linux笔记13

主从DNS同步

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当单一DNS无法满足客户需求是开启一个同步的次级DNS，他们dns的内容一致。

主机：

vim /etc/named.rfc1912.zones

zone "asd.com" IN {

type master;

file "asd.com.zone";

allow-update { none; };

allow-transfer { 172.25.254.225; }; 从机地址

};

systemctl restart named

从机：

yum install bind -y 安装服务

vim /etc/named.conf 修改配置文件

options {

listen-on port 53 { any; };

listen-on-v6 port 53 { ::1; };

directory "/var/named";

dump-file "/var/named/data/cache_dump.db";

statistics-file "/var/named/data/named_stats.txt";

memstatistics-file "/var/named/data/named_mem_stats.txt";

allow-query { any; };

dnssec-validation no; 同主机一致

vim /etc/named.rfc1912.zones

zone "asd.com" IN {

type slave; 设置为从机

masters { 172.25.254.125; }; 主机地址

file "slaves/asd.com.zone";

allow-update { none; };

};

systemctl restart named 重启服务

（检测结果）

[root@localhost ~]# dig www.asd.com

; <<>> DiG 9.9.4-RedHat-9.9.4-14.el7 <<>> www.asd.com

;; global options: +cmd

;; Got answer:

;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 63544

;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 2

;; OPT PSEUDOSECTION:

; EDNS: version: 0, flags:; udp: 4096

;; QUESTION SECTION:

;www.asd.com.INA

;; ANSWER SECTION:

www.asd.com.86400INA172.25.254.126

DNS修改同步

从机：

systemctl stop firewalld 关闭火墙，允许通知通过

主机：

vim /etc/named.rfc1912.zones

zone "asd.com" IN {

type master;

file "asd.com.zone";

allow-update { none; };

allow-transfer { 172.25.254.225; };

also-notify { 172.25.254.225; }; 通知从机同步更新

};

vim /var/named/asd.com.zone

$TTL 1D

@ IN SOA dns.asd.com. root.asd.com. (

01 ; serial 修改serial，提示有更新（最多10位）文件在更新是查看的比较值

1D ; refresh

1H ; retry

1W ; expire

3H ) ; minimum

NS dns.asd.com.

dns A 172.25.254.125

www A 172.25.254.128 DNS更新

systemctl restart named 重启服务并通知从机更新dns

『测试结果』

主从机DNS保持一致，主机更新，从机同步更新

DNS远程更新

主机（服务端）

setenforce 0 更改selinux

chmod 770 /var/named 更改目录权限

vim /etc/named.rfc1912.zones 修改文件

zone "asd.com" IN {

type master;

file "asd.com.zone";

allow-update { 172.25.254.225; }; 发送新的dns的地址

};

发送端：

nsupdate

> server 172.25.254.125 更改的dns ip

> update delete www.asd.com 删除

> send发送

> server 172.25.254.125

> update add www.asd.com 86400 A 172.25.254.120 添加新的dns （86400 缓存一天）

> send

> quit 退出

注：当完成> server 172.25.254.125

> update delete www.asd.com

> send

后主机端的/var/named/会出一个asd.com.zone.jnl

当systemctl retsart named 后该文件会覆盖原本的asd.com.zone，所以建议提前备份

『测试结果』

远程可以更改主机的dns服务（可以进行删除和添加）

DNS远程更新（加密）

主机：

dnssec-keygen -a HMAC-MD5 -b 100 -n HOST gou （-a 加密类型 -b加密字节 -n 加密用途）

获得公钥和私钥

cp -p /etc/rndc.key /etc/gou.key 复制模版

vim /etc/gou.key 编写内容

key "gou" { 加密名称

algorithm hmac-md5; 格式

secret "/pLHdCuATXkKuZNjGQ=="; 密码

};

vim /etc/named.conf

43 include "/etc/gou.key";

vim /etc/named.rfc1912.zones 修改配置文件

zone "asd.com" IN {

type master;

file "asd.com.zone";

allow-update { key gou; }; 只接受有key的人的修改

};

scp Kgou.+157+64442.* root@172.25.254.225:/mnt 远程发送密码给用户以更新dnsderen

systemctl restart named 重启服务

发送端：

[root@localhost mnt]# nsupdate -k Kgou.+157+64442.private（-k 用密匙的方式）

> server 172.25.254.125

> update delete www.asd.com 删除

> send

> quit退出

『测试结果』

root@localhost named]# ls

asd.com.zone data named.ca named.localhost slaves

asd.com.zone.jnl dynamic named.empty named.loopback

root@localhost named]# dig www.asd.com

; <<>> DiG 9.9.4-RedHat-9.9.4-14.el7 <<>> www.asd.com

;; global options: +cmd

;; Got answer:

