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NSD DBA1 DAY04

  1. MySQL管理工具
  2. 密码恢复及设置
  3. 用户授权及撤销

1 MySQL管理工具

1.1 问题

1.2 方案

1. 安装httpd、mysql、php-mysql及相关包

2. 启动httpd服务程序

3. 解压phpMyAdmin包,部署到网站目录

4. 配置config.inc.php,指定MySQL主机地址

5. 创建授权用户

6. 浏览器访问、登录使用

今天课程需要使用1台RHEL7虚拟机,其中一台作为数据服务器(192.168.4.6)、另外一台作为测试用的Linux客户机(192.168.4.254),如图-1所示。

图-1

1.3 步骤

实现此案例需要按照如下步骤进行。

步骤一:准备软件的运行环境 lamp

[root@mysql6~]# rpm -q httpd  php  php-mysql    //检测是否安装软件包
未安装软件包 httpd 
未安装软件包 php 
未安装软件包 php-mysql
[root@mysql6~]# yum  -y   install   httpd     php    php-mysql  //装包
[root@mysql6~]# systemctl  start  httpd       //启动服务
[root@mysql6~]# systemctl  enable httpd      //设置开机自启
Created symlink from /etc/systemd/system/multi-user.target.wants/httpd.service to /usr/lib/systemd/system/httpd.service.

步骤二:测试运行环境

[root@mysql6~]# vim  /var/www/html/test.php     //编辑页面测试文件
[root@mysql6~]# cat /var/www/html/test.php      //查看页面测试文件
<?php
$x=mysql_connect("localhost","root","123456");
if($x){   echo "ok";    }else{    echo "no";    };
?>
[root@mysql6~]# yum  -y   install  elinks     //安装测试网页工具
[root@mysql6~]#  elinks   --dump   http://localhost/test.php
   Ok                                                //验证测试页面成功

步骤三:安装软件包

1)物理机传输解压包给虚拟机192.168.4.6

[root@room9pc桌面]# scp phpMyAdmin-2.11.11-all-languages.tar.gz 192.168.4.6:/root/
root@192.168.4.6's password: 
phpMyAdmin-2.11.11-a 100% 4218KB 122.5MB/s   00:00

2)虚拟机192.168.4.6解压phpMyAdmin-2.11.11-all-languages.tar.gz压缩包

[root@mysql6~]# tar -zxf phpMyAdmin-2.11.11-all-languages.tar.gz -C /var/www/html/   //-C 表示改变至目录
[root@mysql6~]# cd /var/www/html/
[root@mysql6~]# mv phpMyAdmin-2.11.11-all-languages  phpmyadmin //改变目录名
[root@mysql6~]#  chown  -R  apache:apache  phpmyadmin/ //改变phpmyadmin目录权限

步骤四:修改软件的配置文件定义管理的数据库服务器

切换到部署后的phpmyadmin程序目录,拷贝配置文件,并修改配置以正确指定MySQL服务器的地址

[root@mysql6html]# cd  phpmyadmin
[root@mysql6 phpmyadmin]# cp   config.sample.inc.php   config.inc.php  
//备份主配置文件
[root@mysql6 phpmyadmin]# vim   config.inc.php  //编辑主配置文件
17 $cfg['blowfish_secret'] = 'plj123';     //给cookie做认证的值,可以随便填写
31 $cfg['Servers'][$i]['host'] = 'localhost';  //指定主机名,定义连接哪台服务器
:wq                   

步骤五:在客户端访问软件 管理数据库服务器

1)在客户端访问软件,打开浏览器输入http://192.168.4.6/phpmyadmin(数据库服务器地址) 访问软件,如图-2所示,用户名是root,密码是123456

图-2

2)登入成功后,如图-3示,即可在授权范围内对MySQL数据库进行管理。

/

图-3

2 密码恢复及设置

2.1 问题

本案例要求密码恢复及设置,完成以下任务操作:

