Fix ServerGroup create

Nova api has a different signature from microversion
2.64 onwards[1].

Also adds support_status for 'rules' property missed
earlier in I8e77f54303298da00cbe719afccb449f10fe387c.

[1] https://github.com/openstack/python-novaclient/blob/master/novaclient/v2/server_groups.py#L103-L104

Task: 43168
Task: 43661
Change-Id: If7138c71044adadaf7de255a2fac463b57ff3c47
(cherry picked from commit 9aedaa6d8a,
 e70ff2e153)

heat/engine/resources/openstack/nova/server_group.py

@@ -35,11 +35,13 @@ class ServerGroup(resource.Resource):
     entity = 'server_groups'
 
     PROPERTIES = (
-        NAME, POLICIES, RULE
+        NAME, POLICIES, RULES
     ) = (
-        'name', 'policies', 'rule'
+        'name', 'policies', 'rules'
     )
 
+    _RULES = (MAX_SERVER_PER_HOST) = ('max_server_per_host')
+
     properties_schema = {
         NAME: properties.Schema(
             properties.Schema.STRING,
@@ -47,7 +49,7 @@ class ServerGroup(resource.Resource):
         ),
         POLICIES: properties.Schema(
             properties.Schema.LIST,
-            _('A list of string policies to apply. '
+            _('A list of exactly one policy to apply. '
               'Defaults to anti-affinity.'),
             default=['anti-affinity'],
             constraints=[
@@ -59,11 +61,17 @@ class ServerGroup(resource.Resource):
                 properties.Schema.STRING,
             ),
         ),
-        RULE: properties.Schema(
+        RULES: properties.Schema(
             properties.Schema.MAP,
-            _('A rule for the policy. Currently, only the '
-              '"max_server_per_host" rule is supported for the '
-              '"anti-affinity" policy.'),
+            _('Rules for a policy.'),
+            schema={
+                MAX_SERVER_PER_HOST: properties.Schema(
+                    properties.Schema.NUMBER,
+                    _('Maximum servers in a group on a given host. '
+                      'Rule for anti-affinity policy.')
+                )
+            },
+            support_status=support.SupportStatus(version='17.0.0'),
         ),
     }
 
@@ -77,26 +85,25 @@ class ServerGroup(resource.Resource):
             msg = _('Required microversion for soft policies not supported.')
             raise exception.StackValidationFailed(message=msg)
 
-        if self.properties[self.RULE]:
+        if self.properties[self.RULES]:
             is_supported = self.client_plugin().is_version_supported(
                 MICROVERSION_RULE)
             if not is_supported:
-                msg = _('Required microversion for rule not supported.')
+                msg = _('Required microversion for rules not supported.')
                 raise exception.StackValidationFailed(message=msg)
 
     def handle_create(self):
         name = self.physical_resource_name()
         policies = self.properties[self.POLICIES]
-        if self.properties[self.RULE] and 'soft-affinity' in policies:
-            rule = self.properties[self.RULE]
-            client = self.client()
-            server_group = client.server_groups.create(name=name,
-                                                       policies=policies,
-                                                       rule=rule)
+        rules = self.properties[self.RULES]
+        rules_supported = self.client_plugin().is_version_supported(
+            MICROVERSION_RULE)
+        if rules_supported:
+            server_group = self.client().server_groups.create(
+                name=name, policy=policies[0], rules=rules)
         else:
-            client = self.client()
-            server_group = client.server_groups.create(name=name,
-                                                       policies=policies)
+            server_group = self.client().server_groups.create(
+                name=name, policies=policies)
         self.resource_id_set(server_group.id)
 
     def physical_resource_name(self):

heat/tests/openstack/nova/test_server_group.py

@@ -26,7 +26,9 @@ sg_template = {
             "type": "OS::Nova::ServerGroup",
             "properties": {
                 "name": "test",
-                "policies": ["anti-affinity"]
+                "policies": ["anti-affinity"],
+                "rules": {
+                    "max_server_per_host": 8}
             }
         }
     }
@@ -50,6 +52,12 @@ class NovaServerGroupTest(common.HeatTestCase):
         # create mock clients and objects
         nova = mock.MagicMock()
         self.sg.client = mock.MagicMock(return_value=nova)
+        mock_plugin = mock.MagicMock()
+        self.patchobject(mock_plugin,
+                         'is_version_supported',
+                         return_value=True)
+        self.patchobject(self.sg, 'client_plugin',
+                         return_value=mock_plugin)
         self.sg_mgr = nova.server_groups
 
     def _create_sg(self, name):
@@ -68,7 +76,7 @@ class NovaServerGroupTest(common.HeatTestCase):
             name = 'test'
             n = name
 
-            def fake_create(name, policies):
+            def fake_create(name, policy, rules):
                 self.assertGreater(len(name), 1)
                 return FakeGroup(n)
             self.sg_mgr.create = fake_create
@@ -81,7 +89,9 @@ class NovaServerGroupTest(common.HeatTestCase):
         self._create_sg('test')
         expected_args = ()
         expected_kwargs = {'name': 'test',
-                           'policies': ["anti-affinity"],
+                           'policy': "anti-affinity",
+                           'rules': {
+                               'max_server_per_host': 8}
                            }
         self.sg_mgr.create.assert_called_once_with(*expected_args,
                                                    **expected_kwargs)