;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 55177

;; flags: qr aa rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:

; EDNS: version: 0, flags:; udp: 4096

;; QUESTION SECTION:

;www.asd.com.INA

;; AUTHORITY SECTION:

asd.com.10800INSOAdns.asd.com. root.asd.com. 3 86400 3600 604800 10800

DDNS(花生壳)动态DNS获取

yum install dhcp -y 安装dhcp

cp /usr/share/doc/dhcp-4.2.5/dhcpd.conf.example /etc/dhcp/dhcpd.conf 复制模版

vim /etc/dhcp/dhcpd.conf 配置文件

6 # option definitions common to all supported networks...

7 option domain-name "asd.com"; 域名

8 option domain-name-servers 172.25.254.125;dns ip

13 # Use this to enble / disable dynamic dns updates globally.

14 ddns-update-style interim; 开启dhcp时通知dns

30 subnet 172.25.254.0 netmask 255.255.255.0 { 子网掩码

31 range 172.25.254.247 172.25.254.249; ip获取段

32 option routers 172.25.254.125;

33 }

34 key gou { key名称

35 algorithm hmac-md5; 加密方式

36 secret /pLHdCuATXkKuZNjGQ==;

37 };

38 zone asd.com. {

39 primary 127.0.0.1; 自循环

40 key gou;

41 }

vim /var/named/asd.com.zone 复原该文件

systemctl restart named

systemctl restart dhcpd 重启服务

客户端：

更改ip获取方式为dhcp

hostnamectl set-hostname bbq.asd.com 更改主机名（必须属于asd域）

systemctl restart network 重启服务

『测试结果』

dig bbq.asd.com

结果与客户端ip一致

数据库

yum install mariadb-server.x86_64 -y 数据库服务的安装

vim /etc/my.cnf 修改配置文件

# Settings user and group are ignored when systemd is used.

# If you need to run MySQLd under a different user or group,

# customize your systemd unit file for mariadb according to the

# instructions in http://fedoraproject.org/wiki/Systemd

skip-networking=1 关闭网卡上的数据库端口

systemctl restart mariadb 重启服务

[root@localhost named]# mysql_secure_installation 开启安全机制

/usr/bin/mysql_secure_installation: line 379: find_mysql_client: command not found

NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MariaDB

SERVERS IN PRODUCTION USE! PLEASE READ EACH STEP CAREFULLY!

In order to log into MariaDB to secure it, we'll need the current

password for the root user. If you've just installed MariaDB, and

you haven't set the root password yet, the password will be blank,

so you should just press enter here.

Enter current password for root (enter for none): 输入密码（无）

OK, successfully used password, moving on...

Setting the root password ensures that nobody can log into the MariaDB

root user without the proper authorisation.

Set root password? [Y/n] y 设置密码

New password:

Re-enter new password:

Password updated successfully!

Reloading privilege tables..

... Success!

By default, a MariaDB installation has an anonymous user, allowing anyone

to log into MariaDB 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? [Y/n] y 关闭匿名访问

... Success!

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? [Y/n] y 不允许root远程访问

... Success!

By default, MariaDB 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? [Y/n] y 不允许临时数据库

- 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? [Y/n] y 刷新

... Success!

Cleaning up...

All done! If you've completed all of the above steps, your MariaDB

installation should now be secure.