2.2 步骤

实现此案例需要按照如下步骤进行。

步骤一:重置MySQL管理密码

1)首先停止已运行的MySQL服务程序

[root@dbsvr1 ~]# systemctl  stop mysqld.service   		//停止服务
[root@dbsvr1 ~]# systemctl  status mysqld.service  	    //确认状态
mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled)
   Active: inactive (dead) since 五 2017-04-07 23:01:38 CST; 21s ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 20260 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
  Process: 20238 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 20262 (code=exited, status=0/SUCCESS)

2)然后跳过授权表启动MySQL服务程序

这一步主要利用mysqld的 --skip-grant-tables选项

修改my.cnf配置,添加 skip_grant_tables=1启动设置:

[root@dbsvr1 ~]# vim /etc/my.cnf
[mysqld]
skip_grant_tables=1
.. ..
[root@dbsvr1 ~]# systemctl  restart mysqld.service
[root@dbsvr1 ~]# service mysql status
mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled)
   Active: active (running) since 五 2017-04-07 23:40:20 CST; 40s ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 11698 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
  Process: 11676 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 11701 (mysqld)
   CGroup: /system.slice/mysqld.service
           └─11701 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.p...

3)使用mysql命令连接到MySQL服务,重设root的密码

由于前一步启动的MySQL服务跳过了授权表,所以可以root从本机直接登录

[root@dbsvr1 ~]# mysql -u root
Enter password:                                 //直接回车即可
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.17 MySQL Community Server (GPL)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

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> 

进入 mysql> 环境后,通过修改mysql库中user表的相关记录,重设root用户从本机登录的密码:

mysql> UPDATE mysql.user SET authentication_string=PASSWORD('1234567')
    -> WHERE user='root' AND host='localhost';  			//重设root的密码
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 1
mysql> FLUSH PRIVILEGES;  								//刷新授权表
Query OK, 0 rows affected (0.01 sec)
mysql> exit  											//退出mysql> 环境
Bye

通过执行“FLUSH PRIVILEGES;”可使授权表立即生效,对于正常运行的MySQL服务,也可以用上述方法来修改密码,不用重启服务。本例中因为是恢复密码,最好重启MySQL服务程序,所以上述“FLUSH PRIVILEGES;”操作可跳过。

4)重新以正常方式启动MySQL服务程序,验证新密码

如果前面是修改/etc/my.cnf配置的方法来跳过授权表,则重置root密码后,应去除相应的设置以恢复正常:

[root@dbsvr1 ~]# vim /etc/my.cnf
[mysqld]
#skip_grant_tables=1  							//注释掉或删除此行
.. ..

按正常方式,通过mysql脚本重启服务即可:

[root@dbsvr1 ~]# systemctl  restart mysqld.service

验证无密码登录时,将会被拒绝:

[root@dbsvr1 ~]# mysql -u root
Enter password:                            //没有跳过授权表回车会报错
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

只有提供重置后的新密码,才能成功登入:

[root@dbsvr1 ~]# mysql -u root –p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.17 MySQL Community Server (GPL)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

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> 

步骤二:正常设置MySQL管理密码

正常的前提是:已知当前MySQL管理用户(root)的密码。

1)方法1,在Shell命令行下设置

使用mysqladmin管理工具,需要验证旧的密码。比如,以下操作将会把root的密码设置为 1234567:

[root@dbsvr1 ~]# mysqladmin -u root -p password '1234567'					
Enter password:                                   //验证原来的密码
mysqladmin: [Warning] Using a password on the command line interface can be insecure.
Warning: Since password will be sent to server in plain text, use ssl connection to ensure password safety.                              //提示明文修改不安全,并不是报错

2)方法2,以root登入mysql> 后,使用SET PASSWORD指令设置

这个与新安装MySQL-server后首次修改密码时要求的方式相同,平时也可以用:

mysql> SET PASSWORD FOR root@localhost=PASSWORD('1234567');
Query OK, 0 rows affected, 1 warning (0.00 sec)

