1 前言

MySQL相信不用笔者多做介绍，本章将要使用yum部署MySQL 8。

2 最佳实践

2.1 系统环境

OS = CentOS 7.3 x86_64
IP = any
Host Name = any.cmdschool.org

2.2 安装前准备

2.2.1 配置安装源

vim /etc/yum.repos.d/mysql-8.0-community-rhel7.repo

加入如下配置，

[mysql80-community]
name=MySQL 8.0 Community Server
baseurl=http://repo.mysql.com/yum/mysql-8.0-community/el/7/$basearch/
enabled=1
gpgcheck=1
gpgkey=http://repo.mysql.com/RPM-GPG-KEY-mysql

2.2.2 安装常用工具

yum install -y vim

2.3 部署软件包

yum install -y mysql-community-server mysql-community-client

2.4 配置MySQL服务

2.4.1 启动服务并设置自启动

systemctl start mysqld.service
systemctl enable mysqld.service

另外，我们建议使用如下命令确实服务已经启动，

systemctl status mysqld.service

2.4.2 关闭密码复杂度要求

cp /etc/my.cnf /etc/my.cnf.default
vim /etc/my.cnf

加入如下配置

[mysqld]
# Disable password complexity check
validate_password.policy=low
validate_password.length=4

设置完成后，你需要重启数据库服务使配置生效，

systemctl restart mysqld.service

2.4.3 查询初始密码

grep "temporary password" /var/log/mysqld.log

可见如下显示，

2020-06-10T08:28:45.672805Z 6 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: ouB!Cg4cmuFd

2.4.4 运行初始化向导

mysql_secure_installation

向导如下，

[...]
Enter password for user root:******
[...]
New password:******
Re-enter new password:******
[...]
Do you wish to continue with the password provided?(Press y|Y for Yes, any other key for No) : y
[...]
Remove anonymous users? (Press y|Y for Yes, any other key for No) : y
[...]
Disallow root login remotely? (Press y|Y for Yes, any other key for No) : n
[...]
Remove test database and access to it? (Press y|Y for Yes, any other key for No) : y
[...]
Reload privilege tables now? (Press y|Y for Yes, any other key for No) : y
[...]

2.4.5 登录测试

mysql -uroot -p

2.5 迁移数据目录

2.5.1 登录测试

systemctl stop mysqld.service

2.5.2 迁移数据到新的存储目录

mv /var/lib/mysql /data/

mkdir /var/lib/mysql

2.5.3 修改配置声明存储目录位置

vim /etc/my.cnf

修改如下配置，

[mysqld]
# datadir=/var/lib/mysql
datadir=/data/mysql
socket=/var/lib/mysql/mysql.sock
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
validate_password.policy=low
validate_password.length=4

根据配置重建“socket”参数所需的目录，

mkdir /var/lib/mysql
chown mysql:mysql /var/lib/mysql

2.5.4 关闭SELinux

sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
setenforce 0

2.5.5 尝试启动服务

systemctl start mysqld.service

2.5 授予应用程序访问前线

mysql -uroot -p
create user 'user1'@'localhost' identified with mysql_native_password by 'password';
grant all privileges on db1.* to 'user1'@'localhost';
flush privileges;

注：由于MySQL8已经将身份认证插件由“mysql_native_password”修改为“caching_sha2_password”，故而需要使用特别的函数生成密码。