Add confirm_snapshot_based_resize conductor RPC method

This adds the conductor ComputeTaskManager method
confirm_snapshot_based_resize along with the related conductor
RPC API client method which by default will be an RPC cast
from the API for a confirmResize server action but can also
be RPC called in the case of deleting a server in VERIFY_RESIZE
status.

Part of blueprint cross-cell-resize

Change-Id: If4c4b23891bfc340deb18a2f500510a472a869c9

Author: mriedem

nova/conductor/api.py

@@ -175,3 +175,8 @@ def cache_images(self, context, aggregate, image_ids):
             self.image_api.get(context, image_id)
         self.conductor_compute_rpcapi.cache_images(context, aggregate,
                                                    image_ids)
+
+    def confirm_snapshot_based_resize(
+            self, ctxt, instance, migration, do_cast=True):
+        self.conductor_compute_rpcapi.confirm_snapshot_based_resize(
+            ctxt, instance, migration, do_cast=do_cast)

nova/conductor/manager.py

@@ -38,6 +38,7 @@
 from nova.compute import utils as compute_utils
 from nova.compute.utils import wrap_instance_event
 from nova.compute import vm_states
+from nova.conductor.tasks import cross_cell_migrate
 from nova.conductor.tasks import live_migrate
 from nova.conductor.tasks import migrate
 from nova import context as nova_context
@@ -232,7 +233,7 @@ class ComputeTaskManager(base.Base):
     may involve coordinating activities on multiple compute nodes.
     """
 
-    target = messaging.Target(namespace='compute_task', version='1.21')
+    target = messaging.Target(namespace='compute_task', version='1.22')
 
     def __init__(self):
         super(ComputeTaskManager, self).__init__()
@@ -1859,3 +1860,18 @@ def skipped_host(context, host, image_ids):
             context, aggregate,
             fields.NotificationAction.IMAGE_CACHE,
             fields.NotificationPhase.END)
+
+    @targets_cell
+    @wrap_instance_event(prefix='conductor')
+    def confirm_snapshot_based_resize(self, context, instance, migration):
+        """Executes the ConfirmResizeTask
+
+        :param context: nova auth request context targeted at the target cell
+        :param instance: Instance object in "resized" status from the target
+            cell
+        :param migration: Migration object from the target cell for the resize
+            operation expected to have status "confirming"
+        """
+        task = cross_cell_migrate.ConfirmResizeTask(
+            context, instance, migration, self.notifier, self.compute_rpcapi)
+        task.execute()

nova/conductor/rpcapi.py

@@ -21,6 +21,7 @@
 
 import nova.conf
 from nova import exception
+from nova.i18n import _
 from nova.objects import base as objects_base
 from nova import profiler
 from nova import rpc
@@ -283,6 +284,7 @@ class ComputeTaskAPI(object):
     1.20 - migrate_server() now gets a 'host_list' parameter that represents
            potential alternate hosts for retries within a cell.
     1.21 - Added cache_images()
+    1.22 - Added confirm_snapshot_based_resize()
     """
 
     def __init__(self):
@@ -452,3 +454,14 @@ def cache_images(self, ctxt, aggregate, image_ids):
         cctxt = self.client.prepare(version=version)
         cctxt.cast(ctxt, 'cache_images', aggregate=aggregate,
                    image_ids=image_ids)
+
+    def confirm_snapshot_based_resize(
+            self, ctxt, instance, migration, do_cast=True):
+        version = '1.22'
+        if not self.client.can_send_version(version):
+            raise exception.ServiceTooOld(_('nova-conductor too old'))
+        kw = {'instance': instance, 'migration': migration}
+        cctxt = self.client.prepare(version=version)
+        if do_cast:
+            return cctxt.cast(ctxt, 'confirm_snapshot_based_resize', **kw)
+        return cctxt.call(ctxt, 'confirm_snapshot_based_resize', **kw)

nova/tests/unit/conductor/test_conductor.py

@@ -1771,6 +1771,18 @@ def test_evacuate_instance_with_request_spec(self, mock_notify):
             self.context, inst_obj, 'thebesthost', action='rebuild_scheduled',
             source='nova-conductor')
 
+    @mock.patch(
+        'nova.conductor.tasks.cross_cell_migrate.ConfirmResizeTask.execute')
+    def test_confirm_snapshot_based_resize(self, mock_execute):
+        instance = self._create_fake_instance_obj(ctxt=self.context)
+        migration = objects.Migration(
+            context=self.context, source_compute=instance.host,
+            source_node=instance.node, instance_uuid=instance.uuid,
+            status='confirming', migration_type='resize')
+        self.conductor_manager.confirm_snapshot_based_resize(
+            self.context, instance=instance, migration=migration)
+        mock_execute.assert_called_once_with()
+
 
 class ConductorTaskTestCase(_BaseTaskTestCase, test_compute.BaseTestCase):
     """ComputeTaskManager Tests."""
@@ -3794,6 +3806,43 @@ def _test(prepare_mock, can_send_mock):
 
         _test()
 
+    def _test_confirm_snapshot_based_resize(self, do_cast):
+        """Tests how confirm_snapshot_based_resize is called when do_cast is
+        True or False.
+        """
+        instance = objects.Instance()
+        migration = objects.Migration()
+
+        @mock.patch.object(self.conductor.client, 'can_send_version',
+                           return_value=True)
+        @mock.patch.object(self.conductor.client, 'prepare')
+        def _test(prepare_mock, can_send_mock):
+            self.conductor.confirm_snapshot_based_resize(
+                self.context, instance, migration, do_cast=do_cast)
+            kw = {'instance': instance, 'migration': migration}
+            if do_cast:
+                prepare_mock.return_value.cast.assert_called_once_with(
+                    self.context, 'confirm_snapshot_based_resize', **kw)
+            else:
+                prepare_mock.return_value.call.assert_called_once_with(
+                    self.context, 'confirm_snapshot_based_resize', **kw)
+        _test()
+
+    def test_confirm_snapshot_based_resize_cast(self):
+        self._test_confirm_snapshot_based_resize(do_cast=True)
+
+    def test_confirm_snapshot_based_resize_call(self):
+        self._test_confirm_snapshot_based_resize(do_cast=False)
+
+    def test_confirm_snapshot_based_resize_old_service(self):
+        """Tests confirm_snapshot_based_resize when the service is too old."""
+        with mock.patch.object(
+                self.conductor.client, 'can_send_version', return_value=False):
+            self.assertRaises(exc.ServiceTooOld,
+                              self.conductor.confirm_snapshot_based_resize,
+                              self.context, mock.sentinel.instance,
+                              mock.sentinel.migration)
+
 
 class ConductorTaskAPITestCase(_BaseTaskTestCase, test_compute.BaseTestCase):
     """Compute task API Tests."""