add retry for callback

server/workerManager.go

@@ -216,11 +216,14 @@ func (wm *WorkerManager) doCallback(hook string, response *odysseus.TaskResponse
 	} else {
 		log.WithField("task-id", response.TaskId).Debug("marshal task response")
 	}
+	for i := 0; i < 5; i++ {
 		err = utils.Post(hook, d)
 		if err != nil {
-		log.WithError(err).Error("post task result failed")
+			log.WithField("try", i).WithError(err).Error("post task result failed")
 		} else {
 			log.WithField("task-id", response.TaskId).Debug("post task result")
+			break
+		}
 	}
 }