Alibaba Cloud Linux 2(Centos7)安装mysql8.0.md

本文首次发布于博客园：https://www.cnblogs.com/lxm-cnblog/articles/17202074.html 现在转移到 github pages 上。

1. 检查是否安装历史版本，如果有则删除相关文件

查找并删除历史版本mysql

rpm -qa|grep mysql
# 如果存在则删除
rpm -ev [组件名称]
# 查找残留文件
find / -name mysql

删除配置以及数据

# 删除配置
rm -rf /etc/my.cnf
# 删除数据目录
cd /var/lib/mysql
rm -rf *

查找并删除已有mysql依赖

# 查找依赖
rpm -qa | grep mysql
# 如果有则删除
rpm -e [mysql_libs]
# 若删除失败则强力删除
rpm -e --nodeps [mysql_libs]

查看并删除mariadb

rpm -qa | grep mariadb
rpm -e --nodeps [mariadb]

2. 下载mysql8.0

  wget http://mirrors.tuna.tsinghua.edu.cn/mysql/yum/mysql80-community-el7/mysql80-community-release-el7-1.noarch.rpm

如果以下出现404错误

failure: repodata/repomd.xml from xxx: [Errno 256] No more mirrors to try.
  https://download.xxx.com/linux/centos/2.1903/x86_64/stable/repodata/repomd.xml: [Errno 14] HTTPS Error 404 - Not Found

这有可能是Alibaba Cloud Linux 2 的Centos版本的问题，可以有以下两种解决方法:
1. 下载Centos7 yum源
```
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
yum clean all 
yum list 
yum makecache
```
2. 找到/etc/yum.repos.d下的repo文件, 将其中的所有$releasever替换成7

3. 安装mysql

  # 安装mysql依赖包
  yum install -y libaio
  # 安装mysql
  rpm -ivh mysql80-community-release-el7-1.noarch.rpm
  yum install mysql-server

若出现Public key for mysql-community-server-5.7.37-1.el7.x86_64.rpm is not installed则需要更新mysql的GPA
```
rpm --import https://repo.mysql.com/RPM-GPG-KEY-mysql-2022
# 然后再安装
yum install mysql-server
```

4. 配置并启动mysql

设为开机启动

  # 检查是否开机启动
  systemctl list-unit-files|grep mysqld
  # 若没有则设为开机启动
  systemctl enable mysqld.service

初始化mysql

  mysqld --initialize
  # 查看初始化密码
  grep 'temporary password' /var/log/mysqld.log
  # 登录mysql
  mysql -uroot -p

可能会出现的报错:

如果出现Can't connect to local MySQL server through socket '/var/lib /mysql/mysql.sock' (111)

 # 进入报错路径并删除mysql.sock，再重启服务
 cd /var/lib/mysql/ 
 rm -rf mysql.sock 
 systemctl stop mysqld 
 systemctl start mysqld 
 // 然后登入mysql查看是否正常 
 mysql -u root -p 

如果启动报错

 service mysqld start
 Redirecting to /bin/systemctl start mysqld.service
 Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.

执行以下指令
```
   chown mysql:mysql -R /var/lib/mysql
```

如果出现Failed to start mysqld.service: Unit not found

   yum -y install mariadb  mariadb-devel  mariadb-server

修改密码

  alter user 'root'@'localhost' identified by '12345678';

如果提示ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
```
set global validate_password.policy=0;
```

远程授权

  grant all privileges on *.* to 'root'@'%' identified by '12345678' with grant option;

如果出现check the manual that corresponds to your MySQL server version for the right syntax to

原因是我采用的mysql版本是8.0.13，给新用户授权时有所变化

 -- 创建账户
 create user 'root'@'xxx.xxx.xxx.xxx' identified by 'password'
 -- 授权，with grant option指该用户可以将自己拥有的权限授权给别人
 grant all privileges on *.* to 'root'@'xxx.xxx.xxx.xxx' with grant option

刷新权限
```
flush privileges;
```

目录导航

1. 检查是否安装历史版本，如果有则删除相关文件

2. 下载mysql8.0

3. 安装mysql

4. 配置并启动mysql