Merge "Adapt _validate_instance_group_policy to new policy model"

nova/compute/manager.py

@@ -1275,15 +1275,28 @@ class ComputeManager(manager.Manager):
         @utils.synchronized(group_hint)
         def _do_validation(context, instance, group_hint):
             group = objects.InstanceGroup.get_by_hint(context, group_hint)
-            if 'anti-affinity' in group.policies:
-                group_hosts = group.get_hosts(exclude=[instance.uuid])
-                if self.host in group_hosts:
+            if group.policy and 'anti-affinity' == group.policy:
+                instances_uuids = objects.InstanceList.get_uuids_by_host(
+                    context, self.host)
+                ins_on_host = set(instances_uuids)
+                members = set(group.members)
+                # Determine the set of instance group members on this host
+                # which are not the instance in question. This is used to
+                # determine how many other members from the same anti-affinity
+                # group can be on this host.
+                members_on_host = ins_on_host & members - set([instance.uuid])
+                rules = group.rules
+                if rules and 'max_server_per_host' in rules:
+                    max_server = rules['max_server_per_host']
+                else:
+                    max_server = 1
+                if len(members_on_host) >= max_server:
                     msg = _("Anti-affinity instance group policy "
                             "was violated.")
                     raise exception.RescheduledException(
                             instance_uuid=instance.uuid,
                             reason=msg)
-            elif 'affinity' in group.policies:
+            elif group.policy and 'affinity' == group.policy:
                 group_hosts = group.get_hosts(exclude=[instance.uuid])
                 if group_hosts and self.host not in group_hosts:
                     msg = _("Affinity instance group policy was violated.")

nova/objects/service.py

@@ -31,7 +31,7 @@ LOG = logging.getLogger(__name__)
 
 
 # NOTE(danms): This is the global service version counter
-SERVICE_VERSION = 32
+SERVICE_VERSION = 33
 
 
 # NOTE(danms): This is our SERVICE_VERSION history. The idea is that any
@@ -138,6 +138,9 @@ SERVICE_VERSION_HISTORY = (
     # migration if 'file_backed_memory' is enabled and the source does not
     # support 'file_backed_memory'
     {'compute_rpc': '5.0'},
+    # Version 33: Add support for check on the server group with
+    # 'max_server_per_host' rules
+    {'compute_rpc': '5.0'},
 )
 
 

nova/tests/unit/compute/test_compute_mgr.py

@@ -5720,7 +5720,7 @@ class ComputeManagerBuildInstanceTestCase(test.NoDBTestCase):
     def test_validate_policy_honors_workaround_disabled(self, mock_get):
         instance = objects.Instance(uuid=uuids.instance)
         hints = {'group': 'foo'}
-        mock_get.return_value = objects.InstanceGroup(policies=[])
+        mock_get.return_value = objects.InstanceGroup(policy=None)
         self.compute._validate_instance_group_policy(self.context,
                                                      instance, hints)
         mock_get.assert_called_once_with(self.context, 'foo')
@@ -5746,6 +5746,32 @@ class ComputeManagerBuildInstanceTestCase(test.NoDBTestCase):
                                                      instance, hints)
         mock_get.assert_called_once_with(self.context, uuids.group_hint)
 
+    @mock.patch('nova.objects.InstanceList.get_uuids_by_host')
+    @mock.patch('nova.objects.InstanceGroup.get_by_hint')
+    def test_validate_instance_group_policy_with_rules(self, mock_get_by_hint,
+                                                       mock_get_by_host):
+        # Create 2 instance in same host, inst2 created before inst1
+        instance = objects.Instance(uuid=uuids.inst1)
+        hints = {'group': [uuids.group_hint]}
+        existing_insts = [uuids.inst1, uuids.inst2]
+        members_uuids = [uuids.inst1, uuids.inst2]
+        mock_get_by_host.return_value = existing_insts
+
+        # if group policy rules limit to 1, raise RescheduledException
+        mock_get_by_hint.return_value = objects.InstanceGroup(
+            policy='anti-affinity', rules={'max_server_per_host': '1'},
+            hosts=['host1'], members=members_uuids)
+        self.assertRaises(exception.RescheduledException,
+                          self.compute._validate_instance_group_policy,
+                          self.context, instance, hints)
+
+        # if group policy rules limit change to 2, validate OK
+        mock_get_by_hint.return_value = objects.InstanceGroup(
+            policy='anti-affinity', rules={'max_server_per_host': 2},
+            hosts=['host1'], members=members_uuids)
+        self.compute._validate_instance_group_policy(self.context,
+                                                     instance, hints)
+
     @mock.patch.object(virt_driver.ComputeDriver,
                        'prepare_networks_before_block_device_mapping')
     @mock.patch.object(virt_driver.ComputeDriver,