ceilometer: new Gnocchi Alarm resources

Ceilometer offers two new kind of alarms.
This change adds the associated resources to Heat.

Implements blueprint ceilometer-gnocchi-alarm
Change-Id: I0d3dfcbda7d09361bb90fd16122b903bf4c03fbe

contrib/heat_gnocchi/README.md

@@ -0,0 +1,18 @@
+Gnocchi plugin for OpenStack Heat
+=================================
+
+This plugin adds Ceilometer Gnocchi Alarm resources in a Heat template.
+
+
+### 1. Install the Gnocchi plugin in Heat
+
+NOTE: These instructions assume the value of heat.conf plugin_dirs includes the
+default directory /usr/lib/heat.
+
+To install the plugin, from this directory run:
+    sudo python ./setup.py install
+
+### 2. Restart heat
+
+Only the process "heat-engine" needs to be restarted to load the newly installed
+plugin.

contrib/heat_gnocchi/heat_gnocchi/resources/gnocchi_alarm.py

@@ -0,0 +1,132 @@
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+
+from heat.common.i18n import _
+from heat.engine import constraints
+from heat.engine import properties
+from heat.engine.resources.ceilometer import alarm
+from heat.engine import support
+
+
+COMMON_GNOCCHI_PROPERTIES = (
+    COMPARISON_OPERATOR, EVALUATION_PERIODS, GRANULARITY,
+    AGGREGATION_METHOD, THRESHOLD,
+) = (
+    'comparison_operator', 'evaluation_periods', 'granularity',
+    'aggregation_method', 'threshold',
+)
+
+
+common_gnocchi_properties_schema = {
+    COMPARISON_OPERATOR: properties.Schema(
+        properties.Schema.STRING,
+        _('Operator used to compare specified statistic with threshold.'),
+        constraints=[
+            constraints.AllowedValues(['ge', 'gt', 'eq', 'ne', 'lt',
+                                       'le']),
+        ],
+        update_allowed=True
+    ),
+    EVALUATION_PERIODS: properties.Schema(
+        properties.Schema.INTEGER,
+        _('Number of periods to evaluate over.'),
+        update_allowed=True
+    ),
+    AGGREGATION_METHOD: properties.Schema(
+        properties.Schema.STRING,
+        _('The aggregation method to compare to the threshold'),
+        constraints=[
+            constraints.AllowedValues(['mean', 'sum', 'last', 'max', 'min',
+                                       'std', 'median', 'first', 'count']),
+        ],
+        update_allowed=True
+    ),
+    GRANULARITY: properties.Schema(
+        properties.Schema.INTEGER,
+        _('The time range in seconds.'),
+        update_allowed=True
+    ),
+    THRESHOLD: properties.Schema(
+        properties.Schema.NUMBER,
+        _('Threshold to evaluate against.'),
+        required=True,
+        update_allowed=True
+    ),
+}
+
+
+class CeilometerGnocchiResourcesAlarm(alarm.BaseCeilometerAlarm):
+
+    support_status = support.SupportStatus(version='2015.1')
+
+    PROPERTIES = (
+        METRIC, RESOURCE_CONSTRAINT, RESOURCE_TYPE
+    ) = (
+        'metric', 'resource_constraint', 'resource_type'
+    )
+    PROPERTIES += COMMON_GNOCCHI_PROPERTIES
+
+    properties_schema = {
+        METRIC: properties.Schema(
+            properties.Schema.STRING,
+            _('Metric name watched by the alarm.'),
+            required=True,
+            update_allowed=True
+        ),
+        RESOURCE_CONSTRAINT: properties.Schema(
+            properties.Schema.STRING,
+            _('Id of a resource or expression to select multiple resources'),
+            required=True,
+            update_allowed=True
+        ),
+        RESOURCE_TYPE: properties.Schema(
+            properties.Schema.STRING,
+            _('Resource type'),
+            required=True,
+            update_allowed=True
+        ),
+    }
+    properties_schema.update(common_gnocchi_properties_schema)
+    properties_schema.update(alarm.common_properties_schema)
+
+    ceilometer_alarm_type = 'gnocchi_resources_threshold'
+
+
+class CeilometerGnocchiMetricsAlarm(CeilometerGnocchiResourcesAlarm):
+
+    support_status = support.SupportStatus(version='2015.1')
+
+    PROPERTIES = (METRICS,) = ('metrics',)
+    PROPERTIES += COMMON_GNOCCHI_PROPERTIES
+
+    properties_schema = {
+        METRICS: properties.Schema(
+            properties.Schema.LIST,
+            _('A list of metric ids.'),
+            required=True,
+            update_allowed=True,
+        ),
+    }
+    properties_schema.update(common_gnocchi_properties_schema)
+    properties_schema.update(alarm.common_properties_schema)
+
+    ceilometer_alarm_type = 'gnocchi_metrics_threshold'
+
+
+def resource_mapping():
+    return {
+        'OS::Ceilometer::GnocchiResourcesAlarm':
+            CeilometerGnocchiResourcesAlarm,
+        'OS::Ceilometer::GnocchiMetricslarm': CeilometerGnocchiMetricsAlarm,
+    }

