Add support for getting volume details with a specified microversion

This allows us to get volume details and pass through a microversion.
This will be used to get a volume with microversion 3.48 where
the shared_targets and service_uuid parameters are in the response.
We will then use that information to determine if we should lock
attach/detach operations on that volume.

Part of blueprint multi-attach-volume

Change-Id: Ief30adfef35eefe03e5a3d3d9623cd48e4d334a4

nova/tests/unit/volume/test_cinder.py

@@ -117,7 +117,7 @@ class CinderApiTestCase(test.NoDBTestCase):
 
         self.api.get(self.ctx, volume_id)
 
-        mock_cinderclient.assert_called_once_with(self.ctx)
+        mock_cinderclient.assert_called_once_with(self.ctx, microversion=None)
         mock_volumes.get.assert_called_once_with(volume_id)
 
     @mock.patch('nova.volume.cinder.cinderclient')
@@ -144,6 +144,35 @@ class CinderApiTestCase(test.NoDBTestCase):
         self.assertRaises(exception.CinderConnectionFailed,
                   self.api.get, self.ctx, 'id1')
 
+    @mock.patch('nova.volume.cinder.cinderclient')
+    def test_get_with_shared_targets(self, mock_cinderclient):
+        """Tests getting a volume at microversion 3.48 which includes the
+        shared_targets and service_uuid parameters in the volume response body.
+        """
+        mock_volume = mock.MagicMock(
+            shared_targets=False, service_uuid=uuids.service_uuid)
+        mock_volumes = mock.MagicMock()
+        mock_volumes.get.return_value = mock_volume
+        mock_cinderclient.return_value = mock.MagicMock(volumes=mock_volumes)
+        vol = self.api.get(self.ctx, uuids.volume_id, microversion='3.48')
+        mock_cinderclient.assert_called_once_with(
+            self.ctx, microversion='3.48')
+        mock_volumes.get.assert_called_once_with(uuids.volume_id)
+        self.assertIn('shared_targets', vol)
+        self.assertFalse(vol['shared_targets'])
+        self.assertEqual(uuids.service_uuid, vol['service_uuid'])
+
+    @mock.patch('nova.volume.cinder.cinderclient',
+                side_effect=exception.CinderAPIVersionNotAvailable(
+                    version='3.48'))
+    def test_get_microversion_not_supported(self, mock_cinderclient):
+        """Tests getting a volume at microversion 3.48 but that version
+        is not available.
+        """
+        self.assertRaises(exception.CinderAPIVersionNotAvailable,
+                          self.api.get, self.ctx, uuids.volume_id,
+                          microversion='3.48')
+
     @mock.patch('nova.volume.cinder.cinderclient')
     def test_create(self, mock_cinderclient):
         volume = FakeVolume('id1')
@@ -569,7 +598,7 @@ class CinderApiTestCase(test.NoDBTestCase):
 
         self.api.detach(self.ctx, 'id1', instance_uuid='fake_uuid')
 
-        mock_cinderclient.assert_called_with(self.ctx)
+        mock_cinderclient.assert_called_with(self.ctx, microversion=None)
         mock_volumes.detach.assert_called_once_with('id1', None)
 
     @mock.patch('nova.volume.cinder.cinderclient')
@@ -586,7 +615,7 @@ class CinderApiTestCase(test.NoDBTestCase):
 
         self.api.detach(self.ctx, 'id1', instance_uuid='fake_uuid')
 
-        mock_cinderclient.assert_called_with(self.ctx)
+        mock_cinderclient.assert_called_with(self.ctx, microversion=None)
         mock_volumes.detach.assert_called_once_with('id1', 'fakeid')
 
     @mock.patch('nova.volume.cinder.cinderclient')

nova/volume/cinder.py

@@ -199,6 +199,13 @@ def _untranslate_volume_summary_view(context, vol):
     if hasattr(vol, 'volume_image_metadata'):
         d['volume_image_metadata'] = copy.deepcopy(vol.volume_image_metadata)
 
+    # The 3.48 microversion exposes a shared_targets boolean and service_uuid
+    # string parameter which can be used with locks during volume attach
+    # and detach.
+    if hasattr(vol, 'shared_targets'):
+        d['shared_targets'] = vol.shared_targets
+        d['service_uuid'] = vol.service_uuid
+
     return d
 
 
@@ -332,8 +339,17 @@ class API(object):
     """API for interacting with the volume manager."""
 
     @translate_volume_exception
-    def get(self, context, volume_id):
-        item = cinderclient(context).volumes.get(volume_id)
+    def get(self, context, volume_id, microversion=None):
+        """Get the details about a volume given it's ID.
+
+        :param context: the nova request context
+        :param volume_id: the id of the volume to get
+        :param microversion: optional string microversion value
+        :raises: CinderAPIVersionNotAvailable if the specified microversion is
+            not available.
+        """
+        item = cinderclient(
+            context, microversion=microversion).volumes.get(volume_id)
         return _untranslate_volume_summary_view(context, item)
 
     @translate_cinder_exception