mysql8 linux安装教程

#下载rpm捆绑包
wget https://cdn.mysql.com//Downloads/MySQL-8.0/mysql-8.0.28-1.el7.x86_64.rpm-bundle.tar
 
#卸载centos自带的mariadb
rpm -qa |grep mariadb #查看
rpm -e mariadb-libs-5.5.64-1.el7.x86_64  #如果卸载不掉，则用yum卸载
yum -y remove mariadb-libs-5.5.64-1.el7.x86_64

#卸载旧版本的mysql, 卸载命令同上
rpm -qa |grep mysql #查看

#若存在原先装过旧版的mysql, 需解锁以下文件
chattr -ia /etc/passwd /etc/group /etc/shadow /etc/gshadow
 
#解压捆绑包
tar -xvf mysql-8.0.28-1.el7.x86_64.rpm-bundle.tar
# 按顺序安装包
rpm -ivh mysql-community-common-8.0.28-1.el7.x86_64.rpm
rpm -ivh mysql-community-client-plugins-8.0.28-1.el7.x86_64.rpm
rpm -ivh mysql-community-libs-8.0.28-1.el7.x86_64.rpm
rpm -ivh mysql-community-client-8.0.28-1.el7.x86_64.rpm
rpm -ivh mysql-community-icu-data-files-8.0.28-1.el7.x86_64.rpm
rpm -ivh mysql-community-server-8.0.28-1.el7.x86_64.rpm
 
#vim /etc/my.cnf
#修改目录和配置文件
 
#启动
systemctl start mysqld #启动
systemctl enable mysqld #开机启动
#查看
mysqladmin --version #或者 mysql --version

#若存在原先装过旧版的mysql, 再给以下文件上锁
chattr +ia /etc/passwd /etc/group /etc/shadow /etc/gshadow

#获取默认随机密码
grep password /cache1/mysql/mysqld.log
 
#登录mysql
mysql -uroot -p #登录数据库执行以下命令
 
#修改密码规则（不建议）
set global validate_password.policy=0;#密码复杂度,分为low(0)、medium(1)、high(2)三个等级，默认为midium（1）
set global validate_password.length=1;
 
#查看参数值
select @@validate_password.policy;
 
#修改密码
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '****';
#mysql8 之前，默认加密规则是mysql_native_password；
#mysql8 之后，默认加密规则是caching_sha2_password；
 
#设置远程登录, root账号建议禁止远程登录
use mysql;
update user set host='%' where user ='root';
flush privileges;
exit;
#重启服务
systemctl restart mysqld.service #重启

另外, 如果机器上安装了keepalived服务, 须注意安装mysql可能会导致keepalived被卸载掉, 因为keepalived依赖着mariadb