lego/providers/dns/duckdns/client.go
2020-05-08 19:35:25 +02:00

68 lines
1.7 KiB
Go

package duckdns
import (
"fmt"
"io/ioutil"
"net/url"
"strconv"
"strings"
"github.com/go-acme/lego/v3/challenge/dns01"
"github.com/miekg/dns"
)
// updateTxtRecord Update the domains TXT record
// To update the TXT record we just need to make one simple get request.
// In DuckDNS you only have one TXT record shared with the domain and all sub domains.
func (d *DNSProvider) updateTxtRecord(domain, token, txt string, clear bool) error {
u, _ := url.Parse("https://www.duckdns.org/update")
mainDomain := getMainDomain(domain)
if len(mainDomain) == 0 {
return fmt.Errorf("unable to find the main domain for: %s", domain)
}
query := u.Query()
query.Set("domains", mainDomain)
query.Set("token", token)
query.Set("clear", strconv.FormatBool(clear))
query.Set("txt", txt)
u.RawQuery = query.Encode()
response, err := d.config.HTTPClient.Get(u.String())
if err != nil {
return err
}
defer response.Body.Close()
bodyBytes, err := ioutil.ReadAll(response.Body)
if err != nil {
return err
}
body := string(bodyBytes)
if body != "OK" {
return fmt.Errorf("request to change TXT record for DuckDNS returned the following result (%s) this does not match expectation (OK) used url [%s]", body, u)
}
return nil
}
// DuckDNS only lets you write to your subdomain.
// It must be in format subdomain.duckdns.org,
// not in format subsubdomain.subdomain.duckdns.org.
// So strip off everything that is not top 3 levels.
func getMainDomain(domain string) string {
domain = dns01.UnFqdn(domain)
split := dns.Split(domain)
if strings.HasSuffix(strings.ToLower(domain), "duckdns.org") {
if len(split) < 3 {
return ""
}
firstSubDomainIndex := split[len(split)-3]
return domain[firstSubDomainIndex:]
}
return domain[split[len(split)-1]:]
}