Merge "Automatically create groups that do not exist"

nova/api/openstack/compute/contrib/server_groups.py

@@ -28,6 +28,9 @@ from nova.objects import instance_group as instance_group_obj
 from nova.openstack.common.gettextutils import _
 from nova import utils
 
+# NOTE(russellb) There is one other policy, 'legacy', but we don't allow that
+# being set via the API.  It's only used when a group gets automatically
+# created to support the legacy behavior of the 'group' scheduler hint.
 SUPPORTED_POLICIES = ['anti-affinity', 'affinity']
 
 authorize = extensions.extension_authorizer('compute', 'server_groups')

nova/compute/api.py

@@ -875,16 +875,44 @@ class API(base.Base):
 
         return {}
 
+    @staticmethod
+    def _update_instance_group_by_name(context, instance_uuids, group_name):
+        try:
+            ig = instance_group_obj.InstanceGroup.get_by_name(context,
+                    group_name)
+            instance_group_obj.InstanceGroup.add_members(context, ig.uuid,
+                    instance_uuids)
+        except exception.InstanceGroupNotFound:
+            # NOTE(russellb) If the group does not already exist, we need to
+            # automatically create it to be backwards compatible with old
+            # handling of the 'group' scheduler hint.  The policy type will be
+            # 'legacy', indicating that this group was created to emulate
+            # legacy group behavior.
+            ig = instance_group_obj.InstanceGroup()
+            ig.name = group_name
+            ig.project_id = context.project_id
+            ig.user_id = context.user_id
+            ig.policies = ['legacy']
+            ig.members = instance_uuids
+            ig.create(context)
+
     @staticmethod
     def _update_instance_group(context, instances, scheduler_hints):
         if not scheduler_hints:
             return
-        group_uuid = scheduler_hints.get('group')
-        if not group_uuid:
+
+        group_hint = scheduler_hints.get('group')
+        if not group_hint:
             return
+
         instance_uuids = [instance.uuid for instance in instances]
-        instance_group_obj.InstanceGroup.add_members(context, group_uuid,
-                instance_uuids)
+
+        if uuidutils.is_uuid_like(group_hint):
+            instance_group_obj.InstanceGroup.add_members(context, group_hint,
+                    instance_uuids)
+        else:
+            API._update_instance_group_by_name(context, instance_uuids,
+                    group_hint)
 
     def _create_instance(self, context, instance_type,
                image_href, kernel_id, ramdisk_id,

nova/tests/compute/test_compute.py

@@ -6941,6 +6941,36 @@ class ComputeAPITestCase(BaseTestCase):
 
         db.instance_destroy(self.context, refs[0]['uuid'])
 
+    def test_instance_create_auto_creates_group(self):
+        self.stubs.Set(fake_image._FakeImageService, 'show', self.fake_show)
+
+        inst_type = flavors.get_default_flavor()
+        (refs, resv_id) = self.compute_api.create(
+            self.context, inst_type, self.fake_image['id'],
+            scheduler_hints={'group': 'groupname'})
+
+        group = instance_group_obj.InstanceGroup.get_by_name(self.context,
+                'groupname')
+        self.assertEqual('groupname', group.name)
+        self.assertIn('legacy', group.policies)
+        self.assertEqual(1, len(group.members))
+        self.assertIn(refs[0]['uuid'], group.members)
+
+        # On a second instance, make sure it gets added to the group that was
+        # auto-created above
+        (refs2, resv_id) = self.compute_api.create(
+            self.context, inst_type, self.fake_image['id'],
+            scheduler_hints={'group': 'groupname'})
+        group = instance_group_obj.InstanceGroup.get_by_name(self.context,
+                'groupname')
+        self.assertEqual('groupname', group.name)
+        self.assertIn('legacy', group.policies)
+        self.assertEqual(2, len(group.members))
+        self.assertIn(refs[0]['uuid'], group.members)
+        self.assertIn(refs2[0]['uuid'], group.members)
+
+        db.instance_destroy(self.context, refs[0]['uuid'])
+
     def test_destroy_instance_disassociates_security_groups(self):
         # Make sure destroying disassociates security groups.
         group = self._create_group()