Added support of availability zones for compute.

models.Service got additional field availability_zone and was created ZoneScheduler that make decisions based on this field. 
Also replaced fake 'nova' zone in EC2 cloud api.

Authors

@@ -15,6 +15,7 @@ Eldar Nugaev <enugaev@griddynamics.com>
 Eric Day <eday@oddments.org>
 Ewan Mellor <ewan.mellor@citrix.com>
 Hisaki Ohara <hisaki.ohara@intel.com>
+Ilya Alekseyev <ialekseev@griddynamics.com>
 Jay Pipes <jaypipes@gmail.com>
 Jesse Andrews <anotherjesse@gmail.com>
 Joe Heck <heckj@mac.com>

nova/flags.py

@@ -308,6 +308,5 @@ DEFINE_string('image_service', 'nova.image.s3.S3ImageService',
 DEFINE_string('host', socket.gethostname(),
               'name of this node')
 
-# UNUSED
 DEFINE_string('node_availability_zone', 'nova',
               'availability zone of this node')

nova/scheduler/zone.py

@@ -0,0 +1,56 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright (c) 2010 Openstack, LLC.
+# Copyright 2010 United States Government as represented by the
+# Administrator of the National Aeronautics and Space Administration.
+# All Rights Reserved.
+#
+#    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.
+
+"""
+Availability Zone Scheduler implementation
+"""
+
+import random
+
+from nova.scheduler import driver
+from nova import db
+
+
+class ZoneScheduler(driver.Scheduler):
+    """Implements Scheduler as a random node selector."""
+
+    def hosts_up_with_zone(self, context, topic, zone):
+        """Return the list of hosts that have a running service
+        for topic and availability zone (if defined).
+        """
+
+        if zone is None:
+            return self.hosts_up(context, topic)
+
+        services = db.service_get_all_by_topic(context, topic)
+        return [service.host
+                for service in services
+                if self.service_is_up(service)
+                and service.availability_zone == zone]
+
+    def schedule(self, context, topic, *_args, **_kwargs):
+        """Picks a host that is up at random in selected
+        availability zone (if defined).
+        """
+
+        zone = _kwargs.get('availability_zone')
+        hosts = self.hosts_up_with_zone(context, topic, zone)
+        if not hosts:
+            raise driver.NoValidHost(_("No hosts found"))
+        return hosts[int(random.random() * len(hosts))]

nova/tests/test_cloud.py

@@ -133,10 +133,35 @@ class CloudTestCase(test.TestCase):
         db.volume_destroy(self.context, vol1['id'])
         db.volume_destroy(self.context, vol2['id'])
 
+    def test_describe_availability_zones(self):
+        """Makes sure describe_availability_zones works and filters results."""
+        service1 = db.service_create(self.context, {'host': 'host1_zones',
+                                         'binary': "nova-compute",
+                                         'topic': 'compute',
+                                         'report_count': 0,
+                                         'availability_zone': "zone1"})
+        service2 = db.service_create(self.context, {'host': 'host2_zones',
+                                         'binary': "nova-compute",
+                                         'topic': 'compute',
+                                         'report_count': 0,
+                                         'availability_zone': "zone2"})
+        result = self.cloud.describe_availability_zones(self.context)
+        self.assertEqual(len(result['availabilityZoneInfo']), 3)
+        db.service_destroy(self.context, service1['id'])
+        db.service_destroy(self.context, service2['id'])
+
     def test_describe_instances(self):
         """Makes sure describe_instances works and filters results."""
-        inst1 = db.instance_create(self.context, {'reservation_id': 'a'})
+        inst1 = db.instance_create(self.context, {'reservation_id': 'a',
-        inst2 = db.instance_create(self.context, {'reservation_id': 'a'})
+                                                  'host': 'host1'})
+        inst2 = db.instance_create(self.context, {'reservation_id': 'a',
+                                                  'host': 'host2'})
+        comp1 = db.service_create(self.context, {'host': 'host1',
+                                                 'availability_zone': 'zone1',
+                                                 'topic': "compute"})
+        comp2 = db.service_create(self.context, {'host': 'host2',
+                                                 'availability_zone': 'zone2',
+                                                 'topic': "compute"})
         result = self.cloud.describe_instances(self.context)
         result = result['reservationSet'][0]
         self.assertEqual(len(result['instancesSet']), 2)
@@ -147,8 +172,12 @@ class CloudTestCase(test.TestCase):
         self.assertEqual(len(result['instancesSet']), 1)
         self.assertEqual(result['instancesSet'][0]['instanceId'],
                          instance_id)
+        self.assertEqual(result['instancesSet'][0]
+                         ['placement']['availabilityZone'], 'zone2')
         db.instance_destroy(self.context, inst1['id'])
         db.instance_destroy(self.context, inst2['id'])
+        db.service_destroy(self.context, comp1['id'])
+        db.service_destroy(self.context, comp2['id'])
 
