Add a regression test for bug 1939545

Assert the behaviour of the libvirt driver during pre_live_migration
with instances that have block based volumes attached.

Bug #1939545 covering the case where the returned path from os-brick
isn't being saved into the connection_info of the associated bdm in
Nova.

The cinder fixture is extended as part of this change to offer
connection_info listing the iscsi volume type in order to correctly
assert the behaviour of the associated libvirt volume driver.

Related-Bug: #1939545
Change-Id: I3f1073d70e4332737e33f3c9c00cf129d0ef76b4

1 files changed, 110 insertions, 0 deletions

diff --git a/nova/tests/functional/regressions/test_bug_1939545.py b/nova/tests/functional/regressions/test_bug_1939545.py
new file mode 100644
index 0000000000..1c0827cf54
--- /dev/null
+++ b/nova/tests/functional/regressions/test_bug_1939545.py
@@ -0,0 +1,110 @@
+# Copyright 2021, Red Hat, Inc. All Rights Reserved.
+#
+# 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.
+
+import fixtures
+import mock
+
+from oslo_serialization import jsonutils
+
+from nova import context
+from nova import objects
+from nova.tests import fixtures as nova_fixtures
+from nova.tests.fixtures import libvirt as fakelibvirt
+from nova.tests.functional import integrated_helpers
+from nova.tests.functional.libvirt import base
+
+
+class TestLiveMigrateUpdateDevicePath(
+    base.ServersTestBase,
+    integrated_helpers.InstanceHelperMixin
+):
+    """Regression test for bug 1939545
+
+    Assert the behaviour of the libvirt driver during pre_live_migration with
+    instances that have block based volumes attached.
+
+    Bug #1939545 covering the case where the returned path from os-brick
+    isn't being saved into the connection_info of the associated bdm in Nova.
+    """
+
+    api_major_version = 'v2.1'
+    microversion = 'latest'
+    ADMIN_API = True
+
+    def setUp(self):
+        super().setUp()
+
+        # TODO(lyarwood): Move into base.ServersTestBase
+        self.useFixture(nova_fixtures.OSBrickFixture())
+
+        # TODO(lyarwood): Move into base.ServersTestBase to allow live
+        # migrations to pass without changes by the test classes.
+        self.useFixture(fixtures.MonkeyPatch(
+            'nova.tests.fixtures.libvirt.Domain.migrateToURI3',
+            self._migrate_stub))
+
+        self.start_compute(
+            hostname='src',
+            host_info=fakelibvirt.HostInfo(
+                cpu_nodes=1, cpu_sockets=1, cpu_cores=4, cpu_threads=1))
+        self.start_compute(
+            hostname='dest',
+            host_info=fakelibvirt.HostInfo(
+                cpu_nodes=1, cpu_sockets=1, cpu_cores=4, cpu_threads=1))
+
+    def _migrate_stub(self, domain, destination, params, flags):
+        dest = self.computes['dest']
+        dest.driver._host.get_connection().createXML(
+            params['destination_xml'],
+            'fake-createXML-doesnt-care-about-flags')
+        source = self.computes['src']
+        conn = source.driver._host.get_connection()
+        dom = conn.lookupByUUIDString(self.server['id'])
+        dom.complete_job()
+
+    # TODO(lyarwood): Move this into the os-brick fixture and repeat for all
+    # provided connectors at runtime.
+    @mock.patch(
+        'os_brick.initiator.connectors.iscsi.ISCSIConnector.connect_volume')
+    @mock.patch(
+        'os_brick.initiator.connectors.iscsi.ISCSIConnector.disconnect_volume')
+    def test_live_migrate_update_device_path(
+        self, mock_disconnect_volume, mock_connect_volume
+    ):
+        self.server = self._create_server(host='src', networks='none')
+        volume_id = self.cinder.ISCSI_BACKED_VOL
+
+        # TODO(lyarwood): As above, move this into the os-brick fixture.
+        mock_connect_volume.return_value = {'path': '/dev/sda'}
+
+        self.api.post_server_volume(
+            self.server['id'], {'volumeAttachment': {'volumeId': volume_id}})
+
+        # Get the volume bdm and assert that the connection_info is set with
+        # device_path from the volume driver.
+        ctxt = context.get_admin_context()
+        bdm = objects.BlockDeviceMapping.get_by_volume_and_instance(
+            ctxt, volume_id, self.server['id'])
+        connection_info = jsonutils.loads(bdm.connection_info)
+        self.assertIn('device_path', connection_info.get('data'))
+
+        # Live migrate the instance to another host
+        self._live_migrate(self.server)
+
+        # FIXME(lyarwood): This is bug #1939545, again get the volume bdm and
+        # assert that the saved connection_info doesn't contain device_path.
+        bdm = objects.BlockDeviceMapping.get_by_volume_and_instance(
+            ctxt, volume_id, self.server['id'])
+        connection_info = jsonutils.loads(bdm.connection_info)
+        self.assertNotIn('device_path', connection_info.get('data'))