Example code to query dns to cloudflare-dns.com

dns_over_https.go

package main

import (
	"encoding/json"
	"log"
	"fmt"
	"net/http"
)

type DNSQuestion struct {
	Name	string	`json:"name"`
	Type	int		`json:"type"`
}

type DNSAnswer struct {
	Name	string	`json:"name"`
	Type	int		`json:"type"`
	TTL		int		`json:"TTL"`
	Data	string	`json:"data"`
}

type DNSResponse struct {
	Status		int				`json:"Status"`
	TC			bool			`json:"TC"`
	RD			bool			`json:"RD"`
	RA			bool			`json:"RA"`
	AD			bool			`json:"AD"`
	CD			bool			`json:"CD"`
	Question	[]DNSQuestion	`json"Question"`
	Answer		[]DNSAnswer		`json"Question"`
}

func Lookup(name, qtype string) (*DNSResponse, error) {
	url := fmt.Sprintf(
		"https://cloudflare-dns.com/dns-query?name=%s&type=%s",
		name,
		qtype,
	)

	req, err := http.NewRequest("GET", url, nil)
	if err != nil {
		return nil, err
	}
	req.Header.Set("Accept", "application/dns-json")

	client := &http.Client{}

	res, err := client.Do(req)
	if err != nil {
		return nil, err
	}
	var response DNSResponse
	if err := json.NewDecoder(res.Body).Decode(&response); err != nil {
		return nil, err
	}
	defer res.Body.Close()

	return &response, nil
}

func main() {
	response, err := Lookup("www.google.com", "A")
	if err != nil {
		log.Fatalln(err)
	}
	log.Printf("Status: %d, Name: %s, LenOfAnswers: %d", response.Status, response.Question[0].Name, len(response.Answer))
	for _, answer := range response.Answer {
		log.Printf("Data: %s", answer.Data)
	}
}