Add new API to force live migration to complete

This change adds manual knob to force ongoing live migration to
complete. It is implemented as a new server-migrations API.

DocImpact
ApiImpact

Implements: blueprint pause-vm-during-live-migration
Change-Id: I034b4041414a797f65ede52db2963107f2ef7456

doc/api_samples/server-migrations/force_complete.json

@@ -0,0 +1,3 @@
+{
+    "force_complete": null
+}

doc/api_samples/server-migrations/live-migrate-server.json

@@ -0,0 +1,7 @@
+{
+    "os-migrateLive": {
+        "host": "01c0cadef72d47e28a672a76060d492c",
+        "block_migration": false,
+        "disk_over_commit": false
+    }
+}

doc/api_samples/versions/v21-version-get-resp.json

@@ -19,7 +19,7 @@
             }
         ],
         "status": "CURRENT",
-        "version": "2.21",
+        "version": "2.22",
         "min_version": "2.1",
         "updated": "2013-07-23T11:33:21Z"
     }

doc/api_samples/versions/versions-get-resp.json

@@ -22,7 +22,7 @@
                 }
             ],
             "status": "CURRENT",
-            "version": "2.21",
+            "version": "2.22",
             "min_version": "2.1",
             "updated": "2013-07-23T11:33:21Z"
         }

doc/notification_samples/service-update.json

@@ -13,7 +13,7 @@
             "disabled_reason": null,
             "report_count": 1,
             "forced_down": false,
-            "version": 6
+            "version": 7
         }
     },
     "event_type": "service.update",

etc/nova/policy.json

@@ -270,6 +270,8 @@
     "os_compute_api:servers:start": "rule:admin_or_owner",
     "os_compute_api:servers:stop": "rule:admin_or_owner",
     "os_compute_api:servers:trigger_crash_dump": "rule:admin_or_owner",
+    "os_compute_api:servers:migrations:discoverable": "",
+    "os_compute_api:servers:migrations:force_complete": "rule:admin_api",
     "os_compute_api:os-access-ips:discoverable": "",
     "os_compute_api:os-access-ips": "",
     "os_compute_api:os-admin-actions": "rule:admin_api",

nova/api/openstack/api_version_request.py

@@ -64,7 +64,7 @@ REST_API_VERSION_HISTORY = """REST API Version History:
     * 2.20 - Add attach and detach volume operations for instances in shelved
              and shelved_offloaded state
     * 2.21 - Make os-instance-actions read deleted instances
-
+    * 2.22 - Add API to force live migration to complete
 """
 
 # The minimum and maximum versions of the API supported
@@ -73,7 +73,7 @@ REST_API_VERSION_HISTORY = """REST API Version History:
 # Note(cyeoh): This only applies for the v2.1 API once microversions
 # support is fully merged. It does not affect the V2 API.
 _MIN_API_VERSION = "2.1"
-_MAX_API_VERSION = "2.21"
+_MAX_API_VERSION = "2.22"
 DEFAULT_API_VERSION = _MIN_API_VERSION
 
 

nova/api/openstack/compute/extension_info.py

@@ -82,7 +82,7 @@ v21_to_v2_extension_list_mapping = {
 v2_extension_suppress_list = ['servers', 'images', 'versions', 'flavors',
                               'os-block-device-mapping-v1', 'os-consoles',
                               'extensions', 'image-metadata', 'ips', 'limits',
-                              'server-metadata'
+                              'server-metadata', 'server-migrations'
                             ]
 
