【MySQL】在centos7 純IPv6環境下，安裝mysql5.7

參考鏈接：https://mirrors6.tuna.tsinghua.edu.cn/help/mysql/

服務器環境：
Centos7
純IPv6環境（不能與IPv4互通）

1. 按照 https://mirrors6.tuna.tsinghua.edu.cn/help/mysql/ 步驟操作完成

2. 執行 yum install mysql-community-server 發現默認安裝 mysql 8.0，

   問題：提示找不到簽名，因爲https://repo.mysql.com/ 只有v4地址，估將https://repo.mysql.com/RPM-GPG-KEY-mysql 下載至 /root 目錄下，

3. 修改 /etc/yum.repos.d/mysql-community.repo

[mysql-connectors-community]
name=MySQL Connectors Community
baseurl=https://mirrors.tuna.tsinghua.edu.cn/mysql/yum/mysql-connectors-community-el7-$basearch/
enabled=1
gpgcheck=1
gpgkey=https://repo.mysql.com/RPM-GPG-KEY-mysql

[mysql-tools-community]
name=MySQL Tools Community
baseurl=https://mirrors.tuna.tsinghua.edu.cn/mysql/yum/mysql-tools-community-el7-$basearch/
enabled=1
gpgcheck=1
gpgkey=https://repo.mysql.com/RPM-GPG-KEY-mysql

[mysql-5.6-community]
name=MySQL 5.6 Community Server
baseurl=https://mirrors.tuna.tsinghua.edu.cn/mysql/yum/mysql-5.6-community-el7-$basearch/
enabled=0
gpgcheck=1
gpgkey=https://repo.mysql.com/RPM-GPG-KEY-mysql

[mysql-5.7-community]
name=MySQL 5.7 Community Server
baseurl=https://mirrors.tuna.tsinghua.edu.cn/mysql/yum/mysql-5.7-community-el7-$basearch/
enabled=1
gpgcheck=1
gpgkey=file:///root/RPM-GPG-KEY-mysql
#gpgkey=https://repo.mysql.com/RPM-GPG-KEY-mysql

# 註釋 8.0
#[mysql-8.0-community]
#name=MySQL 8.0 Community Server
#baseurl=https://mirrors.tuna.tsinghua.edu.cn/mysql/yum/mysql-8.0-community-el7-$basearch/
#enabled=1
#gpgcheck=1
#gpgkey=https://repo.mysql.com/RPM-GPG-KEY-mysql

4. 再次執行 yum install mysql-community-server 成功安裝

5. 啓動mysql服務 systemctl start mysqld

6. 進入 mysql mysql -u root -p ，回車

問題：需要密碼，從安裝到啓動服務，也沒有設置過密碼啊，故更改配置，免密登錄

7. 更改配置文件/etc/my.cnf

[mysqld]
skip-grant-tables

8. 啓動mysql服務 systemctl restart mysqld

9. 再次執行 mysql -u root -p ，回車成功進入，更改root 密碼

update mysql.user set authentication_string=PASSWORD('xxx') where user='root' and host='localhost';
flush privileges;

exit;

9. 關閉 免密登錄，即 註釋 skip-grant-tables （第7步），重啓mysql

10. 測試登錄 mysql -u root -p

11. 結束安裝