环境

服务器：centos6
操作系统：win7
工具：CRT
elasticsearch：6.0.0

命令

[yutao@master01 elasticsearch-6.0.0]$ bin/x-pack/setup-passwords auto
Initiating the setup of reserved user elastic,kibana,logstash_system passwords.
The passwords will be randomly generated and printed to the console.
Please confirm that you would like to continue [y/N]y


Changed password for user kibana
PASSWORD kibana = WjFJ6G$lEH71W7K1+vcl

Changed password for user logstash_system
PASSWORD logstash_system = TS8ZR41smxm9o?F6gbBB

Changed password for user elastic
PASSWORD elastic = rc~ENBxy?18hOQ^R9OUJ

[yutao@master01 elasticsearch-6.0.0]$

也就是：

bin/x-pack/setup-passwords auto

如果想自己来指定密码的话，执行：

bin/x-pack/setup-passwords interactive

会有交互，让你输入密码；

Setting Built-in User Passwords

Getting Started with Security