官方文档：https://www.elastic.co/guide/en/elasticsearch/reference/8.1/security-basic-setup.html

其他参考资料：
https://blog.csdn.net/qq330983778/article/details/103537252
https://blog.csdn.net/wzh8108/article/details/105202077
https://blog.csdn.net/qq_27639777/article/details/98470844