Send a full instance in rescue_instance.

Change the rescue_instance 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.

Part of blueprint no-db-messaging.

Change-Id: I559bd45a8dda4537f6f4a3b8d744095291c7f058

2 files changed, 24 insertions, 15 deletions

diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index e23db6812..09c82035f 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -272,7 +272,7 @@ def _get_image_meta(context, image_ref):
 class ComputeManager(manager.SchedulerDependentManager):
     """Manages the running instances from creation to destruction."""
 
-    RPC_API_VERSION = '1.26'
+    RPC_API_VERSION = '1.27'
 
     def __init__(self, compute_driver=None, *args, **kwargs):
         """Load configuration options and connect to the hypervisor."""
@@ -1320,28 +1320,33 @@ class ComputeManager(manager.SchedulerDependentManager):
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @checks_instance_lock
     @wrap_instance_fault
-    def rescue_instance(self, context, instance_uuid, **kwargs):
+    def rescue_instance(self, context, instance=None, instance_uuid=None,
+                        rescue_password=None):
         """
         Rescue an instance on this host.
         :param rescue_password: password to set on rescue instance
         """
-
-        LOG.audit(_('Rescuing'), context=context, instance_uuid=instance_uuid)
         context = context.elevated()
+        if not instance:
+            instance = self.db.instance_get_by_uuid(context, instance_uuid)
 
-        instance_ref = self.db.instance_get_by_uuid(context, instance_uuid)
-        instance_ref.admin_pass = kwargs.get('rescue_password',
-                utils.generate_password(FLAGS.password_length))
-        network_info = self._get_instance_nw_info(context, instance_ref)
-        image_meta = _get_image_meta(context, instance_ref['image_ref'])
+        LOG.audit(_('Rescuing'), context=context, instance=instance)
 
-        with self.error_out_instance_on_exception(context, instance_uuid):
-            self.driver.rescue(context, instance_ref,
+        admin_pass = (rescue_password if rescue_password else
+                      utils.generate_password(FLAGS.password_length))
+        self.db.instance_update(context, instance['uuid'],
+                                dict(admin_pass=admin_pass))
+
+        network_info = self._get_instance_nw_info(context, instance)
+        image_meta = _get_image_meta(context, instance['image_ref'])
+
+        with self.error_out_instance_on_exception(context, instance['uuid']):
+            self.driver.rescue(context, instance,
                                self._legacy_nw_info(network_info), image_meta)
 
-        current_power_state = self._get_power_state(context, instance_ref)
+        current_power_state = self._get_power_state(context, instance)
         self._instance_update(context,
-                              instance_uuid,
+                              instance['uuid'],
                               vm_state=vm_states.RESCUED,
                               task_state=None,
                               power_state=current_power_state)
diff --git a/nova/compute/rpcapi.py b/nova/compute/rpcapi.py
index d7cc3e2b9..d79cb0bba 100644
--- a/nova/compute/rpcapi.py
+++ b/nova/compute/rpcapi.py
@@ -96,6 +96,8 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                remove_fixed_ip_from_instance()
         1.26 - Remove instance_id, add instance argument to
                remove_volume_connection()
+        1.27 - Remove instance_uuid, add instance argument to
+               rescue_instance()
     '''
 
     BASE_RPC_API_VERSION = '1.0'
@@ -344,10 +346,12 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                 version='1.26')
 
     def rescue_instance(self, ctxt, instance, rescue_password):
+        instance_p = jsonutils.to_primitive(instance)
         self.cast(ctxt, self.make_msg('rescue_instance',
-                instance_uuid=instance['uuid'],
+                instance=instance_p,
                 rescue_password=rescue_password),
-                topic=_compute_topic(self.topic, ctxt, None, instance))
+                topic=_compute_topic(self.topic, ctxt, None, instance),
+                version='1.27')
 
     def reset_network(self, ctxt, instance):
         self.cast(ctxt, self.make_msg('reset_network',