Centos7 yum安装mysql5.7

1、配置yum源

• 在MySQL官网中下载YUM源rpm安装包：

下载mysql源安装包

[root@jumpserver ~]# sudo wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm

安装mysql源

[root@jumpserver ~]# sudo yum localinstall mysql57-community-release-el7-8.noarch.rpm
已加载插件：fastestmirror
正在检查 mysql57-community-release-el7-8.noarch.rpm: mysql57-community-release-el7-8.noarch
mysql57-community-release-el7-8.noarch.rpm 将被安装
正在解决依赖关系
--> 正在检查事务
---> 软件包 mysql57-community-release.noarch.0.el7-8 将被 安装
--> 解决依赖关系完成

依赖关系解决

==============================================================================================================================================================================================================================================================================

 Package                                                                 架构                                                 版本                                                源                                                                                     大小
==============================================================================================================================================================================================================================================================================

正在安装:
 mysql57-community-release                                               noarch                                               el7-8                                               /mysql57-community-release-el7-8.noarch                                               8.2 k

事务概要
==============================================================================================================================================================================================================================================================================

安装  1 软件包

总计：8.2 k
安装大小：8.2 k
Is this ok [y/d/N]: y
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  正在安装    : mysql57-community-release-el7-8.noarch                                                                                                                                                                                                                    1/1 
  验证中      : mysql57-community-release-el7-8.noarch                                                                                                                                                                                                                    1/1 

已安装:
  mysql57-community-release.noarch 0:el7-8                                                                                                                                                                                                                                    

完毕！

• 检查MySQL源是否安装成功

[root@jumpserver ~]# sudo yum repolist enabled | grep "mysql.*-community.*"
mysql-connectors-community/x86_64       MySQL Connectors Community           203
mysql-tools-community/x86_64            MySQL Tools Community                129
mysql57-community/x86_64                MySQL 5.7 Community Server           504
[root@jumpserver ~]# 

出现图上红色字体部分表示安装成功

2、安装mysql5.7

[root@jumpserver ~]# sudo yum install mysql-community-server

3、启动MySQL服务

[root@jumpserver ~]# sudo systemctl start mysqld   #######启动mysql
[root@jumpserver ~]# systemctl status mysqld        #######查看mysql启动状态
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: active (running) since 三 2021-05-26 11:03:04 CST; 11s ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 4496 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
  Process: 4142 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 4499 (mysqld)
   Memory: 290.6M
   CGroup: /system.slice/mysqld.service
           └─4499 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid

5月 26 11:02:59 jumpserver systemd[1]: Starting MySQL Server...
5月 26 11:03:04 jumpserver systemd[1]: Started MySQL Server.
[root@jumpserver ~]# 
[root@jumpserver ~]# sudo systemctl enable mysqld        #######加入开机启动
[root@jumpserver ~]# sudo systemctl daemon-reload		 #######重新加载

4、查看mysql的root登陆密码

• mysql安装完成之后，在/var/log/mysqld.log文件中给root生成了一个默认密码。通过以下命令找到密码：

[root@jumpserver ~]# sudo grep 'temporary password' /var/log/mysqld.log
2021-05-26T03:03:01.391524Z 1 [Note] A temporary password is generated for root@localhost: VMnXXXXXXdB
[root@jumpserver ~]# 

5、登录MySQL，使用刚才找到的密码，修改初始密码

[root@jumpserver ~]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.34

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> 
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass4!';   ####密码修改方法一
Query OK, 0 rows affected (0.00 sec)
mysql> set password for 'root'@'localhost'=password('sdfkji@sal1');  ###注意密码复杂度
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> 
mysql> set password for 'root'@'localhost'=password('aPalss4!');    ###密码修改方法二
Query OK, 0 rows affected, 1 warning (0.00 sec)

注意：mysql5.7默认安装了密码安全检查插件（validate_password），默认密码检查策略要求密码必须包含：大小写字母、数字和特殊符号，并且长度不能少于8位。否则会提示ERROR 1819 (HY000): Your password does not satisfy the current policy requirements错误，如下图所示：

• 通过msyql环境变量可以查看密码策略的相关信息

mysql>show variables like '%password%';

--下面参数是默认策略MEDIUM的密码检查规则：
validate_password_policy：            --密码策略，默认为MEDIUM策略
validate_password_dictionary_file：   --密码策略文件，策略为STRONG才需要
validate_password_length：            --密码最少长度
validate_password_mixed_case_count：  --大小写字符长度，至少1个
validate_password_number_count ：     --数字至少1个
validate_password_special_char_count：--特殊字符至少1个