contrib/heat_gnocchi/heat_gnocchi/tests/test_gnocchi_alarm.py

@@ -0,0 +1,366 @@
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import copy
+
+from ceilometerclient import exc as ceilometerclient_exc
+import mock
+import mox
+
+from heat.common import exception
+from heat.common import template_format
+from heat.engine.clients.os import ceilometer
+from heat.engine import resource
+from heat.engine import scheduler
+from heat.tests import common
+from heat.tests import utils
+
+from ..resources import gnocchi_alarm  # noqa
+
+gnocchi_resources_alarm_template = '''
+heat_template_version: 2013-05-23
+description: Gnocchi Resources Alarm Test
+resources:
+  GnoResAlarm:
+    type: OS::Ceilometer::GnocchiResourcesAlarm
+    properties:
+      description: Do stuff with gnocchi
+      metric: cpu_util
+      aggregation_method: mean
+      granularity: 60
+      evaluation_periods: 1
+      threshold: 50
+      alarm_actions: []
+      resource_type: instance
+      resource_constraint: server_group=mystack
+      comparison_operator: gt
+'''
+
+
+gnocchi_metrics_alarm_template = '''
+heat_template_version: 2013-05-23
+description: Gnocchi Metrics Alarm Test
+resources:
+  GnoMetricsAlarm:
+    type: OS::Ceilometer::GnocchiMetricsAlarm
+    properties:
+      description: Do stuff with gnocchi metrics
+      metrics: ["911fce07-e0d7-4210-8c8c-4a9d811fcabc",
+                "2543d435-fe93-4443-9351-fb0156930f94"]
+      aggregation_method: mean
+      granularity: 60
+      evaluation_periods: 1
+      threshold: 50
+      alarm_actions: []
+      comparison_operator: gt
+'''
+
+
+class FakeCeilometerAlarm(object):
+    alarm_id = 'foo'
+
+
+class FakeCeilometerAlarms(object):
+    def create(self, **kwargs):
+        pass
+
+    def update(self, **kwargs):
+        pass
+
+    def delete(self, alarm_id):
+        pass
+
+
+class FakeCeilometerClient(object):
+    alarms = FakeCeilometerAlarms()
+
+
+class GnocchiResourcesAlarmTest(common.HeatTestCase):
+
+    def setUp(self):
+        super(GnocchiResourcesAlarmTest, self).setUp()
+        self.fc = FakeCeilometerClient()
+        resource._register_class("OS::Ceilometer::GnocchiResourcesAlarm",
+                                 gnocchi_alarm.CeilometerGnocchiResourcesAlarm)
+        self.m.StubOutWithMock(ceilometer.CeilometerClientPlugin, '_create')
+
+    def create_alarm(self):
+        ceilometer.CeilometerClientPlugin._create().AndReturn(
+            self.fc)
+        self.m.StubOutWithMock(self.fc.alarms, 'create')
+        self.fc.alarms.create(
+            alarm_actions=[],
+            description=u'Do stuff with gnocchi',
+            enabled=True,
+            insufficient_data_actions=None,
+            ok_actions=None,
+            name=mox.IgnoreArg(), type='gnocchi_resources_threshold',
+            repeat_actions=True,
+            gnocchi_resources_threshold_rule={
+                "metric": "cpu_util",
+                "aggregation_method": "mean",
+                "granularity": 60,
+                "evaluation_periods": 1,
+                "threshold": 50,
+                "resource_type": "instance",
