LeftHand Fix terminate_connection when failed over

Terminate connection will fail when a detach is called on a failed
over volume. This patch allows terminate_connection to succeed in
order to allow reattachments to secondary arrays.

Change-Id: I9057f1c5d6e5716a6283c3b08ddad7bfe4904234
Closes-Bug: #1580693
(cherry picked from commit 6ab5e5234b)

cinder/tests/unit/test_hpelefthand.py

@@ -617,6 +617,28 @@ class TestHPELeftHandISCSIDriver(HPELeftHandBaseDriver, test.TestCase):
                 self.volume,
                 self.connector)
 
+    def test_terminate_connection_from_primary_when_failed_over(self):
+        # setup drive with default configuration
+        # and return the mock HTTP LeftHand client
+        mock_client = self.setup_driver()
+
+        mock_client.getServerByName.side_effect = hpeexceptions.HTTPNotFound(
+            "The host does not exist.")
+
+        with mock.patch.object(hpe_lefthand_iscsi.HPELeftHandISCSIDriver,
+                               '_create_client') as mock_do_setup:
+            mock_do_setup.return_value = mock_client
+
+            self.driver._active_backend_id = 'some_id'
+            # execute terminate_connection
+            self.driver.terminate_connection(self.volume, self.connector)
+
+            # When the volume is still attached to the primary array after a
+            # fail-over, there should be no call to delete the server.
+            # We can assert this method is not called to make sure
+            # the proper exceptions are being raised.
+            self.assertEqual(0, mock_client.removeServerAccess.call_count)
+
     def test_terminate_connection_multiple_volumes_on_server(self):
 
         # setup drive with default configuration

cinder/volume/drivers/hpe/hpe_lefthand_iscsi.py

@@ -152,9 +152,10 @@ class HPELeftHandISCSIDriver(driver.ISCSIDriver):
         2.0.6 - Update replication to version 2.1
         2.0.7 - Fixed bug #1554746, Create clone volume with new size.
         2.0.8 - Add defaults for creating a replication client, bug #1556331
+        2.0.9 - Fix terminate connection on failover
     """
 
-    VERSION = "2.0.8"
+    VERSION = "2.0.9"
 
     device_stats = {}
 
@@ -744,6 +745,22 @@ class HPELeftHandISCSIDriver(driver.ISCSIDriver):
 
             if removeServer:
                 client.deleteServer(server_info['id'])
+        except hpeexceptions.HTTPNotFound as ex:
+            # If a host is failed-over, we want to allow the detach to
+            # to 'succeed' when it cannot find the host. We can simply
+            # return out of the terminate connection in order for things
+            # to be updated correctly.
+            if self._active_backend_id:
+                LOG.warning(_LW("Because the host is currently in a "
+                                "failed-over state, the volume will not "
+                                "be properly detached from the primary "
+                                "array. The detach will be considered a "
+                                "success as far as Cinder is concerned. "
+                                "The volume can now be attached to the "
+                                "secondary target."))
+                return
+            else:
+                raise exception.VolumeBackendAPIException(ex)
         except Exception as ex:
             raise exception.VolumeBackendAPIException(ex)
         finally: