1.查看centos系统版本

# cat /etc/redhat-release 
CentOS Linux release 7.9.2009 (Core)

2.下载并安装repo仓库文件

下载地址：https://dev.mysql.com/downloads/repo/yum/

# wget https://repo.mysql.com//mysql80-community-release-el7-5.noarch.rpm

# yum localinstall -y mysql80-community-release-el7-5.noarch.rpm 
已加载插件：fastestmirror
正在检查 mysql80-community-release-el7-5.noarch.rpm: mysql80-community-release-el7-5.noarch
mysql80-community-release-el7-5.noarch.rpm 将被安装
正在解决依赖关系
--> 正在检查事务
---> 软件包 mysql80-community-release.noarch.0.el7-5 将被 安装
--> 解决依赖关系完成

依赖关系解决

================================================================================================
 Package                     架构     版本      源                                         大小
================================================================================================
正在安装:
 mysql80-community-release   noarch   el7-5     /mysql80-community-release-el7-5.noarch   9.1 k

事务概要
================================================================================================
安装  1 软件包

总计：9.1 k
安装大小：9.1 k
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  正在安装    : mysql80-community-release-el7-5.noarch                                      1/1 
  验证中      : mysql80-community-release-el7-5.noarch                                      1/1 

已安装:
  mysql80-community-release.noarch 0:el7-5                                                      

完毕！

3.验证仓库软件

# yum makecache

# yum repolist all|grep mysql8
mysql80-community/x86_64            MySQL 8.0 Community Server      启用:    321
mysql80-community-source            MySQL 8.0 Community Server - So 禁用

# yum repolist enabled | grep "mysql*"            
mysql-connectors-community/x86_64       MySQL Connectors Community           230
mysql-tools-community/x86_64            MySQL Tools Community                138
mysql80-community/x86_64                MySQL 8.0 Community Server           321

4.安装MySQL8

说明：此时仓库中只有一个MySQL版本，因此可以直接安装

# yum install -y mysql-community-server

# 使用以下方式检查安装包
# rpm -qa|grep -i "mysql.*8.*"
mysql80-community-release-el7-5.noarch
mysql-community-client-plugins-8.0.28-1.el7.x86_64
mysql-community-client-8.0.28-1.el7.x86_64
mysql-community-libs-compat-8.0.28-1.el7.x86_64
mysql-community-common-8.0.28-1.el7.x86_64
mysql-community-libs-8.0.28-1.el7.x86_64
mysql-community-icu-data-files-8.0.28-1.el7.x86_64
mysql-community-server-8.0.28-1.el7.x86_64