+                "resource_constraint": "server_group=mystack",
+                "comparison_operator": "gt",
+            }
+        ).AndReturn(FakeCeilometerAlarm())
+        snippet = template_format.parse(gnocchi_resources_alarm_template)
+        stack = utils.parse_stack(snippet)
+        resource_defns = stack.t.resource_definitions(stack)
+        return gnocchi_alarm.CeilometerGnocchiResourcesAlarm(
+            'GnoResAlarm', resource_defns['GnoResAlarm'], stack)
+
+    def test_create(self):
+        rsrc = self.create_alarm()
+
+        self.m.ReplayAll()
+        scheduler.TaskRunner(rsrc.create)()
+        self.assertEqual((rsrc.CREATE, rsrc.COMPLETE), rsrc.state)
+        self.assertEqual('foo', rsrc.resource_id)
+        self.m.VerifyAll()
+
+    def test_update(self):
+        rsrc = self.create_alarm()
+        self.m.StubOutWithMock(self.fc.alarms, 'update')
+        self.fc.alarms.update(
+            alarm_id='foo',
+            gnocchi_resources_threshold_rule={
+                'resource_constraint': 'd3d6c642-921e-4fc2-9c5f-15d9a5afb598'})
+
+        self.m.ReplayAll()
+        scheduler.TaskRunner(rsrc.create)()
+
+        update_template = copy.deepcopy(rsrc.t)
+        update_template['Properties']['resource_constraint'] = (
+            'd3d6c642-921e-4fc2-9c5f-15d9a5afb598')
+        scheduler.TaskRunner(rsrc.update, update_template)()
+        self.assertEqual((rsrc.UPDATE, rsrc.COMPLETE), rsrc.state)
+
+        self.m.VerifyAll()
+
+    def test_suspend(self):
+        rsrc = self.create_alarm()
+        self.m.StubOutWithMock(self.fc.alarms, 'update')
+        self.fc.alarms.update(alarm_id='foo', enabled=False)
+
+        self.m.ReplayAll()
+        scheduler.TaskRunner(rsrc.create)()
+
+        scheduler.TaskRunner(rsrc.suspend)()
+        self.assertEqual((rsrc.SUSPEND, rsrc.COMPLETE), rsrc.state)
+
+        self.m.VerifyAll()
+
+    def test_resume(self):
+        rsrc = self.create_alarm()
+        self.m.StubOutWithMock(self.fc.alarms, 'update')
+        self.fc.alarms.update(alarm_id='foo', enabled=True)
+
+        self.m.ReplayAll()
+        scheduler.TaskRunner(rsrc.create)()
+        rsrc.state_set(rsrc.SUSPEND, rsrc.COMPLETE)
+
+        scheduler.TaskRunner(rsrc.resume)()
+        self.assertEqual((rsrc.RESUME, rsrc.COMPLETE), rsrc.state)
+
+        self.m.VerifyAll()
+
+    def test_delete(self):
+        rsrc = self.create_alarm()
+        self.m.StubOutWithMock(self.fc.alarms, 'delete')
+        self.fc.alarms.delete('foo')
+        self.m.ReplayAll()
+        scheduler.TaskRunner(rsrc.create)()
+        scheduler.TaskRunner(rsrc.delete)()
+        self.assertEqual((rsrc.DELETE, rsrc.COMPLETE), rsrc.state)
+
+        self.m.VerifyAll()
+
+    def test_delete_not_found(self):
+        rsrc = self.create_alarm()
+        self.m.StubOutWithMock(self.fc.alarms, 'delete')
+        self.fc.alarms.delete('foo').AndRaise(
+            ceilometerclient_exc.HTTPNotFound())
+        self.m.ReplayAll()
+        scheduler.TaskRunner(rsrc.create)()
+        scheduler.TaskRunner(rsrc.delete)()
+        self.assertEqual((rsrc.DELETE, rsrc.COMPLETE), rsrc.state)
+
+        self.m.VerifyAll()
+