 # v2.1 plugins which should appear under a different name in v2

nova/api/openstack/compute/schemas/server_migrations.py

@@ -0,0 +1,26 @@
+# Copyright 2016 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.
+
+
+force_complete = {
+    'type': 'object',
+    'properties': {
+        'force_complete': {
+            'type': 'null'
+        }
+    },
+    'required': ['force_complete'],
+    'additionalProperties': False,
+}

nova/api/openstack/compute/server_migrations.py

@@ -0,0 +1,78 @@
+# Copyright 2016 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 webob import exc
+
+from nova.api.openstack import common
+from nova.api.openstack.compute.schemas import server_migrations
+from nova.api.openstack import extensions
+from nova.api.openstack import wsgi
+from nova.api import validation
+from nova import compute
+from nova import exception
+
+ALIAS = 'servers:migrations'
+authorize = extensions.os_compute_authorizer(ALIAS)
+
+
+class ServerMigrationsController(wsgi.Controller):
+    """The server migrations API controller for the OpenStack API."""
+
+    def __init__(self):
+        self.compute_api = compute.API(skip_policy_check=True)
+        super(ServerMigrationsController, self).__init__()
+
+    @wsgi.Controller.api_version("2.22")
+    @wsgi.response(202)
+    @extensions.expected_errors((400, 403, 404, 409))
+    @wsgi.action('force_complete')
+    @validation.schema(server_migrations.force_complete)
+    def _force_complete(self, req, id, server_id, body):
+        context = req.environ['nova.context']
+        authorize(context, action='force_complete')
+
+        instance = common.get_instance(self.compute_api, context, server_id)
+        try:
+            self.compute_api.live_migrate_force_complete(context, instance, id)
+        except exception.InstanceNotFound as e:
+            raise exc.HTTPNotFound(explanation=e.format_message())
+        except (exception.MigrationNotFoundByStatus,
+                exception.InvalidMigrationState,
+                exception.MigrationNotFoundForInstance) as e:
+            raise exc.HTTPBadRequest(explanation=e.format_message())
+        except exception.InstanceIsLocked as e:
+            raise exc.HTTPConflict(explanation=e.format_message())
+        except exception.InstanceInvalidState as state_error:
+            common.raise_http_conflict_for_instance_invalid_state(
+                state_error, 'force_complete', server_id)
+
+
+class ServerMigrations(extensions.V21APIExtensionBase):
+    """Server Migrations API."""
+    name = "ServerMigrations"
+    alias = 'server-migrations'
+    version = 1
+
+    def get_resources(self):
+        parent = {'member_name': 'server',
+                  'collection_name': 'servers'}
+        member_actions = {'action': 'POST'}
+        resources = [extensions.ResourceExtension(
+            'migrations', ServerMigrationsController(),
+            parent=parent, member_actions=member_actions)]
+        return resources
+
+    def get_controller_extensions(self):
+        return []

nova/api/openstack/rest_api_version_history.rst

@@ -181,5 +181,17 @@ user documentation.
 
 2.21
 ----
+
   The ``os-instance-actions`` API now returns information from deleted
   instances.
+
+2.22
+----
+
+  A new resource servers:migrations added. A new API to force live migration
+  to complete added::
+
+    POST /servers/<uuid>/migrations/<id>/action
+    {
+      "force_complete": null
+    }

nova/compute/api.py

@@ -3287,6 +3287,35 @@ class API(base.Base):
                 host_name, block_migration=block_migration,
                 disk_over_commit=disk_over_commit)
 
+    @check_instance_lock
+    @check_instance_cell
+    @check_instance_state(vm_state=[vm_states.ACTIVE],
+                          task_state=[task_states.MIGRATING])
+    def live_migrate_force_complete(self, context, instance, migration_id):
+        """Force live migration to complete.
+
+        :param context: Security context
+        :param instance: The instance that is being migrated
+        :param migration_id: ID of ongoing migration
+
+        """
+        LOG.debug("Going to try to force live migration to complete",
+                  instance=instance)
+
+        # NOTE(pkoniszewski): Get migration object to check if there is ongoing
+        # live migration for particular instance. Also pass migration id to
+        # compute to double check and avoid possible race condition.
+        migration = objects.Migration.get_by_id_and_instance(
+            context, migration_id, instance.uuid)
+        if migration.status != 'running':
+            raise exception.InvalidMigrationState(migration_id=migration_id,
+                                                  instance_uuid=instance.uuid,
+                                                  state=migration.status,
+                                                  method='force complete')
+
+        self.compute_rpcapi.live_migration_force_complete(
+            context, instance, migration.id)
+
     @check_instance_state(vm_state=[vm_states.ACTIVE, vm_states.STOPPED,
                                     vm_states.ERROR])
     def evacuate(self, context, instance, host, on_shared_storage,

nova/compute/manager.py

@@ -671,7 +671,7 @@ class ComputeVirtAPI(virtapi.VirtAPI):
 class ComputeManager(manager.Manager):
     """Manages the running instances from creation to destruction."""
 
