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BIND9主从智能DNS部署

 ·   ·  ☕ 6 分钟  ·  ✍ ayunw

写在前面

随着云原生时代的快速发展,各行各业纷纷进军k8s,短短两三年,招聘上面就要求“至少有一年k8s实战经验”。以至于好多传统的、行业初期用的人非常多的一些技术被飞快的甩在后头。亦或者说技术更新迭代层出不穷,老技术会被很快代替,新技术会备受宠爱。而在域名解析领域,大家最熟悉的常用的云解析DNSPod、Godaddy、CloudFlare、阿里云的域名解析等,当然还有dnsmasq、powerdns以及在k8s中用的coreDNS。但是今天我这里就聊聊bind9。

可能目前的中小型公司都不会使用bind9,而且网上你去搜索,大多都是直接使用named服务,不会使用named-chroot。而且更少的是使用acl+view的。要么排版不够好,新手可能看蒙蔽,配置错误。要么就是没有说的很详细的。当然也有,可能我没有好好花时间搜索或者搜索能力有限。这里我就记录一下bind9使用chroot以及使用acl+view试图实现智能DNS过程。

环境说明

CentOS Linux release 8.4.2105

BIND Version:9.11.26

总网段:172.16.128.0/17

bind9主从所在网段:172.16.0.0/24

Host IP Role
named-srv1 172.16.0.55 named master
named-srv2 172.16.0.56 named slave

bind9 master节点部署

/bin/chattr -i /etc/fstab /etc/passwd /etc/group /etc/shadow /etc/sudoers /etc/services

dnf -y install bind-chroot bind-utils


# 我要启用chroot,并且需要更改named的目录到/data/named/chroot
# 因此需要拷贝文件
mkdir -p /data/named
cp -ar /var/named/* /data/named/


# 创建存放日志的目录
mkdir -p /data/named/chroot/data/log/named/

### 在bind chroot 的目录中创建相关文件
touch /data/named/chroot/var/named/data/cache_dump.db
touch /data/named/chroot/var/named/data/named_stats.txt
touch /data/named/chroot/var/named/data/named_mem_stats.txt
touch /data/named/chroot/var/named/data/named.run
mkdir /data/named/chroot/var/named/dynamic
touch /data/named/chroot/var/named/dynamic/managed-keys.bind

# 到linux系统的/data/目录下,更改named目录的属主和数组为named
cd /data/
chown named.named -R named

编辑主named.conf文件

$ cat /data/named/chroot/etc/named.conf

acl telecom {
  172.17.10.0/24;
};

acl unicom {
  172.17.20.0/24;
};

acl mobile {
  172.17.30.0/24;
};

options {
	listen-on port 53 { 127.0.0.1; 172.16.0.55;};
	directory 	"/var/named";
	dump-file 	"/data/named/data/cache_dump.db";
	statistics-file "/data/named/data/named_stats.txt";
	memstatistics-file "/data/named/data/named_mem_stats.txt";
    // 允许查询的主机;白名单 
	allow-query     { any; };
    allow-query-cache  { any; };
    // 我这里买的是阿里云的ECS服务器,因此这里使用阿里的DNS
    forwarders { 223.5.5.5; 223.6.6.6; };
    recursive-clients  200000;
    check-names master warn;
    max-cache-ttl	     60;
    max-ncache-ttl	   0;

	//recursion yes;
	//dnssec-enable yes;
	//dnssec-validation yes;
	//managed-keys-directory "/var/named/dynamic";
	pid-file "/run/named/named.pid";
	//session-keyfile "/run/named/session.key";

};

logging {
       channel query_log {
               file "/data/log/named/query.log" versions 10 size 300m;
               severity info;
               print-category yes;
               print-time yes;
               print-severity yes;
               };
       channel client_log {
               file "/data/log/named/client.log" versions 3 size 200m;
               severity info;
               print-category yes;
               print-time yes;
               print-severity yes;
               };
       channel config {
               file "/data/log/named/config.log" versions 3 size 100m;
               severity info;
               print-category yes;
               print-time yes;
               print-severity yes;
               };
       channel default_log {
               file "/data/log/named/default.log" versions 3 size 100m;
               severity debug;
               print-category yes;
               print-time yes;
               print-severity yes;
               };
       channel general_log {
               file "/data/log/named/general.log" versions 3 size 200m;
               severity debug;
               print-category yes;
               print-time yes;
               print-severity yes;
               };
       category queries {
               query_log;
               };
       category client {
               client_log;
               };
       category general {
               general_log;
               };
       category config {
               config;
               };
       category default {
               default_log;
               };
};

