coredns-redis: A Go repository from arthurkay

redis enables reading zone data from redis database. this plugin should be located right next to etcd in plugins.cfg

syntax

redis

redis loads authoritative zones from redis server

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

redis {
    address ADDR
    password PWD
    prefix PREFIX
    suffix SUFFIX
    connect_timeout TIMEOUT
    read_timeout TIMEOUT
    ttl TTL
    zone_update_time UPDATE_TIME
}

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
zone_update_time Time in seconds to check for new zones

examples

. {
    redis example.com {
        address localhost:6379
        password foobared
        connect_timeout 100
        read_timeout 100
        ttl 360
        prefix _dns:
        zone_update_time 10
    }
}

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 *
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:

redis-cli> hgetall example.net.
 1) "_ssh._tcp.host1"
 2) "{\"srv\":[{\"ttl\":300, \"target\":\"tcp.example.com.\",\"port\":123,\"priority\":10,\"weight\":100}]}"
 3) "*"
 4) "{\"txt\":[{\"ttl\":300, \"text\":\"this is a wildcard\"}],\"mx\":[{\"ttl\":300, \"host\":\"host1.example.net.\",\"preference\": 10}]}"
 5) "host1"
 6) "{\"a\":[{\"ttl\":300, \"ip\":\"5.5.5.5\"}]}"
 7) "sub.*"
 8) "{\"txt\":[{\"ttl\":300, \"text\":\"this is not a wildcard\"}]}"
 9) "_ssh._tcp.host2"
10) "{\"srv\":[{\"ttl\":300, \"target\":\"tcp.example.com.\",\"port\":123,\"priority\":10,\"weight\":100}]}"
11) "subdel"
12) "{\"ns\":[{\"ttl\":300, \"host\":\"ns1.subdel.example.net.\"},{\"ttl\":300, \"host\":\"ns2.subdel.example.net.\"}]}"
13) "@"
14) "{\"soa\":{\"ttl\":300, \"minttl\":100, \"mbox\":\"hostmaster.example.net.\",\"ns\":\"ns1.example.net.\",\"refresh\":44,\"retry\":55,\"expire\":66},\"ns\":[{\"ttl\":300, \"host\":\"ns1.example.net.\"},{\"ttl\":300, \"host\":\"ns2.example.net.\"}]}"
15) "host2"
16)"{\"caa\":[{\"flag\":0, \"tag\":\"issue\", \"value\":\"letsencrypt.org\"}]}"
redis-cli>

arthurkay/coredns-redis