-    target = messaging.Target(version='4.8')
+    target = messaging.Target(version='4.9')
 
     # How long to wait in seconds before re-issuing a shutdown
     # signal to an instance during power off.  The overall
@@ -5250,6 +5250,29 @@ class ComputeManager(manager.Manager):
                       block_migration, migration,
                       migrate_data)
 
+    @wrap_exception()
+    @wrap_instance_fault
+    def live_migration_force_complete(self, context, instance, migration_id):
+        """Force live migration to complete.
+
+        :param context: Security context
+        :param instance: The instance that is being migrated
+        :param migration_id: ID of ongoing migration
+
+        """
+        migration = objects.Migration.get_by_id(context, migration_id)
+        if migration.status != 'running':
+            raise exception.InvalidMigrationState(migration_id=migration_id,
+                                                  instance_uuid=instance.uuid,
+                                                  state=migration.status,
+                                                  method='force complete')
+
+        self._notify_about_instance_usage(
+            context, instance, 'live.migration.force.complete.start')
+        self.driver.live_migration_force_complete(instance)
+        self._notify_about_instance_usage(
+            context, instance, 'live.migration.force.complete.end')
+
     def _live_migration_cleanup_flags(self, block_migration, migrate_data):
         """Determine whether disks or instance path need to be cleaned up after
         live migration (at source on success, at destination on rollback)

nova/compute/rpcapi.py

@@ -325,6 +325,7 @@ class ComputeAPI(object):
                  rollback_live_migration_at_destination, and
                  pre_live_migration.
         * ...  - Remove refresh_provider_fw_rules()
+        * 4.9  - Add live_migration_force_complete()
     '''
 
     VERSION_ALIASES = {
@@ -636,6 +637,13 @@ class ComputeAPI(object):
                    dest=dest, block_migration=block_migration,
                    migrate_data=migrate_data, **args)
 
+    def live_migration_force_complete(self, ctxt, instance, migration_id):
+        version = '4.9'
+        cctxt = self.client.prepare(server=_compute_host(None, instance),
+                version=version)
+        cctxt.cast(ctxt, 'live_migration_force_complete', instance=instance,
+                   migration_id=migration_id)
+
     def pause_instance(self, ctxt, instance):
         version = '4.0'
         cctxt = self.client.prepare(server=_compute_host(None, instance),

nova/exception.py

@@ -1127,6 +1127,12 @@ class MigrationNotFoundForInstance(MigrationNotFound):
                 "%(instance_id)s")
 
 
+class InvalidMigrationState(Invalid):
+    msg_fmt = _("Migration %(migration_id)s state of instance "
+                "%(instance_uuid)s is %(state)s. Cannot %(method)s while the "
+                "migration is in this state.")
+
+
 class ConsoleLogOutputException(NovaException):
     msg_fmt = _("Console log output could not be retrieved for instance "
                 "%(instance_id)s. Reason: %(reason)s")

nova/objects/service.py

@@ -29,7 +29,7 @@ LOG = logging.getLogger(__name__)
 
 
 # NOTE(danms): This is the global service version counter
-SERVICE_VERSION = 6
+SERVICE_VERSION = 7
 
 
 # NOTE(danms): This is our SERVICE_VERSION history. The idea is that any
@@ -65,6 +65,8 @@ SERVICE_VERSION_HISTORY = (
     {'compute_rpc': '4.7'},
     # Version 6: Compute RPC version 4.8
     {'compute_rpc': '4.8'},
+    # Version 7: Add live_migration_force_complete in the compute_rpc
+    {'compute_rpc': '4.9'},
 )
 
