在Elasticsearch7.X，x-pack已经作为默认的插件集成在Elasticsearch里面了，所以无需在bin/elasticsearch-plugin install x-pack了，直接在配置文件中启用就可以了
[root@localhost bin]# ./elasticsearch-plugin install x-pack
ERROR: this distribution of Elasticsearch contains X-Pack by default开启x-pack
参考官方文档，开启x-pack只需要在elasticsearch的配置文件elasticsearch.yml文件中新增如下配置即可：
# 开启x-pack安全验证
# 配置X-Pack
http.cors.enabled: true
http.cors.allow-origin: "*"
http.cors.allow-headers: Authorization
xpack.security.enabled: true
xpack.security.audit.enabled: true
xpack.license.self_generated.type: basic
# 如果是basic license的话需要加入下面这一行，不然的话restart elasticsearch之后会报错。
xpack.security.transport.ssl.enabled: true
设置密码
[root@host-172-16-200-6 bin]# ./elasticsearch-setup-passwords interactive
warning: usage of JAVA_HOME is deprecated, use ES_JAVA_HOME
Future versions of Elasticsearch will require Java 11; your Java version from [/usr/jdk1.8.0_241/jre] does not meet this requirement. Consider switching to a distribution of Elasticsearch with a bundled JDK. If you are already using a distribution with a bundled JDK, ensure the JAVA_HOME environment variable is not set.
Initiating the setup of passwords for reserved users elastic,apm_system,kibana,kibana_system,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]:
Enter password for [apm_system]:
Reenter password for [apm_system]:
Enter password for [kibana_system]:
Reenter password for [kibana_system]:
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_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]
密码设置完成后需要在相对应的服务中增加elasticsearch的账号密码，例如kibana、logstash。 kibana设置：
elasticsearch.username: "elastic"
elasticsearch.password: "123456"