Use Instance Objects for Start/Stop

This patch makes the start and stop operations use the Instance
object instead of passing SQLA-derived dicts over RPC. Until
something more sophisticated is needed (and developed), it also
adds a nova.object.register_all() function which just triggers
imports of all the object models so that they are registered.
When adding a new object type, that register function should be
updated appropriately.

Related to bp/unified-object-model

Change-Id: I3c8d9cba07d34097a279502062906de802d19d1f

2 files changed, 28 insertions, 7 deletions

diff --git a/nova/api/ec2/cloud.py b/nova/api/ec2/cloud.py
index da0a52caa..af50868d7 100644
--- a/nova/api/ec2/cloud.py
+++ b/nova/api/ec2/cloud.py
@@ -43,6 +43,7 @@ from nova import exception
 from nova.image import s3
 from nova import network
 from nova.network.security_group import quantum_driver
+from nova.objects import instance as instance_obj
 from nova.openstack.common import log as logging
 from nova.openstack.common import timeutils
 from nova import quota
@@ -206,6 +207,16 @@ def _format_mappings(properties, result):
         result['blockDeviceMapping'] = mappings
 
 
+def db_to_inst_obj(context, db_instance):
+    # NOTE(danms): This is a temporary helper method for converting
+    # Instance DB objects to NovaObjects without needing to re-query.
+    inst_obj = instance_obj.Instance._from_db_object(
+        instance_obj.Instance(), db_instance,
+        expected_attrs=['system_metadata', 'metadata'])
+    inst_obj._context = context
+    return inst_obj
+
+
 class CloudController(object):
     """CloudController provides the critical dispatch between
  inbound API calls through the endpoint and messages
@@ -1340,13 +1351,18 @@ class CloudController(object):
             block_device_mapping=kwargs.get('block_device_mapping', {}))
         return self._format_run_instances(context, resv_id)
 
-    def _ec2_ids_to_instances(self, context, instance_id):
+    def _ec2_ids_to_instances(self, context, instance_id, objects=False):
         """Get all instances first, to prevent partial executions."""
         instances = []
+        extra = ['system_metadata', 'metadata']
         for ec2_id in instance_id:
             validate_ec2_id(ec2_id)
             instance_uuid = ec2utils.ec2_inst_id_to_uuid(context, ec2_id)
-            instance = self.compute_api.get(context, instance_uuid)
+            if objects:
+                instance = instance_obj.Instance.get_by_uuid(
+                    context, instance_uuid, expected_attrs=extra)
+            else:
+                instance = self.compute_api.get(context, instance_uuid)
             instances.append(instance)
         return instances
 
@@ -1372,7 +1388,7 @@ class CloudController(object):
     def stop_instances(self, context, instance_id, **kwargs):
         """Stop each instances in instance_id.
         Here instance_id is a list of instance ids"""
-        instances = self._ec2_ids_to_instances(context, instance_id)
+        instances = self._ec2_ids_to_instances(context, instance_id, True)
         LOG.debug(_("Going to stop instances"))
         for instance in instances:
             self.compute_api.stop(context, instance)
@@ -1381,7 +1397,7 @@ class CloudController(object):
     def start_instances(self, context, instance_id, **kwargs):
         """Start each instances in instance_id.
         Here instance_id is a list of instance ids"""
-        instances = self._ec2_ids_to_instances(context, instance_id)
+        instances = self._ec2_ids_to_instances(context, instance_id, True)
         LOG.debug(_("Going to start instances"))
         for instance in instances:
             self.compute_api.start(context, instance)
@@ -1635,7 +1651,8 @@ class CloudController(object):
 
             if vm_state == vm_states.ACTIVE:
                 restart_instance = True
-                self.compute_api.stop(context, instance)
+                inst_obj = db_to_inst_obj(context, instance)
+                self.compute_api.stop(context, inst_obj)
 
             # wait instance for really stopped
             start_time = time.time()
@@ -1677,7 +1694,8 @@ class CloudController(object):
         ec2_id = ec2utils.glance_id_to_ec2_id(context, new_image['id'])
 
         if restart_instance:
-            self.compute_api.start(context, instance)
+            inst_obj = db_to_inst_obj(context, instance)
+            self.compute_api.start(context, inst_obj)
 
         return {'imageId': ec2_id}
 
diff --git a/nova/api/openstack/compute/contrib/server_start_stop.py b/nova/api/openstack/compute/contrib/server_start_stop.py
index c4d0d5c9e..2803cd04b 100644
--- a/nova/api/openstack/compute/contrib/server_start_stop.py
+++ b/nova/api/openstack/compute/contrib/server_start_stop.py
@@ -20,6 +20,7 @@ from nova.api.openstack import extensions
 from nova.api.openstack import wsgi
 from nova import compute
 from nova import exception
+from nova.objects import instance as instance_obj
 from nova.openstack.common import log as logging
 
 
@@ -33,7 +34,9 @@ class ServerStartStopActionController(wsgi.Controller):
 
     def _get_instance(self, context, instance_uuid):
         try:
-            return self.compute_api.get(context, instance_uuid)
+            attrs = ['system_metadata', 'metadata']
+            return instance_obj.Instance.get_by_uuid(context, instance_uuid,
+                                                     expected_attrs=attrs)
         except exception.NotFound:
             msg = _("Instance not found")
             raise webob.exc.HTTPNotFound(explanation=msg)