 

nova/tests/functional/api_sample_tests/api_samples/server-migrations/force_complete.json.tpl

@@ -0,0 +1,3 @@
+{
+    "force_complete": null
+}

nova/tests/functional/api_sample_tests/api_samples/server-migrations/live-migrate-server.json.tpl

@@ -0,0 +1,7 @@
+{
+    "os-migrateLive": {
+        "host": "%(hostname)s",
+        "block_migration": false,
+        "disk_over_commit": false
+    }
+}

nova/tests/functional/api_sample_tests/test_server_migrations.py

@@ -0,0 +1,52 @@
+# Copyright 2016 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.
+
+import mock
+
+from nova.conductor import manager as conductor_manager
+from nova import db
+from nova import objects
+from nova.tests.functional.api_sample_tests import test_servers
+
+
+class ServerMigrationsSampleJsonTest(test_servers.ServersSampleBase):
+    extension_name = 'server-migrations'
+    scenarios = [('v2_22', {'api_major_version': 'v2.1'})]
+    extra_extensions_to_load = ["os-migrate-server", "os-access-ips"]
+
+    def setUp(self):
+        """setUp method for server usage."""
+        super(ServerMigrationsSampleJsonTest, self).setUp()
+        self.uuid = self._post_server()
+
+    @mock.patch.object(conductor_manager.ComputeTaskManager, '_live_migrate')
+    @mock.patch.object(db, 'service_get_by_compute_host')
+    @mock.patch.object(objects.Migration, 'get_by_id_and_instance')
+    @mock.patch('nova.compute.manager.ComputeManager.'
+                'live_migration_force_complete')
+    def test_live_migrate_force_complete(self, live_migration_pause_instance,
+                                         get_by_id_and_instance,
+                                         service_get_by_compute_host,
+                                         _live_migrate):
+        migration = objects.Migration()
+        migration.id = 1
+        migration.status = 'running'
+        get_by_id_and_instance.return_value = migration
+        self._do_post('servers/%s/action' % self.uuid, 'live-migrate-server',
+                      {'hostname': self.compute.host})
+        response = self._do_post('servers/%s/migrations/%s/action'
+                                 % (self.uuid, '3'), 'force_complete',
+                                 {}, api_version='2.22')
+        self.assertEqual(202, response.status_code)