3)方法3,以root登入mysql> 后,使用GRANT授权工具设置

这个是最常见的用户授权方式(下一节会做更多授权的练习):

mysql> GRANT all ON *.* TO root@localhost IDENTIFIED BY '1234567';
Query OK, 0 rows affected, 1 warning (0.00 sec)

4)方法4,以root登入mysql> 后,使用UPDATE更新相应的表记录

这种方法与恢复密码时的操作相同:

mysql> UPDATE mysql.user SET authentication_string=PASSWORD('1234567')
    -> WHERE user='root' AND host='localhost';  		//重设root的密码
Query OK, 0 rows affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 0  Warnings: 1
mysql> FLUSH PRIVILEGES;  								//刷新授权表
Query OK, 0 rows affected (0.00 sec)

在上述方法中,需要特别注意:当MySQL服务程序以 skip-grant-tables 选项启动时,如果未执行“FLUSH PRIVILEGES;”操作,是无法通过SET PASSWORD或者GRANT方式来设置密码的。比如,验证这两种方式时,都会看到ERROR 1290的出错提示:

mysql> SET PASSWORD FOR root@localhost=PASSWORD('1234567');
ERROR 1290 (HY000): The MySQL server is running with the --skip-grant-tables option so it cannot execute this statement

mysql> GRANT all ON *.* TO root@localhost IDENTIFIED BY '1234567';
ERROR 1290 (HY000): The MySQL server is running with the --skip-grant-tables option so it cannot execute this statement

3 用户授权及撤销

3.1 问题

3.2 方案

使用2台RHEL 7虚拟机,如图-1所示。其中192.168.4.10是MySQL服务器,授权及撤销操作均在此服务器上执行;而192.168.4.120作为测试客户机,需要安装好MySQL-client软件包,以便提供mysql命令。

图-1

同时,MySQL服务器本身(192.168.4.10)也可以作为测试客户机。

3.3 步骤

实现此案例需要按照如下步骤进行。

步骤一:用户授权及撤销

1)允许root从192.168.4.0/24访问,对所有库表有完全权限,密码为tarena。

授权之前,从192.168.4.0/24网段的客户机访问时,将会被拒绝:

[root@host120 ~]# mysql -u root -p -h 192.168.4.10
Enter password:  								//输入正确的密码
ERROR 2003 (HY000): Host '192.168.4.120' is not allowed to connect to this MySQL server

授权操作,此处可设置与从localhost访问时不同的密码:

mysql> GRANT all ON *.* TO root@'192.168.4.%' IDENTIFIED BY 'tarena';
Query OK, 0 rows affected (0.00 sec)

再次从192.168.4.0/24网段的客户机访问时,输入正确的密码后可登入:

[root@host120 ~]# mysql -u root -p -h 192.168.4.10
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 20
Server version: 5.7.17 MySQL Community Server (GPL)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

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>

从网络登入后,测试新建一个库、查看所有库:

mysql> CREATE DATABASE rootdb;  				//创建新库rootdb
Query OK, 1 row affected (0.06 sec)

mysql> SHOW DATABASES;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| home               |
| mysql              |
| performance_schema |
| rootdb             |                         //新建的rootdb库
| sys                |
| userdb             |
+--------------------+
7 rows in set (0.01 sec)

2)在Mysql服务器上建立一个管理账号dba007,对所有库完全控制,并赋予其授权的权限

新建账号并授权:

mysql> GRANT all ON *.* TO dba007@localhost
    -> IDENTIFIED BY '1234567'
    -> WITH GRANT OPTION;
Query OK, 0 rows affected (0.00 sec)

查看dba007的权限:

mysql> SHOW GRANTS FOR dba007@localhost;
+-----------------------------------------------------------------------+
| Grants for dba007@localhost                                           |
+-----------------------------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO 'dba007'@'localhost' WITH GRANT OPTION |
+-----------------------------------------------------------------------+
1 row in set (0.00 sec)

