Linux在线yum方式安装mysql5.7（适用于mysql8.0）

Linux下软件常见部署方式有三种：yum安装、rpm安装以及编译安装。由于离线、编译需要先下载多个文件再安装，步骤较多，所以整理了一下在线安装mysql的方法，文中系统为CentOS7.9版本。

1.配置好yum源，包括epel源

wget -qO /etc/yum.repos.d/epel.repo http://mirrors.myhuaweicloud.com/repo/epel-7.repo
yum makecache
yum install epel-release -y >/dev/null 2>&1

yum repolist all | grep mysql
#如果输入后没有反应，则表示本地还没有mysql的源，需要去官网下载了。

使用官方yum仓库，官方下载链接

wget https://dev.mysql.com/get/mysql80-community-release-el7-7.noarch.rpm

yum install mysql80-community-release-el7-7.noarch.rpm

2. 生成yum源缓存并查看mysql版本

[root@localhost ~]# yum makecache
[root@localhost ~]# yum repolist all | grep mysql
mysql-cluster-7.5-community/x86_64           MySQL Cluster 7.5 C disabled
mysql-cluster-7.5-community-source           MySQL Cluster 7.5 C disabled
mysql-cluster-7.6-community/x86_64           MySQL Cluster 7.6 C disabled
mysql-cluster-7.6-community-source           MySQL Cluster 7.6 C disabled
mysql-cluster-8.0-community/x86_64           MySQL Cluster 8.0 C disabled
mysql-cluster-8.0-community-debuginfo/x86_64 MySQL Cluster 8.0 C disabled
mysql-cluster-8.0-community-source           MySQL Cluster 8.0 C disabled
mysql-connectors-community/x86_64            MySQL Connectors Co enabled:    206
mysql-connectors-community-debuginfo/x86_64  MySQL Connectors Co disabled
mysql-connectors-community-source            MySQL Connectors Co disabled
mysql-tools-community/x86_64                 MySQL Tools Communi enabled:     94
mysql-tools-community-debuginfo/x86_64       MySQL Tools Communi disabled
mysql-tools-community-source                 MySQL Tools Communi disabled
mysql-tools-preview/x86_64                   MySQL Tools Preview disabled
mysql-tools-preview-source                   MySQL Tools Preview disabled
mysql57-community/x86_64                     MySQL 5.7 Community disabled
mysql57-community-source                     MySQL 5.7 Community disabled
mysql80-community/x86_64                     MySQL 8.0 Community enabled:    367
mysql80-community-debuginfo/x86_64           MySQL 8.0 Community disabled
mysql80-community-source                     MySQL 8.0 Community disabled

从enable状态来看，默认启用的是最新8.0版本，如果想要使用5.7版本，需要使用到YUM 管理工具包，此包提供了 yum-config-manager 命令工具：

[root@localhost ~]# yum -y install yum-utils
[root@localhost ~]# yum-config-manager --disable mysql80-community
[root@localhost ~]# yum-config-manager --enable mysql57-community

此时查看mysql5.7版本已经被启用了

[root@localhost ~]# yum repolist enabled |grep mysql
mysql-connectors-community/x86_64       MySQL Connectors Community           206
mysql-tools-community/x86_64            MySQL Tools Community                 94
mysql57-community/x86_64                MySQL 5.7 Community Server           624

3.安装MySql并启用

安装Mysql

yum install -y  mysql-community-server    #视网络情况而定，需要等待

查看版本

设置开机自启并启动

systemctl start mysqld
systemctl enable mysqld

4. 初始化mysql

在 MySQL 服务器初始启动时，如果服务器的数据目录为空，则会发生以下情况：
- MySQL 服务器已初始化
- 在数据目录中生成SSL证书和密钥文件
- 安装并启用该 validate_password 插件
- 将创建一个超级用户帐户’root’@‘localhost’。并会设置超级用户的密码，将其存储在错误日志文件/var/log/mysqld.log中

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

我们可以用上述临时密码登陆mysql，但是自从mysql5.7版本之后自带了安全配置向导命令mysql_secure_installation，下面我们将以此方式来进行。

运行mysql_secure_installation会执行几个设置：
- 为root用户设置密码
- 删除匿名账号
- 取消root用户远程登录
- 删除test库和对test库的访问权限
- 刷新授权表使修改生效

[root@localhost ~]# mysql_secure_installation

Securing the MySQL server deployment.

Enter password for user root:                #设置root密码，需要大小写英文+数字+特殊符号
The 'validate_password' plugin is installed on the server.
The subsequent steps will run with the existing configuration
of the plugin.
Using existing password for root.

Estimated strength of the password: 100
Change the password for root ? ((Press y|Y for Yes, any other key for No) : y

New password:

Re-enter new password:

Estimated strength of the password: 100
Do you wish to continue with the password provided?(Press y|Y for Yes, any other key for No) : y                                         #默认选择是
By default, a MySQL installation has an anonymous user,
allowing anyone to log into MySQL without having to have
a user account created for them. This is intended only for
testing, and to make the installation go a bit smoother.
You should remove them before moving into a production
environment.

Remove anonymous users? (Press y|Y for Yes, any other key for No) : y
Success.                                        #移除匿名用户


Normally, root should only be allowed to connect from
'localhost'. This ensures that someone cannot guess at
the root password from the network.

Disallow root login remotely? (Press y|Y for Yes, any other key for No) : y
Success.                                        #关闭root远程登陆

By default, MySQL comes with a database named 'test' that
anyone can access. This is also intended only for testing,
and should be removed before moving into a production
environment.


Remove test database and access to it? (Press y|Y for Yes, any other key for No) : y
                                                #移除test数据库
 - Dropping test database...
Success.

 - Removing privileges on test database...
Success.

Reloading the privilege tables will ensure that all changes
made so far will take effect immediately.

Reload privilege tables now? (Press y|Y for Yes, any other key for No) : y
Success.                                        #重新加载用户权限表

All done!

5.远程访问mysql数据库

创建新的MySQL用户账户，用于远程访问MySQL。

MySQL默认占用的端口号为3306。使用过程中需要防火墙放行3306端口。
创建并配置远程访问MySQL的账号。
- 依次运行以下命令，并允许远程主机使用该账号访问MySQL。
- 账号为cnaaa、密码为PASSword123!
  - mysql> create user ‘cnaaa’@’%’ identified by ‘PASSword123!’;
  - mysql> grant all privileges on . to ‘cnaaa’@’%’with grant option;
  - mysql> flush privileges;
使用cnaaa账号远程登录MySQL。