Add user message when share shrinking fails at the driver

Not all drivers support share shrinking.
This patch adds a user message when shrinking fails due to operation
not being supported.

Change-Id: I5137cd972ec7737d70865038d7b82cfe13b9566c
Closes-Bug: #1802424

manila/message/message_field.py

@@ -94,6 +94,10 @@ class Detail(object):
           " smaller than the current used space. The share status has been"
           " set to available. Please select a size greater than the current"
           " used space."))
+    DRIVER_FAILED_SHRINK = (
+        '019',
+        _("Share Driver does not support shrinking shares."
+          " Shrinking share operation failed."))
 
     ALL = (UNKNOWN_ERROR,
            NO_VALID_HOST,
@@ -112,7 +116,8 @@ class Detail(object):
            DRIVER_FAILED_EXTEND,
            FILTER_CREATE_FROM_SNAPSHOT,
            DRIVER_FAILED_CREATING_FROM_SNAP,
-           DRIVER_REFUSED_SHRINK)
+           DRIVER_REFUSED_SHRINK,
+           DRIVER_FAILED_SHRINK)
 
     # Exception and detail mappings
     EXCEPTION_DETAIL_MAPPINGS = {

manila/share/manager.py

@@ -3945,6 +3945,16 @@ class ShareManager(manager.SchedulerDependentManager):
                                        share_instance, "shrink.start")
 
         def error_occurred(exc, msg, status=constants.STATUS_SHRINKING_ERROR):
+            if isinstance(exc, NotImplementedError):
+                msg = _("Shrink share operation not supported.")
+                status = constants.STATUS_AVAILABLE
+                self.message_api.create(
+                    context,
+                    message_field.Action.SHRINK,
+                    share['project_id'],
+                    resource_type=message_field.Resource.SHARE,
+                    resource_id=share['id'],
+                    detail=message_field.Detail.DRIVER_FAILED_SHRINK)
             LOG.exception(msg, resource=share)
             self.db.share_update(context, share['id'], {'status': status})
 

manila/tests/share/test_manager.py

@@ -3681,6 +3681,52 @@ class ShareManagerTestCase(test.TestCase):
                                   (['INFO', 'share.extend.start'],
                                    ['INFO', 'share.extend.end']))
 
+    def test_shrink_share_not_supported(self):
+        share = db_utils.create_share(size=2)
+        new_size = 1
+        share_id = share['id']
+
+        self.mock_object(self.share_manager.db, 'share_get',
+                         mock.Mock(return_value=share))
+        self.mock_object(self.share_manager, 'driver')
+        self.mock_object(self.share_manager.db, 'share_update')
+
+        self.mock_object(quota.QUOTAS, 'reserve')
+        self.mock_object(quota.QUOTAS, 'rollback')
+        self.mock_object(self.share_manager.driver, 'shrink_share',
+                         mock.Mock(side_effect=NotImplementedError))
+
+        self.assertRaises(
+            exception.ShareShrinkingError,
+            self.share_manager.shrink_share, self.context, share_id, new_size)
+
+        self.share_manager.driver.shrink_share.assert_called_once_with(
+            utils.IsAMatcher(models.ShareInstance),
+            new_size, share_server=None
+        )
+
+        self.share_manager.db.share_update.assert_called_once_with(
+            mock.ANY, share_id, {'status': constants.STATUS_AVAILABLE}
+        )
+
+        quota.QUOTAS.reserve.assert_called_once_with(
+            mock.ANY, gigabytes=-1, project_id=share['project_id'],
+            share_type_id=None, user_id=share['user_id'],
+        )
+        quota.QUOTAS.rollback.assert_called_once_with(
+            mock.ANY, mock.ANY, project_id=share['project_id'],
+            share_type_id=None, user_id=share['user_id'],
+        )
+        self.assertTrue(self.share_manager.db.share_get.called)
+
+        self.share_manager.message_api.create.assert_called_once_with(
+            utils.IsAMatcher(context.RequestContext),
+            message_field.Action.SHRINK,
+            share['project_id'],
+            resource_type=message_field.Resource.SHARE,
+            resource_id=share_id,
+            detail=message_field.Detail.DRIVER_FAILED_SHRINK)
+
     @ddt.data((True, [{'id': 'fake'}]), (False, []))
     @ddt.unpack
     def test_shrink_share_quota_error(self, supports_replication,

releasenotes/notes/bug-1802424-add-user-message-when-shrinking-fails-83d0f60ead6f4a4b.yaml

@@ -0,0 +1,5 @@
+
+fixes:
+  - |
+    Added a new user message when share shrinking fails due to operation not being
+    supported by the driver.