nova/tests/unit/api/openstack/compute/test_server_migrations.py

@@ -0,0 +1,108 @@
+# Copyright 2016 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.
+
+import mock
+import webob
+
+from nova.api.openstack.compute import server_migrations
+from nova import exception
+from nova import test
+from nova.tests.unit.api.openstack import fakes
+
+
+class ServerMigrationsTestsV21(test.NoDBTestCase):
+    wsgi_api_version = '2.22'
+
+    def setUp(self):
+        super(ServerMigrationsTestsV21, self).setUp()
+        self.req = fakes.HTTPRequest.blank('', version=self.wsgi_api_version)
+        self.context = self.req.environ['nova.context']
+        self.controller = server_migrations.ServerMigrationsController()
+        self.compute_api = self.controller.compute_api
+
+    def test_force_complete_succeeded(self):
+        @mock.patch.object(self.compute_api, 'live_migrate_force_complete')
+        @mock.patch.object(self.compute_api, 'get')
+        def _do_test(compute_api_get, live_migrate_force_complete):
+            self.controller._force_complete(self.req, '1', '1',
+                                            body={'force_complete': None})
+            live_migrate_force_complete.assert_called_once_with(
+                self.context, compute_api_get(), '1')
+        _do_test()
+
+    def _test_force_complete_failed_with_exception(self, fake_exc,
+                                                   expected_exc):
+        @mock.patch.object(self.compute_api, 'live_migrate_force_complete',
+                           side_effect=fake_exc)
+        @mock.patch.object(self.compute_api, 'get')
+        def _do_test(compute_api_get, live_migrate_force_complete):
+            self.assertRaises(expected_exc,
+                              self.controller._force_complete,
+                              self.req, '1', '1',
+                              body={'force_complete': None})
+        _do_test()
+
+    def test_force_complete_instance_not_migrating(self):
+        self._test_force_complete_failed_with_exception(
+            exception.InstanceInvalidState(instance_uuid='', state='',
+                                           attr='', method=''),
+            webob.exc.HTTPConflict)
+
+    def test_force_complete_migration_not_found(self):
+        self._test_force_complete_failed_with_exception(
+            exception.MigrationNotFoundByStatus(instance_id='', status=''),
+            webob.exc.HTTPBadRequest)
+
+    def test_force_complete_instance_is_locked(self):
+        self._test_force_complete_failed_with_exception(
+            exception.InstanceIsLocked(instance_uuid=''),
+            webob.exc.HTTPConflict)
+
+    def test_force_complete_invalid_migration_state(self):
+        self._test_force_complete_failed_with_exception(
+            exception.InvalidMigrationState(migration_id='', instance_uuid='',
+                                            state='', method=''),
+            webob.exc.HTTPBadRequest)
+
+    def test_force_complete_instance_not_found(self):
+        self._test_force_complete_failed_with_exception(
+            exception.InstanceNotFound(instance_id=''),
+            webob.exc.HTTPNotFound)
+
+    def test_force_complete_unexpected_error(self):
+            self._test_force_complete_failed_with_exception(
+                exception.NovaException(), webob.exc.HTTPInternalServerError)
+
+
+class ServerMigrationsPolicyEnforcementV21(test.NoDBTestCase):
+    wsgi_api_version = '2.22'
+
+    def setUp(self):
+        super(ServerMigrationsPolicyEnforcementV21, self).setUp()
+        self.controller = server_migrations.ServerMigrationsController()
+        self.req = fakes.HTTPRequest.blank('', version=self.wsgi_api_version)
+
+    def test_migrate_live_policy_failed(self):
+        rule_name = "os_compute_api:servers:migrations:force_complete"
+        self.policy.set_rules({rule_name: "project:non_fake"})
+        body_args = {'force_complete': None}
+        exc = self.assertRaises(
+                                exception.PolicyNotAuthorized,
+                                self.controller._force_complete, self.req,
+                                fakes.FAKE_UUID, fakes.FAKE_UUID,
+                                body=body_args)
+        self.assertEqual(
+                      "Policy doesn't allow %s to be performed." % rule_name,
+                      exc.format_message())

nova/tests/unit/compute/test_compute_api.py

@@ -3212,6 +3212,55 @@ class _ComputeAPIUnitTestMixIn(object):
             self.assertEqual(expect_statuses[instance.uuid],
                              host_statuses[instance.uuid])
 
+    @mock.patch.object(objects.Migration, 'get_by_id_and_instance')
+    def test_live_migrate_force_complete_succeeded(
+            self, get_by_id_and_instance):
+
+        if self.cell_type == 'api':
+            # cell api has not been implemented.
+            return
+        rpcapi = self.compute_api.compute_rpcapi
+
+        instance = self._create_instance_obj()
+        instance.task_state = task_states.MIGRATING
+
+        migration = objects.Migration()
+        migration.id = 0
+        migration.status = 'running'
+        get_by_id_and_instance.return_value = migration
+
+        with mock.patch.object(
+                rpcapi, 'live_migration_force_complete') as lm_force_complete:
+            self.compute_api.live_migrate_force_complete(
+                self.context, instance, migration.id)
+
+            lm_force_complete.assert_called_once_with(self.context,
+                                                      instance,
+                                                      0)
+
+    @mock.patch.object(objects.Migration, 'get_by_id_and_instance')
+    def test_live_migrate_force_complete_invalid_migration_state(
+            self, get_by_id_and_instance):
+        instance = self._create_instance_obj()
+        instance.task_state = task_states.MIGRATING
+
+        migration = objects.Migration()
+        migration.id = 0
+        migration.status = 'error'
+        get_by_id_and_instance.return_value = migration
+
+        self.assertRaises(exception.InvalidMigrationState,
+                          self.compute_api.live_migrate_force_complete,
+                          self.context, instance, migration.id)
+
+    def test_live_migrate_force_complete_invalid_vm_state(self):
+        instance = self._create_instance_obj()
+        instance.task_state = None
+
+        self.assertRaises(exception.InstanceInvalidState,
+                          self.compute_api.live_migrate_force_complete,
+                          self.context, instance, '1')
+
 
