Send a full instance via rpc for (un)pause_instance.

Change the pause_instance and unpause_instance methods 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: Ia7e31428c7d2edb9a0c4d0958f1c7774742ea1cd

2 files changed, 25 insertions, 17 deletions

diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index cced8509b..9ebfe496b 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -297,7 +297,7 @@ def _get_additional_capabilities():
 class ComputeManager(manager.SchedulerDependentManager):
     """Manages the running instances from creation to destruction."""
 
-    RPC_API_VERSION = '1.4'
+    RPC_API_VERSION = '1.5'
 
     def __init__(self, compute_driver=None, *args, **kwargs):
         """Load configuration options and connect to the hypervisor."""
@@ -1713,17 +1713,18 @@ class ComputeManager(manager.SchedulerDependentManager):
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @checks_instance_lock
     @wrap_instance_fault
-    def pause_instance(self, context, instance_uuid):
+    def pause_instance(self, context, instance=None, instance_uuid=None):
         """Pause an instance on this host."""
         context = context.elevated()
-        instance_ref = self.db.instance_get_by_uuid(context, instance_uuid)
+        if not instance:
+            instance = self.db.instance_get_by_uuid(context, instance_uuid)
 
-        LOG.audit(_('Pausing'), context=context, instance=instance_ref)
-        self.driver.pause(instance_ref)
+        LOG.audit(_('Pausing'), context=context, instance=instance)
+        self.driver.pause(instance)
 
-        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'],
                               power_state=current_power_state,
                               vm_state=vm_states.PAUSED,
                               task_state=None)
@@ -1731,17 +1732,18 @@ class ComputeManager(manager.SchedulerDependentManager):
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @checks_instance_lock
     @wrap_instance_fault
-    def unpause_instance(self, context, instance_uuid):
+    def unpause_instance(self, context, instance=None, instance_uuid=None):
         """Unpause a paused instance on this host."""
         context = context.elevated()
-        instance_ref = self.db.instance_get_by_uuid(context, instance_uuid)
+        if not instance:
+            instance = self.db.instance_get_by_uuid(context, instance_uuid)
 
-        LOG.audit(_('Unpausing'), context=context, instance=instance_ref)
-        self.driver.unpause(instance_ref)
+        LOG.audit(_('Unpausing'), context=context, instance=instance)
+        self.driver.unpause(instance)
 
-        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'],
                               power_state=current_power_state,
                               vm_state=vm_states.ACTIVE,
                               task_state=None)
diff --git a/nova/compute/rpcapi.py b/nova/compute/rpcapi.py
index e480ee20d..d5de04452 100644
--- a/nova/compute/rpcapi.py
+++ b/nova/compute/rpcapi.py
@@ -60,6 +60,8 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
         1.2 - Adds check_can_live_migrate_[destination|source]
         1.3 - Adds change_instance_metadata()
         1.4 - Remove instance_uuid, add instance argument to reboot_instance()
+        1.5 - Remove instance_uuid, add instance argument to pause_instance(),
+              unpause_instance()
     '''
 
     BASE_RPC_API_VERSION = '1.0'
@@ -211,9 +213,11 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                 _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',
-                instance_uuid=instance['uuid']),
-                topic=_compute_topic(self.topic, ctxt, None, instance))
+                instance=instance_p),
+                topic=_compute_topic(self.topic, ctxt, None, instance),
+                version='1.5')
 
     def power_off_instance(self, ctxt, instance):
         self.cast(ctxt, self.make_msg('power_off_instance',
@@ -361,9 +365,11 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                 topic=_compute_topic(self.topic, ctxt, None, instance))
 
     def unpause_instance(self, ctxt, instance):
+        instance_p = jsonutils.to_primitive(instance)
         self.cast(ctxt, self.make_msg('unpause_instance',
-                instance_uuid=instance['uuid']),
-                topic=_compute_topic(self.topic, ctxt, None, instance))
+                instance=instance_p),
+                topic=_compute_topic(self.topic, ctxt, None, instance),
+                version='1.5')
 
     def unrescue_instance(self, ctxt, instance):
         self.cast(ctxt, self.make_msg('unrescue_instance',