Fix missing obj_make_compatible() for ImageMetaProps object

This object was never added with an obj_make_compatible() handler for
the many versions we've had since its introduction. This adds that,
rules for the existing versions, and a test for the future.

Note that version 1.6 added values to an enum, so this validates that
an exception is raised during backporting if that field has a value
that would be invalid for the requested version.

Change-Id: I64d40b6fe5e738cf32537c73b9fec57a7fbcdf2d

nova/objects/image_meta.py

@@ -14,6 +14,7 @@
 
 import copy
 
+from nova import exception
 from nova import objects
 from nova.objects import base
 from nova.objects import fields
@@ -147,6 +148,30 @@ class ImageMetaProps(base.NovaObject):
     # Version 1.7: added img_config_drive field
     VERSION = ImageMeta.VERSION
 
+    def obj_make_compatible(self, primitive, target_version):
+        super(ImageMetaProps, self).obj_make_compatible(primitive,
+                                                        target_version)
+        target_version = utils.convert_version_to_tuple(target_version)
+        if target_version < (1, 7):
+            primitive.pop('img_config_drive', None)
+        if target_version < (1, 5):
+            primitive.pop('os_admin_user', None)
+        if target_version < (1, 4):
+            primitive.pop('hw_vif_multiqueue_enabled', None)
+        if target_version < (1, 2):
+            primitive.pop('img_hv_type', None)
+            primitive.pop('img_hv_requested_version', None)
+        if target_version < (1, 1):
+            primitive.pop('os_require_quiesce', None)
+
+        if target_version < (1, 6):
+            bus = primitive.get('hw_disk_bus', None)
+            if bus in ('lxc', 'uml'):
+                raise exception.ObjectActionError(
+                    action='obj_make_compatible',
+                    reason='hw_disk_bus=%s not supported in version %s' % (
+                        bus, target_version))
+
     # Maximum number of NUMA nodes permitted for the guest topology
     NUMA_NODES_MAX = 128
 

nova/tests/unit/objects/test_image_meta.py

@@ -14,6 +14,7 @@
 
 import datetime
 
+from nova import exception
 from nova import objects
 from nova import test
 
@@ -274,3 +275,23 @@ class TestImageMetaProps(test.NoDBTestCase):
         self.assertIsNone(virtprops.get("hw_numa_nodes"))
         self.assertEqual([set([0, 1, 2, 3])],
                          virtprops.hw_numa_cpus)
+
+    def test_obj_make_compatible(self):
+        props = {
+            'img_config_drive': 'mandatory',
+            'os_admin_user': 'root',
+            'hw_vif_multiqueue_enabled': True,
+            'img_hv_type': 'kvm',
+            'img_hv_requested_version': '>= 1.0',
+            'os_require_quiesce': True,
+        }
+
+        obj = objects.ImageMetaProps(**props)
+        primitive = obj.obj_to_primitive('1.0')
+        self.assertFalse(any([x in primitive['nova_object.data']
+                              for x in props]))
+
+        for bus in ('lxc', 'uml'):
+            obj.hw_disk_bus = bus
+            self.assertRaises(exception.ObjectActionError,
+                              obj.obj_to_primitive, '1.0')