log/log.go
func Fatalf(format string, args ...interface{}) {
	logger.Output(2, LevelFatal, fmt.Sprintf(format, args...))
	os.Exit(1)
}
func Fatalf(format string, args ...interface{}) {
	logger.Output(2, LevelFatal, fmt.Sprintf(format, args...))
	os.Exit(1)
}
// Fatalf records the log with fatal level and exits