 class ComputeAPIUnitTestCase(_ComputeAPIUnitTestMixIn, test.NoDBTestCase):
     def setUp(self):

nova/tests/unit/compute/test_compute_mgr.py

@@ -4356,3 +4356,50 @@ class ComputeManagerMigrationTestCase(test.NoDBTestCase):
                                                   'foo', False, {})
             self.assertIsInstance(mock_lmcf.call_args_list[0][0][1],
                                   migrate_data_obj.LiveMigrateData)
+
+    def test_live_migration_force_complete_succeeded(self):
+
+        instance = objects.Instance(uuid=str(uuid.uuid4()))
+        migration = objects.Migration()
+        migration.status = 'running'
+        migration.id = 0
+
+        @mock.patch.object(self.compute, '_notify_about_instance_usage')
+        @mock.patch.object(objects.Migration, 'get_by_id',
+                           return_value=migration)
+        @mock.patch.object(self.compute.driver,
+                           'live_migration_force_complete')
+        def _do_test(force_complete, get_by_id, _notify_about_instance_usage):
+            self.compute.live_migration_force_complete(
+                self.context, instance, migration.id)
+
+            force_complete.assert_called_once_with(instance)
+
+            _notify_usage_calls = [
+                mock.call(self.context, instance,
+                          'live.migration.force.complete.start'),
+                mock.call(self.context, instance,
+                          'live.migration.force.complete.end')
+            ]
+
+            _notify_about_instance_usage.assert_has_calls(_notify_usage_calls)
+
+        _do_test()
+
+    @mock.patch.object(compute_utils, 'add_instance_fault_from_exc')
+    def test_live_migration_pause_vm_invalid_migration_state(
+            self, add_instance_fault_from_exc):
+
+        instance = objects.Instance(id=1234, uuid=str(uuid.uuid4()))
+        migration = objects.Migration()
+        migration.status = 'aborted'
+        migration.id = 0
+
+        @mock.patch.object(objects.Migration, 'get_by_id',
+                           return_value=migration)
+        def _do_test(get_by_id):
+            self.assertRaises(exception.InvalidMigrationState,
+                              self.compute.live_migration_force_complete,
+                              self.context, instance, migration.id)
+
+        _do_test()

nova/tests/unit/compute/test_rpcapi.py

@@ -304,6 +304,11 @@ class ComputeRpcAPITestCase(test.NoDBTestCase):
                 migration='migration',
                 migrate_data={}, version='4.8')
 
+    def test_live_migration_force_complete(self):
+        self._test_compute_api('live_migration_force_complete', 'cast',
+                instance=self.fake_instance_obj,
+                migration_id='1', version='4.9')
+
     def test_post_live_migration_at_destination(self):
         self._test_compute_api('post_live_migration_at_destination', 'cast',
                 instance=self.fake_instance_obj,

nova/tests/unit/fake_policy.py

@@ -125,6 +125,7 @@ policy_data = """
     "os_compute_api:servers:start": "",
     "os_compute_api:servers:stop": "",
     "os_compute_api:servers:trigger_crash_dump": "",
+    "os_compute_api:servers:migrations:force_complete": "",
     "os_compute_api:os-access-ips": "",
     "compute_extension:accounts": "",
     "compute_extension:admin_actions:pause": "",

