resolver

go-dns-resolver

DNS resolver in Golang, based on miekg/dns.

Goal

1. Simple interface
2. Rich and neat output
3. Easy to figure
4. High performance

Install

go get github.com/Focinfi/go-dns-resolver

Example

package main

import (
  dns "github.com/Focinfi/go-dns-resolver"
  "log"
)

func main() {
  domains := []string{"google.com", "twitter.com"}
  types := []dns.QueryType{dns.TypeA, dns.TypeNS, dns.TypeMX, dns.TypeTXT}

  // Set timeout and retry times
  dns.Config.SetTimeout(uint(2))
  dns.Config.RetryTimes = uint(4)

  // Simple usage
  if results, err := dns.Exchange("google.com", "119.29.29.29", dns.TypeA); err == nil {
    for _, r := range results {
      log.Println(r.Record, r.Type, r.Ttl, r.Priority, r.Content)
    }
  } else {
    log.Fatal(err)
  }

  // Create and setup resolver with domains and types
  resolver := dns.NewResolver("119.29.29.29")
  resolver.Targets(domains...).Types(types...)
  // Lookup
  res := resolver.Lookup()

  //res.ResMap is a map[string]*ResultItem, key is the domain
  for target := range res.ResMap {
    log.Printf("%v: \n", target)
    for _, r := range res.ResMap[target] {
      log.Println(r.Record, r.Type, r.Ttl, r.Priority, r.Content)
    }
  }
}

Output:

google.com A 2m31s 0 216.58.197.110

twitter.com: 
twitter.com A 10m3s 0 78.16.49.15
twitter.com NS 11h49m58s 0 ns1.p34.dynect.net.
twitter.com NS 11h49m58s 0 ns4.p34.dynect.net.
twitter.com NS 11h49m58s 0 ns3.p34.dynect.net.
twitter.com NS 11h49m58s 0 ns2.p34.dynect.net.
google.com: 
google.com TXT 19m26s 0 v=spf1 include:_spf.google.com ~all
google.com A 2m31s 0 216.58.197.110
google.com NS 7h40m6s 0 ns1.google.com.
google.com NS 7h40m6s 0 ns3.google.com.
google.com NS 7h40m6s 0 ns2.google.com.
google.com NS 7h40m6s 0 ns4.google.com.
google.com MX 10m0s 20 alt1.aspmx.l.google.com.
google.com MX 10m0s 10 aspmx.l.google.com.
google.com MX 10m0s 50 alt4.aspmx.l.google.com.
google.com MX 10m0s 40 alt3.aspmx.l.google.com.
google.com MX 10m0s 30 alt2.aspmx.l.google.com.
[Finished in 2.3s]

Todo

1. Support more DNS record types