Multi REST API calls error handling of "volume unset" command

Support multi REST API calls error handling for "volume unset"
command follow the rule in doc/source/command-errors.rst.
Also add a unit test for testing the error handling

Change-Id: I2de7a7bd5a7a5e39817ed5cf6952abf4afba75e4

openstackclient/tests/unit/volume/v2/test_volume.py

@@ -964,3 +964,30 @@ class TestVolumeUnset(TestVolume):
 
         self.volumes_mock.delete_image_metadata.assert_called_with(
             self.new_volume.id, parsed_args_unset.image_property)
+
+    def test_volume_unset_image_property_fail(self):
+        self.volumes_mock.delete_image_metadata.side_effect = (
+            exceptions.CommandError())
+        arglist = [
+            '--image-property', 'Alpha',
+            '--property', 'Beta',
+            self.new_volume.id,
+        ]
+        verifylist = [
+            ('image_property', ['Alpha']),
+            ('property', ['Beta']),
+            ('volume', self.new_volume.id),
+        ]
+        parsed_args = self.check_parser(
+            self.cmd_unset, arglist, verifylist)
+
+        try:
+            self.cmd_unset.take_action(parsed_args)
+            self.fail('CommandError should be raised.')
+        except exceptions.CommandError as e:
+            self.assertEqual('One or more of the unset operations failed',
+                             str(e))
+        self.volumes_mock.delete_image_metadata.assert_called_with(
+            self.new_volume.id, parsed_args.image_property)
+        self.volumes_mock.delete_metadata.assert_called_with(
+            self.new_volume.id, parsed_args.property)

openstackclient/volume/v2/volume.py

@@ -511,9 +511,23 @@ class UnsetVolume(command.Command):
         volume = utils.find_resource(
             volume_client.volumes, parsed_args.volume)
 
+        result = 0
         if parsed_args.property:
-            volume_client.volumes.delete_metadata(
+            try:
-                volume.id, parsed_args.property)
+                volume_client.volumes.delete_metadata(
+                    volume.id, parsed_args.property)
+            except Exception as e:
+                LOG.error(_("Failed to unset volume property: %s"), e)
+                result += 1
+
         if parsed_args.image_property:
-            volume_client.volumes.delete_image_metadata(
+            try:
-                volume.id, parsed_args.image_property)
+                volume_client.volumes.delete_image_metadata(
+                    volume.id, parsed_args.image_property)
+            except Exception as e:
+                LOG.error(_("Failed to unset image property: %s"), e)
+                result += 1
+
+        if result > 0:
+            raise exceptions.CommandError(_("One or more of the "
+                                          "unset operations failed"))