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 // so 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]:] }