Send a full instance via rpc for get_diagnostics.

Change the get_diagnostics 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: Ic4db237849230899ad5f2f0780d4c237895a6631

3 files changed, 14 insertions, 10 deletions

diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index d744a069b..aeebc577a 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 = '1.15'
+    RPC_API_VERSION = '1.16'
 
     def __init__(self, compute_driver=None, *args, **kwargs):
         """Load configuration options and connect to the hypervisor."""
@@ -1777,14 +1777,15 @@ class ComputeManager(manager.SchedulerDependentManager):
 
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @wrap_instance_fault
-    def get_diagnostics(self, context, instance_uuid):
+    def get_diagnostics(self, context, instance_uuid=None, instance=None):
         """Retrieve diagnostics for an instance on this host."""
-        instance_ref = self.db.instance_get_by_uuid(context, instance_uuid)
-        current_power_state = self._get_power_state(context, instance_ref)
+        if not instance:
+            instance = self.db.instance_get_by_uuid(context, instance_uuid)
+        current_power_state = self._get_power_state(context, instance)
         if current_power_state == power_state.RUNNING:
             LOG.audit(_("Retrieving diagnostics"), context=context,
-                      instance=instance_ref)
-            return self.driver.get_diagnostics(instance_ref)
+                      instance=instance)
+            return self.driver.get_diagnostics(instance)
 
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @checks_instance_lock
diff --git a/nova/compute/rpcapi.py b/nova/compute/rpcapi.py
index 35db1fe72..95f7f0d23 100644
--- a/nova/compute/rpcapi.py
+++ b/nova/compute/rpcapi.py
@@ -77,6 +77,7 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
         1.14 - Remove instance_uuid, add instance argument to finish_resize()
         1.15 - Remove instance_uuid, add instance argument to
                finish_revert_resize()
+        1.16 - Remove instance_uuid, add instance argument to get_diagnostics()
     '''
 
     BASE_RPC_API_VERSION = '1.0'
@@ -181,9 +182,11 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                 topic=_compute_topic(self.topic, ctxt, host, None))
 
     def get_diagnostics(self, ctxt, instance):
+        instance_p = jsonutils.to_primitive(instance)
         return self.call(ctxt, self.make_msg('get_diagnostics',
-                instance_uuid=instance['uuid']),
-                topic=_compute_topic(self.topic, ctxt, None, instance))
+                instance=instance_p),
+                topic=_compute_topic(self.topic, ctxt, None, instance),
+                version='1.16')
 
     def get_instance_disk_info(self, ctxt, instance):
         return self.call(ctxt, self.make_msg('get_instance_disk_info',
diff --git a/nova/tests/compute/test_rpcapi.py b/nova/tests/compute/test_rpcapi.py
index 427acf949..bec10009c 100644
--- a/nova/tests/compute/test_rpcapi.py
+++ b/nova/tests/compute/test_rpcapi.py
@@ -53,7 +53,7 @@ class ComputeRpcAPITestCase(test.TestCase):
             'check_can_live_migrate_destination',
             'check_can_live_migrate_source', 'confirm_resize',
             'detach_volume', 'finish_resize', 'finish_revert_resize',
-            'get_console_output',
+            'get_console_output', 'get_diagnostics',
             'pause_instance', 'reboot_instance', 'suspend_instance',
             'unpause_instance'
         ]
@@ -183,7 +183,7 @@ class ComputeRpcAPITestCase(test.TestCase):
 
     def test_get_diagnostics(self):
         self._test_compute_api('get_diagnostics', 'call',
-                instance=self.fake_instance)
+                instance=self.fake_instance, version='1.16')
 
     def test_get_instance_disk_info(self):
         self._test_compute_api('get_instance_disk_info', 'call',