安装好mysql 8.0后，查看初始密码：

sudo grep 'temporary password' /var/log/mysqld.log

本地MySQL客户端登录：mysql -uroot -p ，输入默认密码进去，如果不修改默认密码，操作执行命令会报错如下：

You must reset your password using ALTER USER statement before executing this statement.

修改密码

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '*{your-password}*';