lego/providers/dns/duckdns/internal/client.go
2023-05-05 09:49:38 +02:00

103 lines
2.6 KiB
Go

package internal
import (
"context"
"fmt"
"io"
"net/http"
"net/url"
"strconv"
"strings"
"time"
"github.com/go-acme/lego/v4/challenge/dns01"
"github.com/go-acme/lego/v4/providers/dns/internal/errutils"
"github.com/miekg/dns"
)
const defaultBaseURL = "https://www.duckdns.org/update"
// Client the DuckDNS API client.
type Client struct {
token string
HTTPClient *http.Client
}
// NewClient Creates a new Client.
func NewClient(token string) *Client {
return &Client{
token: token,
HTTPClient: &http.Client{Timeout: 5 * time.Second},
}
}
func (c Client) AddTXTRecord(ctx context.Context, domain, value string) error {
return c.UpdateTxtRecord(ctx, domain, value, false)
}
func (c Client) RemoveTXTRecord(ctx context.Context, domain string) error {
return c.UpdateTxtRecord(ctx, domain, "", true)
}
// 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 subdomains.
func (c Client) UpdateTxtRecord(ctx context.Context, domain, txt string, clear bool) error {
endpoint, _ := url.Parse(defaultBaseURL)
mainDomain := getMainDomain(domain)
if mainDomain == "" {
return fmt.Errorf("unable to find the main domain for: %s", domain)
}
query := endpoint.Query()
query.Set("domains", mainDomain)
query.Set("token", c.token)
query.Set("clear", strconv.FormatBool(clear))
query.Set("txt", txt)
endpoint.RawQuery = query.Encode()
req, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint.String(), http.NoBody)
if err != nil {
return fmt.Errorf("unable to create request: %w", err)
}
resp, err := c.HTTPClient.Do(req)
if err != nil {
return errutils.NewHTTPDoError(req, err)
}
defer func() { _ = resp.Body.Close() }()
raw, err := io.ReadAll(resp.Body)
if err != nil {
return errutils.NewReadResponseError(req, resp.StatusCode, err)
}
body := string(raw)
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, endpoint)
}
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]:]
}