基于coredns External Plugins redis插件修改

基于https://coredns.io/explugins/redis/ 进行修改，本次支持EDNS查询解析功能
支持按运营商，省份进行调度
基于https://github.com/lionsoul2014/ip2region/tree/master/binding/golang IP库进行查询解析
主要数据结构如下
使用方法下载coredns源码，修改plugin.cfg文件在最后一行增加smartdns:github.com/voilet/smartdns 修改后使用make编译即可
使用方法在corefile中增加smartdns插件即可，和redis插件一样使用，多增加一个ipdbpath参数指定ip2region xdb数据库路径

syntax

smartdns

redis loads authoritative zones from redis server

Address will default to local redis server (localhost:6379)

smartdns {
    address ADDR
    password PWD
    prefix PREFIX
    suffix SUFFIX
    connect_timeout TIMEOUT
    read_timeout TIMEOUT
    ttl TTL
    ipdbpath /smartcdn/ip2region.xdb
}

address is redis server address to connect in the form of host:port or ip:port.
password is redis server auth key
connect_timeout time in ms to wait for redis server to connect
read_timeout time in ms to wait for redis server to respond
ttl default ttl for dns records, 300 if not provided
prefix add PREFIX to all redis keys
suffix add SUFFIX to all redis keys

examples

. {
    redis example.com {
        address localhost:6379
        password foobared
        connect_timeout 100
        read_timeout 100
        ttl 360
        prefix _dns:
    }
}

reverse zones

reverse zones is not supported yet

proxy

proxy is not supported yet

zone format in redis db

zones

each zone is stored in redis as a hash map with zone as key

redis-cli>KEYS example*
1) "example.com."
2) "example.net."
redis-cli>

dns RRs

dns RRs are stored in redis as json strings inside a hash map using address as field key. @ is used for zone's own RR values.

A

{
  "a":[{
    "ip" : "1.2.3.4",
    "ttl" : 360
  }]
}

AAAA

{
  "aaaa":[{
    "ip" : "::1",
    "ttl" : 360
  }]
}

CNAME

{
  "cname":[{
    "host" : "x.example.com.",
    "ttl" : 360
  }]
}

TXT

{
  "txt":[{
    "text" : "this is a text",
    "ttl" : 360
  }]
}

NS

{
  "ns":[{
    "host" : "ns1.example.com.",
    "ttl" : 360
  }]
}

MX

{
  "mx":[{
    "host" : "mx1.example.com",
    "priority" : 10,
    "ttl" : 360
  }]
}

SRV

{
  "srv":[{
    "host" : "sip.example.com.",
    "port" : 555,
    "priority" : 10,
    "weight" : 100,
    "ttl" : 360
  }]
}

SOA

{
  "soa":[{
    "ttl" : 100,
    "mbox" : "hostmaster.example.com.",
    "ns" : "ns1.example.com.",
    "refresh" : 44,
    "retry" : 55,
    "expire" : 66
  }]
}

CAA

{
  "caa":[{
    "flag" : 0,
    "tag" : "issue",
    "value" : "letsencrypt.org"
  }]
}

example

$ORIGIN example.net.
 example.net.                 300 IN  SOA   <SOA RDATA>
 example.net.                 300     NS    ns1.example.net.
 example.net.                 300     NS    ns2.example.net.
 *.example.net.               300     TXT   "this is a wildcard"
 *.example.net.               300     MX    10 host1.example.net.
 sub.*.example.net.           300     TXT   "this is not a wildcard"
 host1.example.net.           300     A     5.5.5.5
 _ssh.tcp.host1.example.net.  300     SRV   <SRV RDATA>
 _ssh.tcp.host2.example.net.  300     SRV   <SRV RDATA>
 subdel.example.net.          300     NS    ns1.subdel.example.net.
 subdel.example.net.          300     NS    ns2.subdel.example.net.
 host2.example.net                    CAA   0 issue "letsencrypt.org"

above zone data should be stored at redis as follow:

1)  "@"
2)  "{"txt":[{"ttl":300,"text":"this is a wildcard 111"}],"mx":[{"ttl":300,"host":"host1.example.net.","preference":10}]}"
3)  "@:mx"
4)  "{"txt":[{"ttl":300,"text":"this is a wildcard 111"}],"mx":[{"ttl":300,"host":"host1.example.net.","preference":10},{"ttl":300,"host":"host2.example.net.","preference":10}]}"
5)  "sub_domain:a:smart:移动"
6)  "{"a":[{"ip":"2.2.2.2","ttl":360,"weight":10,"status":"ENABLE","line":"默认","line_id":"0","remark":""},{"ip":"3.3.3.3","ttl":360,"weight":10,"status":"ENABLE","line":"默认","line_id":"0","remark":""}]}"
7)  "sub_domain:a"
8)  "{"txt":[{"ttl":300,"text":"this is not a wildcard"}],"ns":[{"host":"ns1.example.com.","weight":100,"ttl":360},{"host":"ns2.example.com.","weight":100,"ttl":360}],"srv":[{"host":"sip.example.com.","port":555,"priority":10,"weight":100,"ttl":360}],"caa":[{"flag":0,"tag":"issue","weight":100,"value":"letsencrypt.org"}],"cname":[{"host":"x.example.com.","weight":100,"ttl":360}],"aaaa":[{"ip":"::1","weight":100,"ttl":360}],"a":[{"ip":"1.1.2.2","ttl":60,"weight":10,"status":"ENABLE","line":"默认","line_id":"0","remark":""},{"ip":"3.3.1.1","ttl":60,"weight":10,"status":"ENABLE","line":"默认","line_id":"0","remark":""}]}"
9)  "sub_domain:a:smart:阿里云:浙江省"
10) "{"txt":[{"ttl":300,"text":"this is not a wildcard"}],"a":[{"ip":"222.222.222.222","ttl":60,"weight":10,"status":"ENABLE","line":"默认","line_id":"0","remark":""},{"ip":"221.221.221.221","ttl":60,"weight":10,"status":"ENABLE","line":"默认","line_id":"0","remark":""}]}"
11) "@:mx:smart:联通:北京"
12) "{
  "txt": [
    {
      "ttl": 300,
      "text": "cnc beijing"
    }
  ],
  "mx": [
    {
      "ttl": 300,
      "host": "cnc1.example.net.",
      "preference": 10
    },
{
      "ttl": 300,
      "host": "cnc2.example.net.",
      "preference": 10
    }
  ]
}"
13) "sub"
14) "{"txt":[{"ttl":300,"text":"this is not a wildcard"}],"soa":{"ttl":100,"mbox":"hostmaster.example.com.","ns":"ns1.example.com.","refresh":44,"retry":55,"expire":66}}"
15) "_ssh._tcp.host1"
16) "{
    "srv": [
        {
            "ttl": 300,
            "target": "tcp.example.com.",
            "port": 123,
            "priority": 10,
            "weight": 100
        }
    ]
}"
17) "sub_domain:a:smart:联通:北京"
18) "{"txt":[{"ttl":300,"text":"this is not a wildcard"}],"a":[{"ip":"120.120.120.120","ttl":60,"weight":10,"status":"ENABLE","line":"默认","line_id":"0","remark":""},{"ip":"221.221.221.221","ttl":60,"weight":10,"status":"ENABLE","line":"默认","line_id":"0","remark":""}]}"

voilet/smartdns