Send a full instance via rpc for post_live_migration_at_destination.

Change the post_live_migration_at_destination method of the compute
rpc API to take a full instance over rpc instead of just
the instance UUID.  This cuts down on database access needed
by nova-compute.

The method got moved in rpcapi.py, but that was just to restore
alphabetical order.

Part of blueprint no-db-messaging.

Change-Id: Ib36cb065f838f644e97b6e82b39409737df15558

2 files changed, 23 insertions, 19 deletions

diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index ae47b6caa..7e555b010 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -298,7 +298,7 @@ def _get_additional_capabilities():
 class ComputeManager(manager.SchedulerDependentManager):
     """Manages the running instances from creation to destruction."""
 
-    RPC_API_VERSION = '1.19'
+    RPC_API_VERSION = '1.20'
 
     def __init__(self, compute_driver=None, *args, **kwargs):
         """Load configuration options and connect to the hypervisor."""
@@ -2338,7 +2338,8 @@ class ComputeManager(manager.SchedulerDependentManager):
                    "This error can be safely ignored."),
                  instance=instance_ref)
 
-    def post_live_migration_at_destination(self, context, instance_id,
+    def post_live_migration_at_destination(self, context, instance=None,
+                                           instance_id=None,
                                            block_migration=False):
         """Post operations for live migration .
 
@@ -2347,34 +2348,33 @@ class ComputeManager(manager.SchedulerDependentManager):
         :param block_migration: if true, prepare for block migration
 
         """
-        instance_ref = self.db.instance_get(context, instance_id)
+        if not instance:
+            instance = self.db.instance_get(context, instance_id)
         LOG.info(_('Post operation of migraton started'),
-                 instance=instance_ref)
+                 instance=instance)
 
         # NOTE(tr3buchet): setup networks on destination host
         #                  this is called a second time because
         #                  multi_host does not create the bridge in
         #                  plug_vifs
-        self.network_api.setup_networks_on_host(context, instance_ref,
+        self.network_api.setup_networks_on_host(context, instance,
                                                          self.host)
 
-        network_info = self._get_instance_nw_info(context, instance_ref)
-        self.driver.post_live_migration_at_destination(context, instance_ref,
+        network_info = self._get_instance_nw_info(context, instance)
+        self.driver.post_live_migration_at_destination(context, instance,
                                             self._legacy_nw_info(network_info),
                                             block_migration)
         # Restore instance state
-        current_power_state = self._get_power_state(context, instance_ref)
+        current_power_state = self._get_power_state(context, instance)
         self._instance_update(context,
-                              instance_ref['uuid'],
+                              instance['uuid'],
                               host=self.host,
                               power_state=current_power_state,
                               vm_state=vm_states.ACTIVE,
                               task_state=None)
 
         # NOTE(vish): this is necessary to update dhcp
-        self.network_api.setup_networks_on_host(context,
-                                                instance_ref,
-                                                self.host)
+        self.network_api.setup_networks_on_host(context, instance, self.host)
 
     def rollback_live_migration(self, context, instance_ref,
                                 dest, block_migration):
diff --git a/nova/compute/rpcapi.py b/nova/compute/rpcapi.py
index 4b012de78..7243e37c5 100644
--- a/nova/compute/rpcapi.py
+++ b/nova/compute/rpcapi.py
@@ -82,6 +82,8 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
         1.18 - Remove instance_uuid, add instance argument to inject_file()
         1.19 - Remove instance_uuid, add instance argument to
                inject_network_info()
+        1.20 - Remove instance_id, add instance argument to
+               post_live_migration_at_destination()
     '''
 
     BASE_RPC_API_VERSION = '1.0'
@@ -232,13 +234,6 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                 topic=_compute_topic(self.topic, ctxt, None, instance),
                 version='1.19')
 
-    def post_live_migration_at_destination(self, ctxt, instance,
-            block_migration, host):
-        return self.call(ctxt,
-                self.make_msg('post_live_migration_at_destination',
-                instance_id=instance['id'], block_migration=block_migration),
-                _compute_topic(self.topic, ctxt, host, None))
-
     def pause_instance(self, ctxt, instance):
         instance_p = jsonutils.to_primitive(instance)
         self.cast(ctxt, self.make_msg('pause_instance',
@@ -246,6 +241,15 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                 topic=_compute_topic(self.topic, ctxt, None, instance),
                 version='1.5')
 
+    def post_live_migration_at_destination(self, ctxt, instance,
+            block_migration, host):
+        instance_p = jsonutils.to_primitive(instance)
+        return self.call(ctxt,
+                self.make_msg('post_live_migration_at_destination',
+                instance=instance_p, block_migration=block_migration),
+                _compute_topic(self.topic, ctxt, host, None),
+                version='1.20')
+
     def power_off_instance(self, ctxt, instance):
         self.cast(ctxt, self.make_msg('power_off_instance',
                 instance_uuid=instance['uuid']),