看别人教程，又被坑了，自己记一下。
下载yum包
wget https://dev.mysql.com/get/mysql80-community-release-el7-1.noarch.rpm安装
sudo rpm -Uvh mysql80-community-release-el7-1.noarch.rpm安装server
yum install -y mysql-community-server启动
service mysqld start找临时密码
grep 'temporary password' /var/log/mysqld.log登陆
mysql -uroot -p改密码
set global validate_password.POLICY=0;
ALTER USER USER() IDENTIFIED BY '12345678'；授权其他机器登陆
To be continue...
忽然来个活。。。