内网主从智能DNS从此不再烦恼

大家好，我是小姜。

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，新手可能看懵逼，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

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，分别解析http://www.ayunw.cn、http://web.iyunw.cn以及http://allen.allenjol.cn，都是能正常解析的。

$ 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 172.16.0.55ns2.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，那么你换一台不在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。

或者如果你用172.16.10.1去解析http://web.iyunw.cn或者是http://allen.allenjol.cn，那么就无法正常解析了。这就是acl+view实现的智能DNS的效果。

最后，求关注。如果你还想看更多优质原创文章，欢迎关注我们的公众号「运维开发故事」。

如果我的文章对你有所帮助，还请帮忙点赞、在看、转发一下，你的支持会激励我输出更高质量的文章，非常感谢！

你还可以把我的公众号设为「星标」，这样当公众号文章更新时，你会在第一时间收到推送消息，避免错过我的文章更新。

posted @ 2023-04-18 20:04 GaoYanbing 阅读(45) 评论(0) 编辑收藏举报

会员力量，点亮园子希望

刷新页面返回顶部

Balance

内网主从智能DNS从此不再烦恼

写在前面

环境说明

bind9 master节点部署

编辑主named.conf文件

使用acl+view

生成区域文件

生成区域解析库文件

启动服务并设置开机自启

bind9 slave节点部署

编辑从named.conf文件

生成区域文件

启动服务并设置开机自启

测试解析

公告