view telcom_view {
  match-clients { telcom; };
  match-destinations { any };
  recursion yes;
  include "/etc/named-telcome.zones";
};

view unicom_view {
  match-clients { unicom; };
  match-destinations { any; };
  recursion yes;
  include "/etc/named-unicome.zones";
};

view  mobile_view {
  match-clients      { any; };
  match-destinations { any; };
  recursion yes;
  include "/etc/named-mobile.zones";
};

注意:需要提醒大家的是,第一,启用了named-chroot服务以后,就必须关闭named服务,两者取其一。第二,如果启用了named-chroot,那么目录就都是相对目录,都是相对于/var/named/chroot而言的。

使用acl+view

上面已经定义好了三个acl和三个view。一般来说我们的acl都会放在最开头,也就是options的前面,也建议这样放。

接下来就需要生成三个view下面的include包含进来的区域文件了。这里只演示正向解析区域,一般内网bind9很少需要反向解析。

生成区域文件

$ vi /var/named/chroot/etc/named-telcome.zones
zone "ayunw.cn" IN {
        type master;
        file "ayunw.cn.zone";
        allow-update { none; };
        masterfile-format text;
        allow-transfer { 172.16.0.56; };
};

$ vi /var/named/chroot/etc/named-unicom.zones
zone "iyunw.cn" IN {
        type master;
        file "iyunw.cn.zone";
        allow-update { none; };
        masterfile-format text;
        allow-transfer { 172.16.0.56; };
};

$ vi /var/named/chroot/etc/named-mobile.zones
zone "allenjol.cn" IN {
        type master;
        file "allenjol.cn.zone";
        allow-update { none; };
        masterfile-format text;
        allow-transfer { 172.16.0.56; };
};

生成区域解析库文件

$ cd /var/named/chroot/var

$ vi ayunw.cn.zone
$TTL    86400
@       IN      SOA     ayunw.cn.       root.iyunw.cn.  (
                                        202111011       ; serial (d. adams)
                                        1H              ; refresh
                                        15M             ; retry
                                        1W              ; expiry
                                        1D )            ; minimum

                IN      NS              ns1.ayunw.cn.
                IN      NS              ns2.ayunw.cn.

ns1             IN      A	172.16.0.55
ns2             IN      A	172.16.0.56
www             IN      A 172.16.0.58



$ vi iyunw.cn.zone
$TTL    86400
@       IN      SOA     iyunw.cn.       root.iyunw.cn.  (
                                        202111011       ; serial (d. adams)
                                        1H              ; refresh
                                        15M             ; retry
                                        1W              ; expiry
                                        1D )            ; minimum

                IN      NS              ns1.iyunw.cn.
                IN      NS              ns2.iyunw.cn.

ns1             IN      A	172.16.0.55
ns2             IN      A	172.16.0.56
web             IN      A   172.16.0.59

$ vi allenjol.cn.zone
$TTL    86400
@       IN      SOA     allenjol.cn.       root.allenjol.cn.  (
                                        202111011       ; serial (d. adams)
                                        1H              ; refresh
                                        15M             ; retry
                                        1W              ; expiry
                                        1D )            ; minimum

                IN      NS              ns1.allenjol.cn.
                IN      NS              ns2.allenjol.cn.

ns1             IN      A	172.16.0.55
ns2             IN      A	172.16.0.56
allen           IN      A   172.16.0.60

