pancheri/resolver.go

package pancheri

import (
	"github.com/miekg/dns"
	"github.com/sirupsen/logrus"
)

type Resolver struct {
	client   *dns.Client
	upstream string
}

func NewResolver(upstream string) *Resolver {
	return &Resolver{
		client:   new(dns.Client),
		upstream: upstream,
	}
}

func (r *Resolver) Resolve(domain string, qtype uint16) ([]dns.RR, int, error) {
	logrus.WithFields(logrus.Fields{
		"domain": domain,
		"qtype":  qtype,
	}).Trace("performing upstream resolution")

	m := new(dns.Msg)
	m.SetQuestion(dns.Fqdn(domain), qtype)
	m.RecursionDesired = true

	in, _, err := r.client.Exchange(m, r.upstream)

	if err != nil {
		return nil, err
	}

	return in.Answer, in.Rcode, nil
}