docker安装elasticsearch 5.2.1 x-pack 无法登陆

大神们好：
首先我描述下我的安装环境
1)我配置了3个节点使用3个docker容器

2)安装完后集群运行正常了

3)我登录其中一个节点所在的容器（bash）安装了x-pack插件，然后重启了这个容器

4)我尝试使用如下这个url登录es:
http://192.168.21.21:9200/_cat/health?v
但是一直提示登录，无线重复，点击取消后返回的结果是:
{"error":{"root_cause":[{"type":"security_exception","reason":"failed to authenticate user [elastic]","header":{"WWW-Authenticate":"Basic realm=\"security\" charset=\"UTF-8\""}}],"type":"security_exception","reason":"failed to authenticate user [elastic]","header":{"WWW-Authenticate":"Basic realm=\"security\" charset=\"UTF-8\""}},"status":401}

5)然后没辙，我使用url请求尝试修改其中一个用户的密码，但是返回的结果跟第4步类似:
curl -XPUT -u elastic '192.168.21.21:9200/_xpack/security/user/elastic/_password' -d '{
"password" : "elasticpassword"
}'
**

{"error":{"root_cause":[{"type":"security_exception","reason":"failed to authenticate user [elastic]","header":{"WWW-Authenticate":"Basic realm=\"security\" charset=\"UTF-8\""}}],"type":"security_exception","reason":"failed to authenticate user [elastic]","header":{"WWW-Authenticate":"Basic realm=\"security\" charset=\"UTF-8\""}},"status":401}
最后没辙，我尝试使用es社区关于安全这块的步骤配置了一遍，结果还是一样
https://www.elastic.co/guide/e ... .html

希望各位大神能给予指点，谢谢！