[root@localhost116 mysql]# tail -100f /var/log/mysqld.log
2019-04-25T04:30:51.315933Z 0 [System] [MY-013169] [Server] /usr/sbin/mysqld (mysqld 8.0.15) initializing of server in progress as process 25808
2019-04-25T04:30:55.323029Z 5 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: fu#0YkCp)uv8
2019-04-25T04:30:57.526215Z 0 [System] [MY-013170] [Server] /usr/sbin/mysqld (mysqld 8.0.15) initializing of server has completed
2019-04-25T04:30:59.986257Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.15) starting as process 26049
2019-04-25T04:31:00.635553Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2019-04-25T04:31:00.667243Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.15'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  MySQL Community Server - GPL.
2019-04-25T04:31:00.765178Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Socket: '/var/run/mysqld/mysqlx.sock' bind-address: '::' port: 33060

[root@localhost107 mysql]# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 10
Server version: 8.0.15Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql>

[root@localhost107 mysql]# service mysqld restart
停止 mysqld： [确定]
正在启动 mysqld： [确定]
[root@localhost107 mysql]#

show variables like '%auth%';    #查看 default_authentication_plugin 的值
show variables like 'default_password_lifetime';    #查看 default_password_lifetime 的值
show variables like '%pass%';   #查看模糊查询pass 属性的值
select user,host,plugin from mysql.user;   #查看user表相关字段
set global validate_password_policy=0;      #设置 validate_password_policy 全局值为0，可不遵循密码规则
set global validate_password_length=4;   #设置 validate_password_length 密码长度最少位数
flush privileges;   #修改生效
create user 用户名 identified by '密码';  #新增用户及密码
grant all on *.* to 用户名;    #给用户授权所有权限

mysql> set global validate_password_policy=0;
ERROR 1193 (HY000): Unknown system variable 'validate_password_policy'