Add missing image to instance booted from volume

When booting an instance from a volume, the image_ref for
the instance will be None. And the API do not get the image
information for the instance also. So when we calling the
related API, we get "" for instance.image.

Change-Id: I3c35ab1d7c8bcec551fb5d67d0b44418266b32a4
Closes-bug: 1317880

nova/api/openstack/compute/servers.py

@@ -34,6 +34,7 @@ from nova import compute
 from nova.compute import flavors
 from nova import exception
 from nova import objects
+from nova.objects import instance as instance_obj
 from nova.openstack.common.gettextutils import _
 from nova.openstack.common import log as logging
 from nova.openstack.common import strutils
@@ -599,6 +600,8 @@ class Controller(wsgi.Controller):
                                                      limit=limit,
                                                      marker=marker,
                                                      want_objects=True)
+            for instance in instance_list:
+                instance_obj.add_image_ref(context, instance)
         except exception.MarkerNotFound:
             msg = _('marker [%s] not found') % marker
             raise exc.HTTPBadRequest(explanation=msg)
@@ -766,7 +769,8 @@ class Controller(wsgi.Controller):
             context = req.environ['nova.context']
             instance = self.compute_api.get(context, id,
                                             want_objects=True)
-            req.cache_db_instance(instance)
+            req.cache_db_instance(instance_obj.add_image_ref(context,
+                                                             instance))
             return self._view_builder.show(req, instance)
         except exception.NotFound:
             msg = _("Instance could not be found")

nova/objects/instance.py

@@ -14,6 +14,7 @@
 
 from nova.cells import opts as cells_opts
 from nova.cells import rpcapi as cells_rpcapi
+from nova import compute
 from nova.compute import flavors
 from nova import db
 from nova import exception
@@ -567,6 +568,20 @@ class Instance(base.NovaPersistentObject, base.NovaObject):
             self.obj_reset_changes(['metadata'])
 
 
+def add_image_ref(context, instance):
+    """Helper method to add image_ref to instance object."""
+    if not instance['image_ref']:
+        compute_api = compute.API()
+        bdms = objects.BlockDeviceMappingList.get_by_instance_uuid(
+                context, instance['uuid'])
+        if compute_api.is_volume_backed_instance(context, instance, bdms):
+            props = bdms.root_metadata(
+                    context, compute_api.image_api,
+                    compute_api.volume_api)
+            instance['image_ref'] = props['image_id']
+    return instance
+
+
 def _make_instance_list(context, inst_list, db_inst_list, expected_attrs):
     get_fault = expected_attrs and 'fault' in expected_attrs
     inst_faults = {}

nova/tests/api/openstack/compute/test_servers.py

@@ -196,6 +196,8 @@ class ServersControllerTest(ControllerTest):
 
     def setUp(self):
         super(ServersControllerTest, self).setUp()
+        self.compute_api = self.controller.compute_api
+        self.context = context.RequestContext('fake', 'fake')
 
     def test_can_check_loaded_extensions(self):
         self.ext_mgr.extensions = {'os-fake': None}
@@ -259,6 +261,25 @@ class ServersControllerTest(ControllerTest):
         res_dict = self.controller.show(req, FAKE_UUID)
         self.assertEqual(res_dict['server']['id'], FAKE_UUID)
 
+    def test_get_server_no_image(self):
+
+        def return_instance(self, *args, **kwargs):
+            return fakes.stub_instance(id=1, uuid=FAKE_UUID,
+                                       project_id=str(uuid.uuid4()),
+                                       image_ref='')
+
+        def fake_add_image_ref(context, instance):
+            instance['image_ref'] = 'fake_image'
+            return instance
+
+        self.stubs.Set(db, 'instance_get_by_uuid', return_instance)
+        self.stubs.Set(instance_obj, 'add_image_ref', fake_add_image_ref)
+
+        req = fakes.HTTPRequest.blank('/fake/servers/%s' % FAKE_UUID)
+        server = self.controller.show(req, FAKE_UUID)
+
+        self.assertEqual('fake_image', server['server']['image']['id'])
+
     def test_unique_host_id(self):
         """Create two servers with the same host and different
            project_ids and check that the hostId's are unique.
@@ -517,6 +538,29 @@ class ServersControllerTest(ControllerTest):
 
             self.assertEqual(s['links'], expected_links)
 
+    def test_get_servers_no_image(self):
+
+        def fake_get_all(compute_self, context, search_opts=None,
+                         sort_key=None, sort_dir='desc',
+                         limit=None, marker=None, want_objects=False):
+            db_list = [fakes.stub_instance(100,
+                                           uuid=FAKE_UUID,
+                                           image_ref='')]
+            return instance_obj._make_instance_list(
+                context, objects.InstanceList(), db_list, FIELDS)
+
+        def fake_add_image_ref(context, instance):
+            instance['image_ref'] = 'fake_image'
+            return instance
+
+        self.stubs.Set(instance_obj, 'add_image_ref', fake_add_image_ref)
+        self.stubs.Set(compute_api.API, 'get_all', fake_get_all)
+
+        req = fakes.HTTPRequest.blank('/fake/servers/detail')
+        res_dict = self.controller.detail(req)
+        for s in res_dict['servers']:
+            self.assertEqual('fake_image', s['image']['id'])
+
     def test_get_servers_with_limit(self):
         req = fakes.HTTPRequest.blank('/fake/servers?limit=3')
         res_dict = self.controller.index(req)

nova/tests/objects/test_instance.py

@@ -21,6 +21,7 @@ import netaddr
 
 from nova.cells import rpcapi as cells_rpcapi
 from nova.compute import flavors
+from nova import context
 from nova import db
 from nova import exception
 from nova.network import model as network_model
@@ -1088,3 +1089,14 @@ class TestInstanceObjectMisc(test.NoDBTestCase):
         self.stubs.Set(instance, '_INSTANCE_OPTIONAL_JOINED_FIELDS', ['bar'])
         self.assertEqual(['bar'], instance._expected_cols(['foo', 'bar']))
         self.assertIsNone(instance._expected_cols(None))
+
+
+class TestAddImageRef(test.TestCase):
+    @mock.patch('nova.objects.BlockDeviceMappingList.root_metadata')
+    def test_add_image_ref(self, mock_root_metadata):
+        mock_root_metadata.return_value = {'image_id': 'fake_image'}
+        fake_instance = fakes.stub_instance(id=1, uuid=fakes.FAKE_UUID,
+                                            image_ref='')
+        ctx = context.RequestContext('fake-user', 'fake-project')
+        new_instance = instance.add_image_ref(ctx, fake_instance)
+        self.assertEqual('fake_image', new_instance['image_ref'])