careyjames/dns-scout

package dnsinformation

import (
    "strings"

    "github.com/miekg/dns"
)

// QueryDNS performs a DNS query for a given domain and DNS record type.
func QueryDNS(domain string, dnsType uint16, server string) ([]string, error) {
    c := new(dns.Client)
    m := new(dns.Msg)
    m.SetQuestion(dns.Fqdn(domain), dnsType)

    r, _, err := c.Exchange(m, server)
    if err != nil {
        return nil, err
    }

    var records []string
    for _, ans := range r.Answer {
        switch t := ans.(type) {
        case *dns.NS:
            records = append(records, strings.TrimRight(t.Ns, "."))
        case *dns.MX:
            records = append(records, strings.TrimRight(t.Mx, "."))
        case *dns.TXT:
            records = append(records, t.Txt...)
        }
    }
    return records, nil
}