Don't send unuseful rpc alarm notification

If the alarm have no actions for the new state we don't need to send a
message through the rpc for notification, just log a debug message
when it occur.

Fixes bug 1224416

Change-Id: I9aeb01e936dbacfbabb06e8b408d5ee04a93cb34

ceilometer/alarm/rpc.py

@@ -20,6 +20,8 @@ from oslo.config import cfg
 
 from ceilometer.openstack.common import context
 from ceilometer.openstack.common.rpc import proxy as rpc_proxy
+from ceilometer.openstack.common import log
+from ceilometer.openstack.common.gettextutils import _
 from ceilometer.storage.models import Alarm
 
 OPTS = [
@@ -34,6 +36,8 @@ OPTS = [
 
 cfg.CONF.register_opts(OPTS, group='alarm')
 
+LOG = log.getLogger(__name__)
+
 
 class RPCAlarmNotifier(rpc_proxy.RpcProxy):
     def __init__(self):
@@ -43,6 +47,14 @@ class RPCAlarmNotifier(rpc_proxy.RpcProxy):
 
     def notify(self, alarm, previous, reason):
         actions = getattr(alarm, Alarm.ALARM_ACTIONS_MAP[alarm.state])
+        if not actions:
+            LOG.debug(_('alarm %(alarm_id)s has no action configured '
+                        'for state transition from %(previous)s to '
+                        'state %(state)s, skipping the notification.') %
+                      {'alarm_id': alarm.alarm_id,
+                       'previous': previous,
+                       'state': alarm.state})
+            return
         msg = self.make_msg('notify_alarm', data={
             'actions': actions,
             'alarm_id': alarm.alarm_id,

tests/alarm/test_rpc.py

@@ -96,3 +96,23 @@ class TestRPCAlarmNotifier(base.TestCase):
         self.notifier.notify(self.alarms[0], 'ok', 42)
         reason = self.notified[0][1]['args']['data']['reason']
         self.assertTrue(isinstance(reason, basestring))
+
+    def test_notify_no_actions(self):
+        alarm = AlarmClient(None, info={
+            'name': 'instance_running_hot',
+            'meter_name': 'cpu_util',
+            'comparison_operator': 'gt',
+            'threshold': 80.0,
+            'evaluation_periods': 5,
+            'statistic': 'avg',
+            'state': 'ok',
+            'user_id': 'foobar',
+            'project_id': 'snafu',
+            'period': 60,
+            'ok_actions': [],
+            'alarm_id': str(uuid.uuid4()),
+            'matching_metadata': {'resource_id':
+                                  'my_instance'}
+        })
+        self.notifier.notify(alarm, 'alarm', "what?")
+        self.assertEqual(len(self.notified), 0)