+    def _prepare_check_resource(self):
+        snippet = template_format.parse(gnocchi_resources_alarm_template)
+        stack = utils.parse_stack(snippet)
+        res = stack['GnoResAlarm']
+        res.ceilometer = mock.Mock()
+        mock_alarm = mock.Mock(enabled=True, state='ok')
+        res.ceilometer().alarms.get.return_value = mock_alarm
+        return res
+
+    def test_check(self):
+        res = self._prepare_check_resource()
+        scheduler.TaskRunner(res.check)()
+        self.assertEqual((res.CHECK, res.COMPLETE), res.state)
+
+    def test_check_failure(self):
+        res = self._prepare_check_resource()
+        res.ceilometer().alarms.get.side_effect = Exception('Boom')
+
+        self.assertRaises(exception.ResourceFailure,
+                          scheduler.TaskRunner(res.check))
+        self.assertEqual((res.CHECK, res.FAILED), res.state)
+        self.assertIn('Boom', res.status_reason)
+
+
+class GnocchiMetricsAlarmTest(common.HeatTestCase):
+
+    def setUp(self):
+        super(GnocchiMetricsAlarmTest, self).setUp()
+        self.fc = FakeCeilometerClient()
+        resource._register_class("OS::Ceilometer::GnocchiMetricsAlarm",
+                                 gnocchi_alarm.CeilometerGnocchiMetricsAlarm)
+        self.m.StubOutWithMock(ceilometer.CeilometerClientPlugin, '_create')
+
+    def create_alarm(self):
+        ceilometer.CeilometerClientPlugin._create().AndReturn(
+            self.fc)
+        self.m.StubOutWithMock(self.fc.alarms, 'create')
+        self.fc.alarms.create(
+            alarm_actions=[],
+            description=u'Do stuff with gnocchi metrics',
+            enabled=True,
+            insufficient_data_actions=None,
+            ok_actions=None,
+            name=mox.IgnoreArg(), type='gnocchi_metrics_threshold',
+            repeat_actions=True,
+            gnocchi_metrics_threshold_rule={
+                "aggregation_method": "mean",
+                "granularity": 60,
+                "evaluation_periods": 1,
+                "threshold": 50,
+                "comparison_operator": "gt",
+                "metrics": ["911fce07-e0d7-4210-8c8c-4a9d811fcabc",
+                            "2543d435-fe93-4443-9351-fb0156930f94"],
+            }
+        ).AndReturn(FakeCeilometerAlarm())
+        snippet = template_format.parse(gnocchi_metrics_alarm_template)
+        stack = utils.parse_stack(snippet)
+        resource_defns = stack.t.resource_definitions(stack)
+        return gnocchi_alarm.CeilometerGnocchiMetricsAlarm(
+            'GnoMetricsAlarm', resource_defns['GnoMetricsAlarm'], stack)
+
+    def test_create(self):
+        rsrc = self.create_alarm()
+
+        self.m.ReplayAll()
+        scheduler.TaskRunner(rsrc.create)()
+        self.assertEqual((rsrc.CREATE, rsrc.COMPLETE), rsrc.state)
+        self.assertEqual('foo', rsrc.resource_id)
+        self.m.VerifyAll()
+
+    def test_update(self):
+        rsrc = self.create_alarm()
+        self.m.StubOutWithMock(self.fc.alarms, 'update')
+        self.fc.alarms.update(
+            alarm_id='foo',
+            gnocchi_metrics_threshold_rule={
+                'metrics': ['d3d6c642-921e-4fc2-9c5f-15d9a5afb598',
