Only get image location attributes if including locations

Commit 155eeabbfa added 'direct_url' and
'locations' to the list of attributes to get from an image which makes a
call back to glance if the attributes aren't on the image, and can
result in a 404 if they aren't available, which would be in the glance
v1 API case.

This change simply passes the new include_locations parameter down to
_extract_attributes so we can do the proper filtering.

Change-Id: I903fa5c781fed52183b340dc3d9bc4b6598b21ce
Partial-Bug: #1351333

nova/image/glance.py

@@ -307,16 +307,14 @@ class GlanceImageService(object):
         if not _is_image_available(context, image):
             raise exception.ImageNotFound(image_id=image_id)
 
-        image = _translate_from_glance(image)
+        image = _translate_from_glance(image,
+                                       include_locations=include_locations)
         if include_locations:
             locations = image.get('locations', None) or []
             du = image.get('direct_url', None)
             if du:
                 locations.append({'url': du, 'metadata': {}})
             image['locations'] = locations
-        else:
-            image.pop('locations', None)
-            image.pop('direct_url', None)
 
         return image
 
@@ -482,8 +480,9 @@ def _translate_to_glance(image_meta):
     return image_meta
 
 
-def _translate_from_glance(image):
-    image_meta = _extract_attributes(image)
+def _translate_from_glance(image, include_locations=False):
+    image_meta = _extract_attributes(image,
+                                     include_locations=include_locations)
     image_meta = _convert_timestamps_to_datetimes(image_meta)
     image_meta = _convert_from_string(image_meta)
     return image_meta
@@ -532,7 +531,7 @@ def _convert_to_string(metadata):
     return _convert(_json_dumps, metadata)
 
 
-def _extract_attributes(image):
+def _extract_attributes(image, include_locations=False):
     # NOTE(hdd): If a key is not found, base.Resource.__getattr__() may perform
     # a get(), resulting in a useless request back to glance. This list is
     # therefore sorted, with dependent attributes as the end
@@ -547,6 +546,7 @@ def _extract_attributes(image):
 
     queued = getattr(image, 'status') == 'queued'
     queued_exclude_attrs = ['disk_format', 'container_format']
+    include_locations_attrs = ['direct_url', 'locations']
     output = {}
 
     for attr in IMAGE_ATTRIBUTES:
@@ -560,6 +560,10 @@ def _extract_attributes(image):
         # NOTE(liusheng): queued image may not have these attributes and 'name'
         elif queued and attr in queued_exclude_attrs:
             output[attr] = getattr(image, attr, None)
+        # NOTE(mriedem): Only get location attrs if including locations.
+        elif attr in include_locations_attrs:
+            if include_locations:
+                output[attr] = getattr(image, attr, None)
         else:
             # NOTE(xarses): Anything that is caught with the default value
             # will result in a additional lookup to glance for said attr.

nova/tests/image/test_glance.py

@@ -454,7 +454,7 @@ class TestGlanceImageService(test.NoDBTestCase):
         self.assertEqual(same_id, image_id)
         self.assertEqual(service._client.host, 'something-less-likely')
 
-    def test_extracting_missing_attributes(self):
+    def _test_extracting_missing_attributes(self, include_locations):
         """Verify behavior from glance objects that are missing attributes
 
         This fakes the image class and is missing attribute as the client can
@@ -475,7 +475,8 @@ class TestGlanceImageService(test.NoDBTestCase):
             'updated_at': self.NOW_DATETIME,
         }
         image = MyFakeGlanceImage(metadata)
-        observed = glance._extract_attributes(image)
+        observed = glance._extract_attributes(
+            image, include_locations=include_locations)
         expected = {
             'id': 1,
             'name': None,
@@ -492,12 +493,19 @@ class TestGlanceImageService(test.NoDBTestCase):
             'deleted': None,
             'status': None,
             'properties': {},
-            'owner': None,
-            'locations': None,
-            'direct_url': None
+            'owner': None
         }
+        if include_locations:
+            expected['locations'] = None
+            expected['direct_url'] = None
         self.assertEqual(expected, observed)
 
+    def test_extracting_missing_attributes_include_locations(self):
+        self._test_extracting_missing_attributes(include_locations=True)
+
+    def test_extracting_missing_attributes_exclude_locations(self):
+        self._test_extracting_missing_attributes(include_locations=False)
+
 
 def _create_failing_glance_client(info):
     class MyGlanceStubClient(glance_stubs.StubGlanceClient):
@@ -652,7 +660,7 @@ class TestShow(test.NoDBTestCase):
         client.call.assert_called_once_with(ctx, 1, 'get',
                                             mock.sentinel.image_id)
         is_avail_mock.assert_called_once_with(ctx, {})
-        trans_from_mock.assert_called_once_with({})
+        trans_from_mock.assert_called_once_with({}, include_locations=False)
         self.assertIn('mock', info)
         self.assertEqual(mock.sentinel.trans_from, info['mock'])
 
@@ -743,7 +751,8 @@ class TestShow(test.NoDBTestCase):
 
         client.call.assert_called_once_with(ctx, 2, 'get', image_id)
         avail_mock.assert_called_once_with(ctx, mock.sentinel.image)
-        trans_from_mock.assert_called_once_with(mock.sentinel.image)
+        trans_from_mock.assert_called_once_with(mock.sentinel.image,
+                                                include_locations=True)
         self.assertIn('locations', info)
         self.assertEqual(locations, info['locations'])