CentOS 7 上安装 MySQL 8.0 的完整教程|gwozai

CentOS 7 上安装 MySQL 8.0 的完整教程

以下是基于 CentOS 7（或 RHEL 7）系统安装 MySQL 8.0 的完整步骤指南。假设你是 root 用户操作，系统是干净的（无旧 MySQL/MariaDB）。如果有问题，提供命令输出排查。参考官方文档：dev.mysql.com。

1. 检查和清理旧残留（避免冲突）

检查已安装包：

rpm -qa | grep -i mysql
rpm -qa | grep -i mariadb

移除残留（如 mariadb-libs）：
```
yum remove mariadb-libs mysql* -y
```

检查服务和目录：

systemctl status mysqld || systemctl status mysql
ps aux | grep mysql
ls -la /var/lib/mysql /etc/my.cnf /var/log/mysqld.log

如果有残留，停止服务并删除（备份数据）：

systemctl stop mysqld
rm -rf /var/lib/mysql
rm -f /etc/my.cnf /var/log/mysqld.log

2. 添加 MySQL YUM 仓库

安装最新仓库 RPM（如果已安装旧版，先移除）：

yum remove mysql80-community-release* -y
yum install https://repo.mysql.com/mysql80-community-release-el7-11.noarch.rpm -y

验证仓库：
```
yum repolist | grep mysql
```
清理缓存：
```
yum clean all
yum makecache
```

3. 安装 MySQL Server

更新系统（可选）：
```
yum update -y
```
安装：
```
yum install mysql-community-server -y
```

如果 YUM 失败，手动下载 RPM（最新版如 8.0.44）：

wget https://repo.mysql.com/yum/mysql-8.0-community/el/7/x86_64/mysql-community-common-8.0.44-1.el7.x86_64.rpm
wget https://repo.mysql.com/yum/mysql-8.0-community/el/7/x86_64/mysql-community-libs-8.0.44-1.el7.x86_64.rpm
wget https://repo.mysql.com/yum/mysql-8.0-community/el/7/x86_64/mysql-community-client-8.0.44-1.el7.x86_64.rpm
wget https://repo.mysql.com/yum/mysql-8.0-community/el/7/x86_64/mysql-community-client-plugins-8.0.44-1.el7.x86_64.rpm
wget https://repo.mysql.com/yum/mysql-8.0-community/el/7/x86_64/mysql-community-icu-data-files-8.0.44-1.el7.x86_64.rpm
wget https://repo.mysql.com/yum/mysql-8.0-community/el/7/x86_64/mysql-community-server-8.0.44-1.el7.x86_64.rpm

安装（顺序重要）：

rpm -ivh mysql-community-common-*.rpm mysql-community-libs-*.rpm mysql-community-client-plugins-*.rpm mysql-community-icu-data-files-*.rpm mysql-community-client-*.rpm mysql-community-server-*.rpm

导入 GPG 密钥（如果提示）：

rpm --import https://repo.mysql.com/RPM-GPG-KEY-mysql-2023

4. 启动和配置服务

启动服务：

systemctl start mysqld
systemctl enable mysqld
systemctl status mysqld

获取临时密码：

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

5. 修改密码和安全配置

用临时密码登录（替换 <temp_password>）：
```
mysql -u root -p<temp_password>
```

在 mysql> 提示符下，降低密码策略（如果用弱密码如 ‘123456’）：

SET GLOBAL validate_password.policy = LOW;
SET GLOBAL validate_password.length = 4;
ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
FLUSH PRIVILEGES;
exit;

非交互方式（shell 命令）：

mysql -u root -p$(grep 'temporary password' /var/log/mysqld.log | awk '{print $NF}') -e "SET GLOBAL validate_password.policy = LOW; SET GLOBAL validate_password.length = 4;"
mysql -u root -p$(grep 'temporary password' /var/log/mysqld.log | awk '{print $NF}') -e "ALTER USER 'root'@'localhost' IDENTIFIED BY '123456'; FLUSH PRIVILEGES;"

6. 配置远程访问（外网访问）

编辑配置文件（用 sed 创建/修改）：

echo '' | sed 'i\[mysqld]\nbind-address=0.0.0.0\nvalidate_password.policy=LOW\nvalidate_password.length=4' > /etc/my.cnf

重启服务：
```
systemctl restart mysqld
```

授予远程权限：

mysql -u root -p123456 -e "CREATE USER IF NOT EXISTS 'root'@'%' IDENTIFIED BY '123456'; GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' WITH GRANT OPTION; FLUSH PRIVILEGES;"

7. 配置防火墙

启用防火墙（如果未启）：

systemctl start firewalld
systemctl enable firewalld

放行 3306 端口：

firewall-cmd --permanent --add-port=3306/tcp
firewall-cmd --reload

8. 安全加固（等效 mysql_secure_installation，非交互）

mysql -u root -p123456 -e "DELETE FROM mysql.user WHERE User=''; DROP DATABASE IF EXISTS test; DELETE FROM mysql.db WHERE Db='test' OR Db='test\\_%'; FLUSH PRIVILEGES;"