+                            'bc60f822-18a0-4a0c-94e7-94c554b00901']})
+
+        self.m.ReplayAll()
+        scheduler.TaskRunner(rsrc.create)()
+
+        update_template = copy.deepcopy(rsrc.t)
+        update_template['Properties']['metrics'] = [
+            'd3d6c642-921e-4fc2-9c5f-15d9a5afb598',
+            'bc60f822-18a0-4a0c-94e7-94c554b00901']
+        scheduler.TaskRunner(rsrc.update, update_template)()
+        self.assertEqual((rsrc.UPDATE, rsrc.COMPLETE), rsrc.state)
+
+        self.m.VerifyAll()
+
+    def test_suspend(self):
+        rsrc = self.create_alarm()
+        self.m.StubOutWithMock(self.fc.alarms, 'update')
+        self.fc.alarms.update(alarm_id='foo', enabled=False)
+
+        self.m.ReplayAll()
+        scheduler.TaskRunner(rsrc.create)()
+
+        scheduler.TaskRunner(rsrc.suspend)()
+        self.assertEqual((rsrc.SUSPEND, rsrc.COMPLETE), rsrc.state)
+
+        self.m.VerifyAll()
+
+    def test_resume(self):
+        rsrc = self.create_alarm()
+        self.m.StubOutWithMock(self.fc.alarms, 'update')
+        self.fc.alarms.update(alarm_id='foo', enabled=True)
+
+        self.m.ReplayAll()
+        scheduler.TaskRunner(rsrc.create)()
+        rsrc.state_set(rsrc.SUSPEND, rsrc.COMPLETE)
+
+        scheduler.TaskRunner(rsrc.resume)()
+        self.assertEqual((rsrc.RESUME, rsrc.COMPLETE), rsrc.state)
+
+        self.m.VerifyAll()
+
+    def test_delete(self):
+        rsrc = self.create_alarm()
+        self.m.StubOutWithMock(self.fc.alarms, 'delete')
+        self.fc.alarms.delete('foo')
+        self.m.ReplayAll()
+        scheduler.TaskRunner(rsrc.create)()
+        scheduler.TaskRunner(rsrc.delete)()
+        self.assertEqual((rsrc.DELETE, rsrc.COMPLETE), rsrc.state)
+
+        self.m.VerifyAll()
+
+    def test_delete_not_found(self):
+        rsrc = self.create_alarm()
+        self.m.StubOutWithMock(self.fc.alarms, 'delete')
+        self.fc.alarms.delete('foo').AndRaise(
+            ceilometerclient_exc.HTTPNotFound())
+        self.m.ReplayAll()
+        scheduler.TaskRunner(rsrc.create)()
+        scheduler.TaskRunner(rsrc.delete)()
+        self.assertEqual((rsrc.DELETE, rsrc.COMPLETE), rsrc.state)
+
+        self.m.VerifyAll()
+
+    def _prepare_check_resource(self):
+        snippet = template_format.parse(gnocchi_metrics_alarm_template)
+        stack = utils.parse_stack(snippet)
+        res = stack['GnoMetricsAlarm']
+        res.ceilometer = mock.Mock()
+        mock_alarm = mock.Mock(enabled=True, state='ok')
+        res.ceilometer().alarms.get.return_value = mock_alarm
+        return res
+
+    def test_check(self):
+        res = self._prepare_check_resource()
+        scheduler.TaskRunner(res.check)()
+        self.assertEqual((res.CHECK, res.COMPLETE), res.state)
+
+    def test_check_failure(self):
+        res = self._prepare_check_resource()
+        res.ceilometer().alarms.get.side_effect = Exception('Boom')
+
+        self.assertRaises(exception.ResourceFailure,
+                          scheduler.TaskRunner(res.check))
+        self.assertEqual((res.CHECK, res.FAILED), res.state)
+        self.assertIn('Boom', res.status_reason)

