一、设置密码

1.需要在配置文件中开启x-pack验证, 修改config目录下面的elasticsearch.yml文件，在里面添加如下内容,并重启.

xpack.security.enabled: true
xpack.license.self_generated.type: basic
xpack.security.transport.ssl.enabled: true

2，执行设置用户名和密码的命令,这里需要为4个用户分别设置密码，elastic, kibana, logstash_system,beats_system

bin/elasticsearch-setup-passwords interactive

网上设置时出现的：

Initiating the setup of passwords for reserved users elastic,kibana,logstash_system,beats_system.
You will be prompted to enter passwords as the process progresses.
Please confirm that you would like to continue [y/N]y
Enter password for [elastic]: 
passwords must be at least [6] characters long
Try again.
Enter password for [elastic]: 
Reenter password for [elastic]: 
Passwords do not match.
Try again.
Enter password for [elastic]: 
Reenter password for [elastic]: 
Enter password for [kibana]: 
Reenter password for [kibana]: 
Enter password for [logstash_system]: 
Reenter password for [logstash_system]: 
Enter password for [beats_system]: 
Reenter password for [beats_system]: 
Changed password for user [kibana]
Changed password for user [logstash_system]
Changed password for user [beats_system]
Changed password for user [elastic]

我设置密码时出现的：

[es@k8snode2 elasticsearch-7.3.0]$ ./bin/elasticsearch-setup-passwords interactive
Initiating the setup of passwords for reserved users elastic,apm_system,kibana,logstash_system,beats_system,remote_monitoring_user.
You will be prompted to enter passwords as the process progresses.
Please confirm that you would like to continue [y/N]y


Enter password for [elastic]: 
Reenter password for [elastic]: 
Passwords do not match.
Try again.
Enter password for [elastic]: 
Reenter password for [elastic]: 
Enter password for [apm_system]: 
Reenter password for [apm_system]: 
Enter password for [kibana]: 
Reenter password for [kibana]: 
Enter password for [logstash_system]: 
Reenter password for [logstash_system]: 
Enter password for [beats_system]: 
Reenter password for [beats_system]: 
Enter password for [remote_monitoring_user]: 
Reenter password for [remote_monitoring_user]: 
Changed password for user [apm_system]
Changed password for user [kibana]
Changed password for user [logstash_system]
Changed password for user [beats_system]
Changed password for user [remote_monitoring_user]
Changed password for user [elastic]

其中，用户权限分别如下：

• elastic 账号：拥有 superuser 角色，是内置的超级用户。
• kibana 账号：拥有 kibana_system 角色，用户 kibana 用来连接 elasticsearch 并与之通信。Kibana 服务器以该用户身份提交请求以访问集群监视 API 和 .kibana 索引。不能访问 index。
• logstash_system 账号：拥有 logstash_system 角色。用户 Logstash 在 Elasticsearch 中存储监控信息时使用。

二、修改密码

修改密码命令如下：

curl -H "Content-Type:application/json" -XPOST -u elastic 'http://127.0.0.1:9200/_xpack/security/user/elastic/_password' -d '{ "password" : "123456" }'

三、带密码查询

Elasticsearch设置用户名密码之后，不能再直接使用Elasticsearch head 访问，可以在查询等API上加上用户等参数：

curl -XGET --user user:passwd 'http://XXXX:9200/XX/XXX'

比如想要清空某个索引下的数据：

 curl -XPOST  --user admin:admin 'http://XXXX:9200/XXXX/XXX/_delete_by_query'  -H "Content-Type: application/json" -d '{ "query":{"match_all":{}}}'

四、添加自定义角色

添加角色接口为：POST /_xpack/security/role/

下面添加一个超级管理员角色为例：

[elastic@data-backup elasticsearch-6.2.4]$ curl -XPOST -H 'Content-type: application/json' -u elastic:elastic123 'http://10.163.19.231:9600/_xpack/security/role/admin?pretty' -d '{
"run_as":["elastic"],
"cluster":["all"],
"indices":[
 {
  "names":["*"],
  "privileges":["all"]
 }
]
}'
{
 "role" : {
 "created" : true
 }
}
[elastic@data-backup elasticsearch-6.2.4]$ curl -XGET -H 'Content-type: application/json' -u elastic:elastic123 'http://10.163.19.231:9600/_xpack/security/role/admin?pretty'
{
  "admin" : {
  "cluster" : [
   "all"
  ],
  "indices" : [
   {
     "names" : [
      "*"
     ],
     "privileges" : [
      "all"
     ]
    }
   ],
   "run_as" : [
    "elastic"
   ],
   "metadata" : { },
   "transient_metadata" : {
    "enabled" : true
  }
 }
}

五、添加自定义用户

添加用户接口为：POST/_xpack/security/user/

下面以添加一个test用户并添加至admin角色为例：

[elastic@data-backup elasticsearch-6.2.4]$ curl -XGET -H 'Content-type: application/json' -u test:Test123654% 'http://10.163.19.231:9600/_cat/indices?pretty'
green  open .monitoring-es-6-2019.09.17   J1K2XG1eTXqw0GHSOH5Gwg 1 0     848    104 846.9kb 846.9kb
green  open .watches                      qHj5owowRC-3DeK8DaLD-g 1 0       6      0  47.8kb  47.8kb
green  open .triggered_watches            2pm3BwCnTaKgyzl39eFpUw 1 0       0      0   5.1kb   5.1kb
yellow open monitor                       yFnfztziSguTq9VsfSANpw 5 1      48      0 226.7kb 226.7kb
green  open .watcher-history-7-2019.09.17 uz6RA_8vRraHHLAitWKtAw 1 0      74      0 259.8kb 259.8kb
green  open .monitoring-alerts-6          ZPTqnNVOQ5GlUK1ncXNQDQ 1 0       2      0  18.1kb  18.1kb
yellow open track                         AqSGAZnAQE2NGvZXlp9zcw 5 1 1343729 175384   201mb   201mb
green  open .security-6                   83fAslPbQDSGbGWfhiMAXA 1 0

注：这里要注意的是用户密码最好不要有"$" "!"之类的字符，这样有可能会导致密码认证不成功，其他字符测试过暂时没问题（具体原因不详，反正我遇到过这个坑）

六、header带密码插件访问

修改配置文件elasticsearch.yml，增加
http.cors.allow-headers: Authorization

访问head时，url如下所示：
http://192.168.100.100:9100/auth_user=elastic&auth_password=changeme

七、java api带密码访问

//初始化ES操作客户端
        final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
        credentialsProvider.setCredentials(AuthScope.ANY,
                new UsernamePasswordCredentials("elastic", "123456"));  //es账号密码（默认用户名为elastic）
        RestHighLevelClient esClient =new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("127.0.0.1",9200)
                ).setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback() {
                    public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpClientBuilder) {
                        httpClientBuilder.disableAuthCaching();
                        return httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider);
                    }
                })/.setMaxRetryTimeoutMillis(2000)/
        );