启动服务并设置开机自启

/usr/libexec/setup-named-chroot.sh /var/named/chroot on
systemctl stop named
systemctl disable named
systemctl start named-chroot
systemctl enable named-chroot

bind9 slave节点部署

/bin/chattr -i /etc/fstab /etc/passwd /etc/group /etc/shadow /etc/sudoers /etc/services

dnf -y install bind-chroot bind-utils

# 我要启用chroot,并且需要更改named的目录到/data/named/chroot
# 因此需要拷贝文件
mkdir -p /data/named
cp -ar /var/named/* /data/named/


# 创建存放日志的目录
mkdir -p /data/named/chroot/data/log/named/

### 在bind chroot 的目录中创建相关文件
touch /data/named/chroot/var/named/data/cache_dump.db
touch /data/named/chroot/var/named/data/named_stats.txt
touch /data/named/chroot/var/named/data/named_mem_stats.txt
touch /data/named/chroot/var/named/data/named.run
mkdir /data/named/chroot/var/named/dynamic
touch /data/named/chroot/var/named/dynamic/managed-keys.bind

# 到linux系统的/data/目录下,更改named目录的属主和数组为named
cd /data/
chown named.named -R named

编辑从named.conf文件

$ cat /data/named/chroot/etc/named.conf
$ cat /data/named/chroot/etc/named.conf

acl telecom {
  172.17.10.0/24;
};

acl unicom {
  172.17.20.0/24;
};

acl mobile {
  172.17.30.0/24;
};

options {
	listen-on port 53 { 127.0.0.1; 172.16.0.55;};
	directory 	"/var/named";
	dump-file 	"/data/named/data/cache_dump.db";
	statistics-file "/data/named/data/named_stats.txt";
	memstatistics-file "/data/named/data/named_mem_stats.txt";
    // 允许查询的主机;白名单 
	allow-query     { any; };
    allow-query-cache  { any; };
    // 我这里买的是阿里云的ECS服务器,因此这里使用阿里的DNS
    forwarders { 223.5.5.5; 223.6.6.6; };
    recursive-clients  200000;
    check-names master warn;
    max-cache-ttl	     60;
    max-ncache-ttl	   0;

	//recursion yes;
	//dnssec-enable yes;
	//dnssec-validation yes;
	//managed-keys-directory "/var/named/dynamic";
	pid-file "/run/named/named.pid";
	//session-keyfile "/run/named/session.key";

};

logging {
       channel query_log {
               file "/data/log/named/query.log" versions 10 size 300m;
               severity info;
               print-category yes;
               print-time yes;
               print-severity yes;
               };
       channel client_log {
               file "/data/log/named/client.log" versions 3 size 200m;
               severity info;
               print-category yes;
               print-time yes;
               print-severity yes;
               };
       channel config {
               file "/data/log/named/config.log" versions 3 size 100m;
               severity info;
               print-category yes;
               print-time yes;
               print-severity yes;
               };
       channel default_log {
               file "/data/log/named/default.log" versions 3 size 100m;
               severity debug;
               print-category yes;
               print-time yes;
               print-severity yes;
               };
       channel general_log {
               file "/data/log/named/general.log" versions 3 size 200m;
               severity debug;
               print-category yes;
               print-time yes;
               print-severity yes;
               };
       category queries {
               query_log;
               };
       category client {
               client_log;
               };
       category general {
               general_log;
               };
       category config {
               config;
               };
       category default {
               default_log;
               };
};

view telcom_view {
  match-clients { telcom; };
  match-destinations { any };
  recursion yes;
  include "/etc/named-telcome.zones";
};

view unicom_view {
  match-clients { unicom; };
  match-destinations { any; };
  recursion yes;
  include "/etc/named-unicome.zones";
};

view  mobile_view {
  match-clients      { any; };
  match-destinations { any; };
  recursion yes;
  include "/etc/named-mobile.zones";
};

生成区域文件

$ vi /var/named/chroot/etc/named-telcome.zones
zone "ayunw.cn" IN {
        type master;
        file "ayunw.cn.zone";
        allow-update { none; };
        masterfile-format text;
        allow-transfer { 172.16.0.56; };
};

$ vi /var/named/chroot/etc/named-unicom.zones
zone "iyunw.cn" IN {
        type master;
        file "iyunw.cn.zone";
        allow-update { none; };
        masterfile-format text;
        allow-transfer { 172.16.0.56; };
};

$ vi /var/named/chroot/etc/named-mobile.zones
zone "allenjol.cn" IN {
        type master;
        file "allenjol.cn.zone";
        allow-update { none; };
        masterfile-format text;
        allow-transfer { 172.16.0.56; };
};