Thanks for using MariaDB!

mysql -u root -p westos 登陆

数据库的查询(;表示命令输入完成)

MariaDB [(none)]> SHOW DATABASES; 显示数据库

+--------------------+

| Database |

+--------------------+

| information_schema |

| mysql |

| performance_schema |

+--------------------+

3 rows in set (0.00 sec)

MariaDB [(none)]> USE mysql; 进入数据库

Reading table information for completion of table and column names

You can turn off this feature to get a quicker startup with -A

Database changed

MariaDB [mysql]> SHOW TABLES; 显示数据库中的表

+---------------------------+

| Tables_in_mysql |

+---------------------------+

| columns_priv |

| db |

| event |

| func |

| general_log |

| help_category |

| help_keyword |

| help_relation |

| help_topic |

| host |

| ndb_binlog_index |

| plugin |

| proc |

| procs_priv |

| proxies_priv |

| servers |

| slow_log |

| tables_priv |

| time_zone |

| time_zone_leap_second |

| time_zone_name |

| time_zone_transition |

| time_zone_transition_type |

| user |

+---------------------------+

24 rows in set (0.00 sec)

MariaDB [mysql]> SELECT User,Host,Password FROM user; 查看user表中的host，user，password字段

+------+-----------+-------------------------------------------+

| User | Host | Password |

+------+-----------+-------------------------------------------+

| root | localhost | *28C1E2BE21B45562A34B6CC34A19CFAFC2F88F96 |

| root | 127.0.0.1 | *28C1E2BE21B45562A34B6CC34A19CFAFC2F88F96 |

| root | ::1 | *28C1E2BE21B45562A34B6CC34A19CFAFC2F88F96 |

+------+-----------+-------------------------------------------+

3 rows in set (0.00 sec)

MariaDB [mysql]> CREATE DATABASE asd ; 创建一个数据库

MariaDB [mysql]> USE asd; 进入数据库

MariaDB [asd]> CREATE TABLE UTAB ( uer varchar(10) not null, password varchar(8) not null, age varchar(3) ); 创建一张表（用户名【10】不能没有，密码【8】不能没有，年龄【3】可以不添）

MariaDB [asd]> SHOW TABLES; 显示数据库

+---------------+

| Tables_in_asd |

+---------------+

| UTAB |

+---------------+

MariaDB [asd]> DESC UTAB ; 显示表的属性

+----------+-------------+------+-----+---------+-------+

+----------+-------------+------+-----+---------+-------+

| uer | varchar(10) | NO | | NULL | |

| age | varchar(3) | YES | | NULL | |

+----------+-------------+------+-----+---------+-------+

MariaDB [asd]> INSERT INTO UTAB VALUES ('asd','qwe','24'); 添加内容进表

Query OK, 1 row affected (0.00 sec)

MariaDB [asd]> SELECT * FROM UTAB ; 显示表

+-----+----------+------+

| uer | password | age |

+-----+----------+------+

| asd | qwe | 24 |

+-----+----------+------+

MariaDB [asd]> ALTER TABLE UTAB ADD class varchar(8) AFTER password ; 添加一个字段在password后

Query OK, 1 row affected (0.03 sec)

Records: 1 Duplicates: 0 Warnings: 0

MariaDB [asd]> UPDATE UTAB SET ; class附值

Query OK, 1 row affected (0.00 sec)

Rows matched: 1 Changed: 1 Warnings: 0

MariaDB [asd]> SELECT * FROM UTAB;

+-----+----------+-------+------+

| uer | password | class | age |

+-----+----------+-------+------+

| asd | qwe | 1 | 24 |

+-----+----------+-------+------+

MariaDB [asd]> UPDATE UTAB SET WHERE uer='asd'; class值的修改

Query OK, 1 row affected (0.01 sec)

Rows matched: 1 Changed: 1 Warnings: 0

MariaDB [asd]> SELECT * FROM UTAB;

+-----+----------+-------+------+

| uer | password | class | age |

+-----+----------+-------+------+

| asd | qwe | 3 | 24 |

+-----+----------+-------+------+

MariaDB [asd]> INSERT INTO UTAB VALUES ('asd','qwe','24');

ERROR 1136 (21S01): Column count doesn't match value count at row 1

MariaDB [asd]> INSERT INTO UTAB VALUES ('gou','qwe','','24');