nova/tests/unit/test_policy.py

@@ -300,6 +300,7 @@ class RealRolePolicyTestCase(test.NoDBTestCase):
 "os_compute_api:servers:detail:get_all_tenants",
 "os_compute_api:servers:index:get_all_tenants",
 "os_compute_api:servers:show:host_status",
+"os_compute_api:servers:migrations:force_complete",
 "network:attach_external_network",
 "os_compute_api:os-admin-actions",
 "os_compute_api:os-admin-actions:reset_network",
@@ -672,6 +673,7 @@ class RealRolePolicyTestCase(test.NoDBTestCase):
 "os_compute_api:os-server-usage:discoverable",
 "os_compute_api:os-server-groups",
 "os_compute_api:os-server-groups:discoverable",
+"os_compute_api:servers:migrations:discoverable",
 "os_compute_api:os-services:discoverable",
 "os_compute_api:server-metadata:discoverable",
 "os_compute_api:servers:discoverable",

nova/tests/unit/virt/libvirt/test_driver.py

@@ -13015,6 +13015,12 @@ class LibvirtConnTestCase(test.NoDBTestCase):
                           lambda x: x,
                           lambda x: x)
 
+    @mock.patch.object(libvirt_driver.LibvirtDriver, "pause")
+    def test_live_migration_force_complete(self, pause):
+        drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
+        drvr.live_migration_force_complete(self.test_instance)
+        pause.assert_called_once_with(self.test_instance)
+
     @mock.patch('os.path.exists', return_value=True)
     @mock.patch('tempfile.mkstemp')
     @mock.patch('os.close', return_value=None)

nova/tests/unit/virt/test_virt_drivers.py

@@ -661,6 +661,11 @@ class _VirtDriverTestCase(_FakeDriverBackendTestCase):
         self.connection.live_migration(self.ctxt, instance_ref, 'otherhost',
                                        lambda *a: None, lambda *a: None)
 
+    @catch_notimplementederror
+    def test_live_migration_force_complete(self):
+        instance_ref, network_info = self._get_running_instance()
+        self.connection.live_migration_force_complete(instance_ref)
+
     @catch_notimplementederror
     def _check_available_resource_fields(self, host_status):
         keys = ['vcpus', 'memory_mb', 'local_gb', 'vcpus_used',

nova/virt/driver.py

@@ -860,6 +860,14 @@ class ComputeDriver(object):
         """
         raise NotImplementedError()
 
+    def live_migration_force_complete(self, instance):
+        """Force live migration to complete
+
+        :param instance: Instance being live migrated
+
+        """
+        raise NotImplementedError()
+
     def rollback_live_migration_at_destination(self, context, instance,
                                                network_info,
                                                block_device_info,

nova/virt/fake.py

@@ -468,6 +468,9 @@ class FakeDriver(driver.ComputeDriver):
                             migrate_data)
         return
 
+    def live_migration_force_complete(self, instance):
+        return
+
     def check_can_live_migrate_destination_cleanup(self, context,
                                                    dest_check_data):
         return

nova/virt/libvirt/driver.py

@@ -6413,6 +6413,12 @@ class LibvirtDriver(driver.ComputeDriver):
             LOG.debug("Live migration monitoring is all done",
                       instance=instance)
 
+    def live_migration_force_complete(self, instance):
+        # NOTE(pkoniszewski): currently only pause during live migration is
+        # supported to force live migration to complete, so just try to pause
+        # the instance
+        self.pause(instance)
+
     def _try_fetch_image(self, context, path, image_id, instance,
                          fallback_from_host=None):
         try:

releasenotes/notes/force-live-migration-be5a10cd9c8eb981.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - A new REST API to force live migration to complete has been added
+    in microversion 2.22.

setup.cfg

@@ -137,6 +137,7 @@ nova.api.v21.extensions =
     server_diagnostics = nova.api.openstack.compute.server_diagnostics:ServerDiagnostics
     server_external_events = nova.api.openstack.compute.server_external_events:ServerExternalEvents
     server_metadata = nova.api.openstack.compute.server_metadata:ServerMetadata
+    server_migrations = nova.api.openstack.compute.server_migrations:ServerMigrations
     server_password = nova.api.openstack.compute.server_password:ServerPassword
     server_usage = nova.api.openstack.compute.server_usage:ServerUsage
     server_groups = nova.api.openstack.compute.server_groups:ServerGroups