### 启动服务并设置开机自启

/usr/libexec/setup-named-chroot.sh /var/named/chroot on
systemctl stop named
systemctl disable named
systemctl start named-chroot
systemctl enable named-chroot


注意:从节点无需创建区域解析库文件,当主节点重启named-chroot服务的时候会自动同步解析库文件到从节点




### 测试解析
找了三台机器,内网ip分别为:172.16.10.1、172.16.20.1、172.16.30.1进行解析

$ dig -t A www.ayunw.cn

; «» DiG 9.11.26-RedHat-9.11.26-4.el8_4 «» -t A allen.ptcloud.t.home
;; global options: +cmd
;; Got answer:
;; -»HEADER«- opcode: QUERY, status: NOERROR, id: 40756
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 3

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; COOKIE: e48c8996a6469b8d51d96afb61775ef045fa019e7ef2c4d6 (good)
;; QUESTION SECTION:
;www.ayunw.cn. IN A

;; ANSWER SECTION:
www.ayunw.cn. 86400 IN A 172.16.0.58

;; AUTHORITY SECTION:
ayunw.cn. 86400 IN NS ns2.ayunw.cn.
ayunw.cn. 86400 IN NS ns1.ayunw.cn.

;; ADDITIONAL SECTION:
ns1.ayunw.cn. 86400 IN A 172.16.0.55
ns2.ayunw.cn. 86400 IN A 172.16.0.56

;; Query time: 0 msec
;; SERVER: 172.16.0.55#53(172.16.0.55)
;; WHEN: Tue Oct 26 09:50:40 CST 2021
;; MSG SIZE rcvd: 161

$ dig -t A web.iyunw.cn

; «» DiG 9.11.26-RedHat-9.11.26-4.el8_4 «» -t A allen.ptcloud.t.home
;; global options: +cmd
;; Got answer:
;; -»HEADER«- opcode: QUERY, status: NOERROR, id: 40756
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 3

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; COOKIE: e48c8996a6469b8d51d96afb61775ef045fa019e7ef2c4d6 (good)
;; QUESTION SECTION:
;web.iyunw.cn. IN A

;; ANSWER SECTION:
web.iyunw.cn. 86400 IN A 172.16.0.59

;; AUTHORITY SECTION:
iyunw.cn. 86400 IN NS ns2.iyunw.cn.
iyunw.cn. 86400 IN NS ns1.iyunw.cn.

;; ADDITIONAL SECTION:
ns1.iyunw.cn. 86400 IN A 172.16.0.55
ns2.iyunw.cn. 86400 IN A 172.16.0.56

;; Query time: 0 msec
;; SERVER: 172.16.0.55#53(172.16.0.55)
;; WHEN: Tue Oct 26 09:50:40 CST 2021
;; MSG SIZE rcvd: 161

$ dig -t A allen.allenjol.cn

; «» DiG 9.11.26-RedHat-9.11.26-4.el8_4 «» -t A allen.ptcloud.t.home
;; global options: +cmd
;; Got answer:
;; -»HEADER«- opcode: QUERY, status: NOERROR, id: 40756
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 3

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; COOKIE: e48c8996a6469b8d51d96afb61775ef045fa019e7ef2c4d6 (good)
;; QUESTION SECTION:
;allen.allenjol.cn. IN A

;; ANSWER SECTION:
allen.allenjol.cn. 86400 IN A 172.16.0.60

;; AUTHORITY SECTION:
allenjol.cn. 86400 IN NS ns2.allenjol.cn.
allenjol.cn. 86400 IN NS ns1.allenjol.cn.

;; ADDITIONAL SECTION:
ns1.allenjol.cn. 86400 IN A 172.16.0.55
ns2.allenjol.cn. 86400 IN A 172.16.0.56

;; Query time: 0 msec
;; SERVER: 172.16.0.55#53(172.16.0.55)
;; WHEN: Tue Oct 26 09:50:40 CST 2021
;; MSG SIZE rcvd: 161


如果你有足够的机器,那么你换一太不在172.16.10.0/24、172.16.20.0/24、172.16.30.0、24这三个网段的机器,然后去任意解析
这三个zone文件中的域名,你会发现最终都是没有正常的A记录返回的


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ayunw
尼古丁的绑架没有救赎,我们皆是上瘾的囚徒


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