lego/providers/dns/duckdns/duckdns.go
Ludovic Fernandez 1d1b08ac15
enhance the WithLiveTestRequirements algorithm (#681)
* refactor: migrate test to envTest.

* refactor: enforce WithLiveTestRequirements logic.

* chore: remove gometalinter.

* fix: godoc.

* doc: add Docker badge.
2018-10-18 22:32:00 +02:00

148 lines
4.3 KiB
Go

// Package duckdns implements a DNS provider for solving the DNS-01 challenge using DuckDNS.
// See http://www.duckdns.org/spec.jsp for more info on updating TXT records.
package duckdns
import (
"errors"
"fmt"
"io/ioutil"
"net/http"
"net/url"
"strconv"
"strings"
"time"
"github.com/miekg/dns"
"github.com/xenolf/lego/acme"
"github.com/xenolf/lego/platform/config/env"
)
// Config is used to configure the creation of the DNSProvider
type Config struct {
Token string
PropagationTimeout time.Duration
PollingInterval time.Duration
HTTPClient *http.Client
}
// NewDefaultConfig returns a default configuration for the DNSProvider
func NewDefaultConfig() *Config {
client := acme.HTTPClient
client.Timeout = env.GetOrDefaultSecond("DUCKDNS_HTTP_TIMEOUT", 30*time.Second)
return &Config{
PropagationTimeout: env.GetOrDefaultSecond("DUCKDNS_PROPAGATION_TIMEOUT", acme.DefaultPropagationTimeout),
PollingInterval: env.GetOrDefaultSecond("DUCKDNS_POLLING_INTERVAL", acme.DefaultPollingInterval),
HTTPClient: &client,
}
}
// DNSProvider adds and removes the record for the DNS challenge
type DNSProvider struct {
config *Config
}
// NewDNSProvider returns a new DNS provider using
// environment variable DUCKDNS_TOKEN for adding and removing the DNS record.
func NewDNSProvider() (*DNSProvider, error) {
values, err := env.Get("DUCKDNS_TOKEN")
if err != nil {
return nil, fmt.Errorf("duckdns: %v", err)
}
config := NewDefaultConfig()
config.Token = values["DUCKDNS_TOKEN"]
return NewDNSProviderConfig(config)
}
// NewDNSProviderCredentials uses the supplied credentials
// to return a DNSProvider instance configured for http://duckdns.org
// Deprecated
func NewDNSProviderCredentials(token string) (*DNSProvider, error) {
config := NewDefaultConfig()
config.Token = token
return NewDNSProviderConfig(config)
}
// NewDNSProviderConfig return a DNSProvider instance configured for DuckDNS.
func NewDNSProviderConfig(config *Config) (*DNSProvider, error) {
if config == nil {
return nil, errors.New("duckdns: the configuration of the DNS provider is nil")
}
if config.Token == "" {
return nil, errors.New("duckdns: credentials missing")
}
return &DNSProvider{config: config}, nil
}
// Present creates a TXT record to fulfill the dns-01 challenge.
func (d *DNSProvider) Present(domain, token, keyAuth string) error {
_, txtRecord, _ := acme.DNS01Record(domain, keyAuth)
return updateTxtRecord(domain, d.config.Token, txtRecord, false)
}
// CleanUp clears DuckDNS TXT record
func (d *DNSProvider) CleanUp(domain, token, keyAuth string) error {
return updateTxtRecord(domain, d.config.Token, "", true)
}
// Timeout returns the timeout and interval to use when checking for DNS propagation.
// Adjusting here to cope with spikes in propagation times.
func (d *DNSProvider) Timeout() (timeout, interval time.Duration) {
return d.config.PropagationTimeout, d.config.PollingInterval
}
// 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 updateTxtRecord(domain, token, txt string, clear bool) error {
u, _ := url.Parse("https://www.duckdns.org/update")
query := u.Query()
query.Set("domains", getMainDomain(domain))
query.Set("token", token)
query.Set("clear", strconv.FormatBool(clear))
query.Set("txt", txt)
u.RawQuery = query.Encode()
response, err := acme.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 = acme.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]:]
}