Add cache-mode test for volume-backed live migration

Implements: RHELOSP-27741
Change-Id: Id954525b7a18b29aabf1a35cd73d56a8f70d52c8

whitebox_tempest_plugin/api/compute/test_live_migration.py

@@ -0,0 +1,123 @@
+# Copyright 2019 Red Hat, Inc.
+# Copyright 2012 OpenStack Foundation
+# 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.
+
+from oslo_log import log as logging
+import testtools
+import xml.etree.ElementTree as ET
+
+from tempest.common import utils
+from tempest.common import waiters
+from tempest import config
+from tempest.lib import decorators
+
+from whitebox_tempest_plugin.api.compute import base
+from whitebox_tempest_plugin.common import utils as whitebox_utils
+from whitebox_tempest_plugin.services import clients
+
+CONF = config.CONF
+LOG = logging.getLogger(__name__)
+
+# NOTE(mdbooth): This test was originally based on
+#   tempest.api.compute.admin.test_live_migration
+
+
+class LiveMigrationTest(base.BaseTest):
+    # First support for block_migration='auto': since Mitaka (OSP9)
+    min_microversion = '2.25'
+
+    @classmethod
+    def skip_checks(cls):
+        super(LiveMigrationTest, cls).skip_checks()
+
+        if not CONF.compute_feature_enabled.live_migration:
+            skip_msg = ("%s skipped as live-migration is "
+                        "not available" % cls.__name__)
+            raise cls.skipException(skip_msg)
+        if CONF.compute.min_compute_nodes < 2:
+            raise cls.skipException(
+                "Less than 2 compute nodes, skipping migration test.")
+
+    @classmethod
+    def setup_credentials(cls):
+        # These tests don't attempt any SSH validation nor do they use
+        # floating IPs on the instance, so all we need is a network and
+        # a subnet so the instance being migrated has a single port, but
+        # we need that to make sure we are properly updating the port
+        # host bindings during the live migration.
+        # TODO(mriedem): SSH validation before and after the instance is
+        # live migrated would be a nice test wrinkle addition.
+        cls.set_network_resources(network=True, subnet=True)
+        super(LiveMigrationTest, cls).setup_credentials()
+
+    @classmethod
+    def setup_clients(cls):
+        super(LiveMigrationTest, cls).setup_clients()
+        cls.admin_migration_client = cls.os_admin.migrations_client
+
+    def _live_migrate(self, server_id, target_host, state):
+        self.admin_servers_client.live_migrate_server(
+            server_id, host=target_host, block_migration='auto')
+        waiters.wait_for_server_status(self.servers_client, server_id, state)
+        migration_list = (self.admin_migration_client.list_migrations()
+                          ['migrations'])
+
+        msg = ("Live Migration failed. Migrations list for Instance "
+               "%s: [" % server_id)
+        for live_migration in migration_list:
+            if (live_migration['instance_uuid'] == server_id):
+                msg += "\n%s" % live_migration
+        msg += "]"
+        self.assertEqual(target_host, self.get_host_for_server(server_id),
+                         msg)
+
+    def _get_server_libvirt_domain(self, server_id):
+        compute_node_address = whitebox_utils.get_hypervisor_ip(
+            self.servers_client, server_id)
+
+        LOG.debug("Connecting to hypervisor %s for server %s",
+                  compute_node_address, server_id)
+
+        virshxml = clients.VirshXMLClient(compute_node_address)
+        xml = virshxml.dumpxml(server_id)
+        return ET.fromstring(xml)
+
+    @testtools.skipUnless(CONF.compute_feature_enabled.
+                          volume_backed_live_migration,
+                          'Volume-backed live migration not available')
+    @decorators.idempotent_id('41e92884-ed04-42da-89fc-ef8922646542')
+    @utils.services('volume')
+    def test_volume_backed_live_migration(self):
+        # Live migrate an instance to another host
+        server_id = self.create_test_server(wait_until="ACTIVE",
+                                            volume_backed=True)['id']
+
+        def root_disk_cache():
+            domain = self._get_server_libvirt_domain(server_id)
+            return domain.find(
+                "devices/disk/target[@dev='vda']/../driver").attrib['cache']
+
+        # The initial value of disk cache depends on config and the storage in
+        # use. We can't guess it, so fetch it before we start.
+        cache_type = root_disk_cache()
+
+        source_host = self.get_host_for_server(server_id)
+        destination_host = self.get_host_other_than(server_id)
+        LOG.info("Live migrate from source %s to destination %s",
+                 source_host, destination_host)
+        self._live_migrate(server_id, destination_host, 'ACTIVE')
+
+        # Assert cache-mode has not changed during live migration
+        self.assertEqual(cache_type, root_disk_cache())