Merge "Avoid logging traceback when detach device not found"

Author: Zuul

nova/tests/unit/virt/libvirt/test_guest.py

@@ -327,6 +327,11 @@ def test_detach_device_with_retry_operation_failed(self, mock_detach):
             inc_sleep_time=.01, max_retry_count=3)
         # Some time later, we can do the wait/retry to ensure detach
         self.assertRaises(exception.DeviceNotFound, retry_detach)
+        # Check that the save_and_reraise_exception context manager didn't log
+        # a traceback when the libvirtError was caught and DeviceNotFound was
+        # raised.
+        self.assertNotIn('Original exception being dropped',
+                         self.stdlog.logger.output)
 
     @mock.patch.object(libvirt_guest.Guest, "detach_device")
     def test_detach_device_with_retry_operation_internal(self, mock_detach):

nova/virt/libvirt/guest.py

@@ -403,7 +403,7 @@ def _try_detach_device(conf, persistent=False, live=False):
                               device, persistent, live)
 
             except libvirt.libvirtError as ex:
-                with excutils.save_and_reraise_exception():
+                with excutils.save_and_reraise_exception(reraise=False) as ctx:
                     errcode = ex.get_error_code()
                     if errcode in (libvirt.VIR_ERR_OPERATION_FAILED,
                                    libvirt.VIR_ERR_INTERNAL_ERROR):
@@ -420,6 +420,10 @@ def _try_detach_device(conf, persistent=False, live=False):
                             # detach fails because the device is not found
                             raise exception.DeviceNotFound(
                                 device=alternative_device_name)
+                    # Re-raise the original exception if we're not raising
+                    # DeviceNotFound instead. This will avoid logging of a
+                    # "Original exception being dropped" traceback.
+                    ctx.reraise = True
 
         conf = get_device_conf_func(device)
         if conf is None: