本文同步發表 https://nevertired.nctu.me/2020/02/01/coredns-cloud-native-dns/

前面介紹過 MaraDNS

今天來說 CoreDNS

同樣支援跨平台、opensource

主打 Cloud Native DNS

其更過人的長處在於

MaraDNS 稍微有點複雜

CoreDNS 更進一步簡化

並支援 Plugins

想要什麼，就有什麼

CoreDNS 官網 https://coredns.io/

優點
節錄自 https://github.com/coredns/coredns

Serve zone data from a file; both DNSSEC (NSEC only) and DNS are supported (file and auto).
Retrieve zone data from primaries, i.e., act as a secondary server (AXFR only) (secondary).
Sign zone data on-the-fly (dnssec).
Load balancing of responses (loadbalance).
Allow for zone transfers, i.e., act as a primary server (file).
Automatically load zone files from disk (auto).
Caching of DNS responses (cache).
Use etcd as a backend (replacing SkyDNS) (etcd).
Use k8s (kubernetes) as a backend (kubernetes).
Serve as a proxy to forward queries to some other (recursive) nameserver (forward).
Provide metrics (by using Prometheus) (metrics).
Provide query (log) and error (errors) logging.
Integrate with cloud providers (route53).
Support the CH class: version.bind and friends (chaos).
Support the RFC 5001 DNS name server identifier (NSID) option (nsid).
Profiling support (pprof).
Rewrite queries (qtype, qclass and qname) (rewrite and template).
Block ANY queries (any).

開始使用
進入官網按下 Download 就會發現 CoreDNS 都已經編譯好各種平台了，貼心啊

以 windows 為例

下載後僅有一個執行檔

直接執行預設就有 whoami and log 兩個 plugins

建立 config
在同目錄下建立 Corefile

# 監聽 53 port 
.:53 {
    forward . 8.8.8.8:53
  
    errors
    log
}
# 建立 example.org domain
# 相關紀錄位於 db.example.org  格式請參考 https://docs.cloud.oracle.com/en-us/iaas/Content/DNS/Reference/formattingzonefile.htm
example.org {
    file db.example.org
  errors
    log
}

建立 db.example.org flie

格式請參考 RFC 1035 https://docs.cloud.oracle.com/en-us/iaas/Content/DNS/Reference/formattingzonefile.htm

example.org.   IN SOA dns.example.org. domains.example.org. (
    2012062701   ; serial
    300          ; refresh
    1800         ; retry
    14400        ; expire
    300 )        ; minimum
@                        IN NS      dns.example.com.
@                  42000 IN A       127.0.0.1
@                  42000 IN A       127.0.0.2
@                  42000 IN A       127.0.0.3
api                42000 IN CNAME   sample.service.dns.example.de.
www                42000 IN CNAME   sample.service.dns.example.de.
blog               42000 IN CNAME   sample.service.dns.example.de.
@                   3600 IN MX 1    ASPMX1.L.google.com.
@                   3600 IN MX 1    ASPMX2.L.google.com.
@                   3600 IN MX 1    ASPMX3.L.google.com.
@                    300 IN TXT     "v=spf1 include:_spf.google.com ~all"

執行、測試
.\coredns.exe
 

C:UsersNB>nslookup
> server 127.0.0.1
預設伺服器:  [127.0.0.1]
Address:  127.0.0.1
> example.org
伺服器:  [127.0.0.1]
Address:  127.0.0.1
名稱:    example.org
Addresses:  127.0.0.1
          127.0.0.2
          127.0.0.3