3)撤销root从本机访问的权限,然后恢复

注意:如果没有事先建立其他管理账号,请不要轻易撤销root用户的本地访问权限,否则恢复起来会比较困难,甚至不得不重装数据库。

撤销root对数据库的操作权限:

mysql> REVOKE all ON *.* FROM root@localhost;
Query OK, 0 rows affected (0.00 sec)
mysql> SHOW GRANTS FOR root@localhost;
+--------------------------------------------------------------+
| Grants for root@localhost                                    |
+--------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'root'@'localhost' WITH GRANT OPTION   |
| GRANT PROXY ON ''@'' TO 'root'@'localhost' WITH GRANT OPTION |
+--------------------------------------------------------------+
2 rows in set (0.00 sec)

验证撤销后的权限效果:

mysql> exit  									//退出当前MySQL连接
Bye
[root@dbsvr1 ~]# mysql -u root -p  				//重新以root从本地登入
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.6.15 MySQL Community Server (GPL)

Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

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> CREATE DATABASE newdb2014;  				//尝试新建库失败
ERROR 1044 (42000): Access denied for user 'root'@'localhost' to database 'newdb2014'
mysql> DROP DATABASE rootdb;  						//尝试删除库失败
ERROR 1044 (42000): Access denied for user 'root'@'localhost' to database 'rootdb'

尝试以当前的root用户恢复权限,也会失败(无权更新授权表):

mysql> GRANT all ON *.* TO root@localhost IDENTIFIED BY '1234567';
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

怎么办呢?

退出当前MySQL连接,以上一步添加的管理账号dba007登入:

mysql> exit  										//退出当前MySQL连接
Bye
[root@dbsvr1 ~]# mysql -u dba007 -p   				//以另一个管理账号登入
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 24
Server version: 5.7.17 MySQL Community Server (GPL)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

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.

由管理账号dba007重新为root添加本地访问权限:

mysql> GRANT all ON *.* TO root@localhost IDENTIFIED BY '1234567';
Query OK, 0 rows affected (0.00 sec)
mysql> SHOW GRANTS FOR root@localhost;  			//查看恢复结果
+---------------------------------------------------------------------+
| Grants for root@localhost                                           |
+---------------------------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' WITH GRANT OPTION |
| GRANT PROXY ON ''@'' TO 'root'@'localhost' WITH GRANT OPTION        |
+---------------------------------------------------------------------+
2 rows in set (0.00 sec)

退出,再重新以root登入,测试一下看看,权限又恢复了吧:

mysql> exit  									//退出当前MySQL连接
Bye
[root@dbsvr1 ~]# mysql -u root -p 				//重新以root登入
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 25
Server version: 5.7.17 MySQL Community Server (GPL)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

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> CREATE DATABASE newdb2014;  				//成功创建新库
Query OK, 1 row affected (0.00 sec)

4)允许webuser从任意客户机登录,只对webdb库有完全权限,密码为 888888

添加授权:

mysql> GRANT all ON webdb.* TO webuser@'%' IDENTIFIED BY '888888';
Query OK, 0 rows affected (0.00 sec)

查看授权结果:

mysql> SHOW GRANTS FOR webuser@'%';
+----------------------------------------------------+
| Grants for webuser@%                               |
+----------------------------------------------------+
| GRANT USAGE ON *.* TO 'webuser'@'%'                |
| GRANT ALL PRIVILEGES ON `webdb`.* TO 'webuser'@'%' |
+----------------------------------------------------+
2 rows in set (0.00 sec)

5)撤销webuser的完全权限,改为查询权限

撤销所有权限:

mysql> REVOKE all ON webdb.* FROM webuser@'%';
Query OK, 0 rows affected (0.00 sec)

只赋予查询权限:

mysql> GRANT select ON webdb.* TO webuser@'%';
Query OK, 0 rows affected (0.00 sec)

确认授权更改结果:

mysql> SHOW GRANTS FOR webuser@'%';
+--------------------------------------------+
| Grants for webuser@%                       |
+--------------------------------------------+
| GRANT USAGE ON *.* TO 'webuser'@'%'        |
| GRANT SELECT ON `webdb`.* TO 'webuser'@'%' |
+--------------------------------------------+
2 rows in set (0.00 sec)