Query OK, 1 row affected (0.01 sec)

MariaDB [asd]> SELECT * FROM UTAB;

+-----+----------+-------+------+

| uer | password | class | age |

+-----+----------+-------+------+

| asd | qwe | 3 | 24 |

| gou | qwe | | 24 |

+-----+----------+-------+------+

MariaDB [asd]> DELETE FROM UTAB uer='gou'; 删除某一列

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'uer='gou'' at line 1

MariaDB [asd]> DELETE FROM UTAB WHERE uer='gou';

Query OK, 1 row affected (0.01 sec)

MariaDB [asd]> SELECT * FROM UTAB;

+-----+----------+-------+------+

| uer | password | class | age |

+-----+----------+-------+------+

| asd | qwe | 3 | 24 |

+-----+----------+-------+------+

MariaDB [asd]> DROP TABLE UTAB 删除表

-> ;

Query OK, 0 rows affected (0.00 sec)

MariaDB [asd]> SELECT * FROM UTAB;

ERROR 1146 (42S02): Table 'asd.UTAB' doesn't exist

MariaDB [asd]> DROP DATABASE asd; 删除库

Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> SELECT * FROM UTAB;

ERROR 1046 (3D000): No database selected

MariaDB [(none)]> SHOW DATABASES

-> ;

+--------------------+

| Database |

+--------------------+

| information_schema |

| mysql |

| performance_schema |

+--------------------+

3 rows in set (0.00 sec)

数据库用户的权限和访问

MariaDB [(none)]> CREATE USER we@localhost identified by 'westos';

Query OK, 0 rows affected (0.00 sec) 创建用户we，密码为westos，仅可本地登陆（we@'%'可远程登陆）

MariaDB [(none)]> GRANT CREATE ON *.* TO we@localhost ;

Query OK, 0 rows affected (0.00 sec) 授权可以在任意库的任意表中创建

MariaDB [(none)]> SHOW GRANTS FOR we@localhost ; 权限显示

+------------------------------------------------------------------------------------------------------------+

| Grants for we@localhost |

+------------------------------------------------------------------------------------------------------------+

| GRANT CREATE ON *.* TO 'we'@'localhost' IDENTIFIED BY PASSWORD '*28C1E2BE21B45562A34B6CC34A19CFAFC2F88F96' |

+------------------------------------------------------------------------------------------------------------+

1 row in set (0.00 sec)

MariaDB [(none)]> GRANT INSERT ON *.* to we@localhost ;

Query OK, 0 rows affected (0.00 sec) 可以在任意库的任意表中插入

MariaDB [(none)]> SHOW GRANTS FOR we@localhost ; 权限查看

+--------------------------------------------------------------------------------------------------------------------+

| Grants for we@localhost |

+--------------------------------------------------------------------------------------------------------------------+

| GRANT INSERT, CREATE ON *.* TO 'we'@'localhost' IDENTIFIED BY PASSWORD '*28C1E2BE21B45562A34B6CC34A19CFAFC2F88F96' |

+--------------------------------------------------------------------------------------------------------------------+

1 row in set (0.00 sec)

FLUSH PRIVILEGES ；重载授权表

MariaDB [(none)]> REVOKE CREATE on *.* from we@localhost ;

Query OK, 0 rows affected (0.00 sec) 撤销用户创建权限

MariaDB [(none)]> DROP USER we@localhost ; 删除用户

Query OK, 0 rows affected (0.00 sec)

数据库密码

当忘记密码：

systemctl stop mariadb.service 停止服务

mysqld_safe --skip-grant-tables & 开启安全模式

[root@localhost ~]# fg

mysqld_safe --skip-grant-tables

[1]+ Stopped mysqld_safe --skip-grant-tables

mysql -u root 进入数据库

MariaDB [(none)]> UPDATE mysql.user set Password='redhat' WHERE User='root' ; 更新密码（明文）

Query OK, 3 rows affected (0.00 sec)

Rows matched: 3 Changed: 3 Warnings: 0

| localhost | root | redhat | Y | Y | Y | Y

MariaDB [(none)]> UPDATE mysql.user set Password=password('redhat') WHERE User='root' ; 更新密码（加密）

