下载rpm包
wget https://repo.mysql.com/mysql80-community-release-el7-3.noarch.rpm
安装mysql
rom -ivh mysql80-community-release-el7-3.noarch.rpm
安装mysql-community-server，如果安装不上，进入/etc/yum.repos.d看下是否有mysql安装源
yum -y install mysql-server
启动mysql
systemctl start mysqld
mysql安装后系统会生成一个默认的root密码，执行以下命令获取
grep 'temporary password' /var/log/mysqld.log
必须修改root密码后才能继续操作，修改root密码
mysql -u root -p
输入上面的临时密码
ALTER USER 'root'@'localhost' IDENTIFIED BY '新密码'
