provider_usages(dest_rp_uuid)
+        no_usage = {'VCPU': 0, 'MEMORY_MB': 0, 'DISK_GB': 0}
+        self.assertEqual(no_usage, dest_rp_usages)
+        self.assertFlavorMatchesAllocation(
+            self.flavor1, server['id'], source_rp_uuid)

nova/tests/functional/test_servers.py

@@ -3723,6 +3723,7 @@ def fake_resize_method(*args, **kwargs):
 
         # Ensure the allocation records still exist on the host.
         source_rp_uuid = self._get_provider_uuid_by_host(hostname)
+        # FIXME(mriedem): This is wrong for the _finish_resize case.
         # The new_flavor should have been subtracted from the doubled
         # allocation which just leaves us with the original flavor.
         self.assertFlavorMatchesUsage(source_rp_uuid, self.flavor1)

nova/virt/fake.py

@@ -731,6 +731,13 @@ def update_provider_tree(self, provider_tree, nodename, allocations=None):
                                        self.child_resources)
 
 
+class FakeFinishMigrationFailDriver(FakeDriver):
+    """FakeDriver variant that will raise an exception from finish_migration"""
+
+    def finish_migration(self, *args, **kwargs):
+        raise exception.VirtualInterfaceCreateException()
+
+
 class FakeRescheduleDriver(FakeDriver):
     """FakeDriver derivative that triggers a reschedule on the first spawn
     attempt. This is expected to only be used in tests that have more than