contrib/heat_gnocchi/setup.cfg

@@ -0,0 +1,29 @@
+[metadata]
+name = heat-contrib-gnocchi
+summary = Heat resources for working gnocchi queues
+description-file =
+    README.md
+author = OpenStack
+author-email = openstack-dev@lists.openstack.org
+home-page = http://www.openstack.org/
+classifier =
+    Environment :: OpenStack
+    Intended Audience :: Information Technology
+    Intended Audience :: System Administrators
+    License :: OSI Approved :: Apache Software License
+    Operating System :: POSIX :: Linux
+    Programming Language :: Python
+    Programming Language :: Python :: 2
+    Programming Language :: Python :: 2.7
+    Programming Language :: Python :: 2.6
+
+[files]
+packages =
+    heat_gnocchi
+# Copy to /usr/lib/heat for plugin loading
+data_files =
+    lib/heat/gnocchi = heat_gnocchi/resources/*
+
+[global]
+setup-hooks =
+    pbr.hooks.setup_hook

contrib/heat_gnocchi/setup.py

@@ -0,0 +1,30 @@
+#!/usr/bin/env python
+# Copyright (c) 2013 Hewlett-Packard Development Company, L.P.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# THIS FILE IS MANAGED BY THE GLOBAL REQUIREMENTS REPO - DO NOT EDIT
+import setuptools
+
+# In python < 2.7.4, a lazy loading of package `pbr` will break
+# setuptools if some other modules registered functions in `atexit`.
+# solution from: http://bugs.python.org/issue15881#msg170215
+try:
+    import multiprocessing  # noqa
+except ImportError:
+    pass
+
+setuptools.setup(
+    setup_requires=['pbr'],
+    pbr=True)

heat/engine/resources/ceilometer/alarm.py

@@ -313,51 +313,26 @@ class CeilometerAlarm(resource.Resource):
         self.ceilometer().alarms.get(self.resource_id)
 
 
-class CombinationAlarm(resource.Resource):
+class BaseCeilometerAlarm(resource.Resource):
-
-    support_status = support.SupportStatus(version='2014.1')
-
-    PROPERTIES = (
-        ALARM_IDS, OPERATOR,
-    ) = (
-        'alarm_ids', 'operator',
-    )
-
-    properties_schema = {
-        ALARM_IDS: properties.Schema(
-            properties.Schema.LIST,
-            _('List of alarm identifiers to combine.'),
-            required=True,
-            constraints=[constraints.Length(min=1)],
-            update_allowed=True),
-        OPERATOR: properties.Schema(
-            properties.Schema.STRING,
-            _('Operator used to combine the alarms.'),
-            constraints=[constraints.AllowedValues(['and', 'or'])],
-            update_allowed=True)
-    }
-    properties_schema.update(common_properties_schema)
-
     default_client_name = 'ceilometer'
 
     def handle_create(self):
         properties = actions_to_urls(self.stack,
                                      self.properties)
         properties['name'] = self.physical_resource_name()
-        properties['type'] = 'combination'
+        properties['type'] = self.ceilometer_alarm_type
-
         alarm = self.ceilometer().alarms.create(
             **self._reformat_properties(properties))
         self.resource_id_set(alarm.alarm_id)
 
     def _reformat_properties(self, properties):
-        combination_rule = {}
+        rule = {}
-        for name in [self.ALARM_IDS, self.OPERATOR]:
+        for name in self.PROPERTIES:
             value = properties.pop(name, None)
             if value:
-                combination_rule[name] = value
+                rule[name] = value
-        if combination_rule:
+        if rule:
-            properties['combination_rule'] = combination_rule
+            properties['%s_rule' % self.ceilometer_alarm_type] = rule
         return properties
 
     def handle_update(self, json_snippet, tmpl_diff, prop_diff):
@@ -386,6 +361,34 @@ class CombinationAlarm(resource.Resource):
         self.ceilometer().alarms.get(self.resource_id)
 
 
+class CombinationAlarm(BaseCeilometerAlarm):
+
+    support_status = support.SupportStatus(version='2014.1')
+
+    PROPERTIES = (
+        ALARM_IDS, OPERATOR,
+    ) = (
+        'alarm_ids', 'operator',
+    )
+
+    properties_schema = {
+        ALARM_IDS: properties.Schema(
+            properties.Schema.LIST,
+            _('List of alarm identifiers to combine.'),
+            required=True,
+            constraints=[constraints.Length(min=1)],
+            update_allowed=True),
+        OPERATOR: properties.Schema(
+            properties.Schema.STRING,
+            _('Operator used to combine the alarms.'),
+            constraints=[constraints.AllowedValues(['and', 'or'])],
+            update_allowed=True)
+    }
+    properties_schema.update(common_properties_schema)
+
+    ceilometer_alarm_type = 'combination'
+
+
 def resource_mapping():
     return {
         'OS::Ceilometer::Alarm': CeilometerAlarm,