xip dns 服務在我們的實際開發中，還是挺有用的，我們可以基於dns模式方便的進行軟件開發，同時
結合nginx 的虛擬主機，可以實現靈活的軟件部署，以下是基於coredns 的template plugin 實現一個
簡單，但是高效的xip 服務
xip 格式說明
- 參考格式
10.0.0.1.xip.name resolves to 10.0.0.1
www.10.0.0.2.xip.name resolves to 10.0.0.2
foo.10.0.0.3.xip.name resolves to 10.0.0.3
bar.baz.10.0.0.4.xip.name resolves to 10.0.0.4
- 說明
我們主要實現以下格式的
foo.10.0.0.3.xip.name resolves to 10.0.0.3
環境准備
- docker-compose 文件
version: "3"
services:
lb:
image: openresty/openresty:alpine
networks:
service1_net:
ipv4_address: 192.168.1.2
volumes:
- "./nginx-lb.conf:/usr/local/openresty/nginx/conf/nginx.conf"
- "./dns.log:/var/log/nginx/dns.log"
ports:
- "53:53/udp"
- "80:80"
- "53:53/tcp"
coredns:
image: coredns/coredns:1.7.0
networks:
service1_net:
ipv4_address: 192.168.1.4
volumes:
- "./Corefile:/opt/Corefile"
command: -conf /opt/Corefile
networks:
service1_net:
ipam:
driver: default
config:
- subnet: 192.168.1.0/16
- 說明
基於nginx做dns 的proxy，基於coredns提供xip服務 - nginx 配置
worker_processes 1;
user root;
events {
worker_connections 1024;
}
stream {
upstream dns_servers {
server 192.168.1.4:53;
}
server {
listen 53 udp;
listen 53; #tcp
proxy_pass dns_servers;
error_log /var/log/nginx/dns.log info;
}
}
http {
include mime.types;
default_type text/html;
gzip on;
resolver 127.0.0.1 ipv6=off valid=30s;
real_ip_header X-Forwarded-For;
real_ip_recursive on;
server {
listen 80;
charset utf-8;
default_type text/html;
location / {
index index.html;
default_type text/html;
set $kuaidi100 "www.kuaidi100.com";
proxy_pass https://$kuaidi100;
proxy_redirect off;
proxy_set_header Bloom-Request-Shard 1;
proxy_read_timeout 10000;
proxy_send_timeout 10000;
proxy_buffer_size 1M;
proxy_buffers 8 1M;
proxy_busy_buffers_size 1M;
proxy_temp_file_write_size 1M;
proxy_set_header Host $kuaidi100;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Host $server_name;
proxy_set_header X-Forwarded-Proto $scheme;
}
}
}
- coredns 配置
Corefile 文件
我們基於正則以及template plugin生成xip服務，實際上很簡單，我們利用了coredns 提供的變量
以及正則分組別名，快速的實現了一個xip服務
dalongrong.com:53 {
log
template IN A dalongrong.com {
match ^(?P<a>\w+)\.(?P<b>\d+\.\d+\.\d+\.\d+)\.dalongrong\.com\.$
answer "{{ .Name }} 60 IN A {{ .Group.b }}"
authority "dalongrong.com. 60 IN NS ns0.dalongrong.com."
authority "dalongrong.com. 60 IN NS ns1.dalongrong.com."
additional "ns0.dalongrong.com. 60 IN A 203.0.113.8"
additional "ns1.dalongrong.com. 60 IN A 198.51.100.8"
fallthrough
}
}
.:53 {
log
health
cache 30
loadbalance round_robin
forward . 8.8.8.8 8.8.4.4 114.114.114.114
}
- 啟動
docker-compose up -d
測試
- dig 命令
我們希望..dalongrong.com 解析的dns為 就可以實現此功能了
命令
dig @127.0.0.1 openresty.192.168.0.190.dalongrong.com
效果 
說明
以上支持實現了部分xip服務，但是已經夠我們實際使用了，具體其他模式的主要是正則的編寫，有空了可以寫下
參考支持xip 的一個coredns 配置
dalongrong.com:53 {
log
template IN A dalongrong.com {
match (\D*?)\.?(?P<b>\d+\.\d+\.\d+\.\d+)\.dalongrong\.com\.$
answer "{{ .Name }} 60 IN A {{ .Group.b }}"
authority "dalongrong.com. 60 IN NS ns0.dalongrong.com."
authority "dalongrong.com. 60 IN NS ns1.dalongrong.com."
additional "ns0.dalongrong.com. 60 IN A 203.0.113.8"
additional "ns1.dalongrong.com. 60 IN A 198.51.100.8"
fallthrough
}
}
.:53 {
log
health
cache 30
loadbalance round_robin
forward . 8.8.8.8 8.8.4.4 114.114.114.114
}
參考資料
https://coredns.io/plugins/template/
https://github.com/rongfengliang/nginx-coredns-consul-learning/tree/xip