     def test_console_output(self):
         image_id = FLAGS.default_image
@@ -241,6 +270,19 @@ class CloudTestCase(test.TestCase):
                 LOG.debug(_("Terminating instance %s"), instance_id)
                 rv = self.compute.terminate_instance(instance_id)
 
+    def test_describe_instances(self):
+        """Makes sure describe_instances works."""
+        instance1 = db.instance_create(self.context, {'host': 'host2'})
+        comp1 = db.service_create(self.context, {'host': 'host2',
+                                                 'availability_zone': 'zone1',
+                                                 'topic': "compute"})
+        result = self.cloud.describe_instances(self.context)
+        self.assertEqual(result['reservationSet'][0]
+                         ['instancesSet'][0]
+                         ['placement']['availabilityZone'], 'zone1')
+        db.instance_destroy(self.context, instance1['id'])
+        db.service_destroy(self.context, comp1['id'])
+
     def test_instance_update_state(self):
         def instance(num):
             return {

nova/tests/test_scheduler.py

@@ -21,6 +21,7 @@ Tests For Scheduler
 
 import datetime
 
+from mox import IgnoreArg
 from nova import context
 from nova import db
 from nova import flags
@@ -76,6 +77,59 @@ class SchedulerTestCase(test.TestCase):
         scheduler.named_method(ctxt, 'topic', num=7)
 
 
+class ZoneSchedulerTestCase(test.TestCase):
+    """Test case for zone scheduler"""
+    def setUp(self):
+        super(ZoneSchedulerTestCase, self).setUp()
+        self.flags(scheduler_driver='nova.scheduler.zone.ZoneScheduler')
+
+    def _create_service_model(self, **kwargs):
+        service = db.sqlalchemy.models.Service()
+        service.host = kwargs['host']
+        service.disabled = False
+        service.deleted = False
+        service.report_count = 0
+        service.binary = 'nova-compute'
+        service.topic = 'compute'
+        service.id = kwargs['id']
+        service.availability_zone = kwargs['zone']
+        service.created_at = datetime.datetime.utcnow()
+        return service
+
+    def test_with_two_zones(self):
+        scheduler = manager.SchedulerManager()
+        ctxt = context.get_admin_context()
+        service_list = [self._create_service_model(id=1,
+                                                   host='host1',
+                                                   zone='zone1'),
+                        self._create_service_model(id=2,
+                                                   host='host2',
+                                                   zone='zone2'),
+                        self._create_service_model(id=3,
+                                                   host='host3',
+                                                   zone='zone2'),
+                        self._create_service_model(id=4,
+                                                   host='host4',
+                                                   zone='zone2'),
+                        self._create_service_model(id=5,
+                                                   host='host5',
+                                                   zone='zone2')]
+        self.mox.StubOutWithMock(db, 'service_get_all_by_topic')
+        arg = IgnoreArg()
+        db.service_get_all_by_topic(arg, arg).AndReturn(service_list)
+        self.mox.StubOutWithMock(rpc, 'cast', use_mock_anything=True)
+        rpc.cast(ctxt,
+                 'compute.host1',
+                 {'method': 'run_instance',
+                  'args': {'instance_id': 'i-ffffffff',
+                           'availability_zone': 'zone1'}})
+        self.mox.ReplayAll()
+        scheduler.run_instance(ctxt,
+                               'compute',
+                               instance_id='i-ffffffff',
+                               availability_zone='zone1')
+
+
 class SimpleDriverTestCase(test.TestCase):
     """Test case for simple driver"""
     def setUp(self):