Query OK, 3 rows affected (0.00 sec)

Rows matched: 3 Changed: 3 Warnings: 0

[root@localhost ~]# fg 查看后台

mysqld_safe --skip-grant-tables

[1]+ Stopped mysqld_safe --skip-grant-tables

[root@localhost ~]# killall -9 mysqld_safe 关闭后台进程

[1]+ Killed mysqld_safe --skip-grant-tables

[root@localhost ~]# ps aux | grep mysql 查看进程

mysql 3196 0.0 4.8 859060 91736 pts/0 Sl 20:52 0:00 /usr/libexec/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql --skip-grant-tables --log-error=/var/log/mariadb/mariadb.log --pid-file=/var/run/mariadb/mariadb.pid --socket=/var/lib/mysql/mysql.sock

root 3416 0.0 0.0 112640 940 pts/0 R+ 20:58 0:00 grep --color=auto mysql

[root@localhost ~]# kill -9 3196 关闭

systemctl start mariadb 开启服务（可以正常登陆）

修改密码：

mysqladmin -uroot -predhat password westos

数据库的备份和恢复

MariaDB [(none)]> CREATE DATABASE westos ;

MariaDB [westos]> CREATE TABLE UTAB (user varchar(10)not null, password varchar(10)not null, class varchar(5) );

MariaDB [westos]> INSERT INTO UTAB VALUES ('asd','123','4');

Query OK, 1 row affected (0.01 sec)

MariaDB [westos]> INSERT INTO UTAB VALUES ('lee','123','');

Query OK, 1 row affected (0.01 sec)

MariaDB [westos]> SELECT * FROM UTAB;

+------+----------+-------+

| user | password | class |

+------+----------+-------+

| asd | 123 | 4 |

| lee | 123 | |

+------+----------+-------+

（创建一个实验用的数据库）

[root@localhost ~]# mysqldump -uroot -pwestos westos > /mnt/westos.sql 备份数据库

-- MySQL dump 10.14 Distrib 5.5.35-MariaDB, for Linux (x86_64)

-- Host: localhost Database: westos

-- ------------------------------------------------------

-- Server version5.5.35-MariaDB

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;

/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;

/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;

/*!40101 SET NAMES utf8 */;

/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;

/*!40103 SET TIME_ZONE='+00:00' */;

/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;

/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;

/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;

/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;

-- Table structure for table `UTAB`

DROP TABLE IF EXISTS `UTAB`;

/*!40101 SET @saved_cs_client = @@character_set_client */;

/*!40101 SET character_set_client = utf8 */;

CREATE TABLE `UTAB` (

`user` varchar(10) NOT NULL,

`password` varchar(10) NOT NULL,

`class` varchar(5) DEFAULT NULL

) ENGINE=InnoDB DEFAULT CHARSET=latin1;

/*!40101 SET character_set_client = @saved_cs_client */;

-- Dumping data for table `UTAB`

LOCK TABLES `UTAB` WRITE;

/*!40000 ALTER TABLE `UTAB` DISABLE KEYS */;

INSERT INTO `UTAB` VALUES ('asd','123','4'),('lee','123','');

/*!40000 ALTER TABLE `UTAB` ENABLE KEYS */;

UNLOCK TABLES;

/*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;

/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;

/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;

/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;

/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;

/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;

/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;

/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;

-- Dump completed on 2016-11-26 21:26:37

mysqldump -uroot -pwestos westos --no-data 只备份表格不备份其中数据

mysqldump -uroot -pwestos westos --all-database 备份全部

mysql -uroot -pwestos -e "SHOW DATABASES;"

mysql -uroot -pwestos -e "DROP westos;" 删除原有库（非交互）

mysql -uroot -pwestos -e "DROP DATABASE westos;"

mysql -uroot -pwestos -e "SHOW DATABASES;"

mysql -uroot -pwestos -e "CREATE DATABASE westos;"

mysql -uroot -pwestos westos < /mnt/westos.sql 恢复数据库

[root@localhost ~]# mysql -uroot -pwestos -e "SELECT * FROM westos.UTAB;"

+------+----------+-------+

| user | password | class |

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