add DuckDNS support

README.md

@@ -33,6 +33,7 @@ Now I rewrite [DynDNS](https://github.com/TimothyYe/DynDNS) by Golang and call i
 * DNSPod ([https://www.dnspod.cn/](https://www.dnspod.cn/))
 * HE.net (Hurricane Electric) ([https://dns.he.net/](https://dns.he.net/))
 * AliDNS ([https://help.aliyun.com/product/29697.html](https://help.aliyun.com/product/29697.html))
+* DuckDNS ([https://www.duckdns.org](https://www.duckdns.org))
 
 ## Supported Platforms
 
@@ -201,6 +202,29 @@ For AliDNS, you need to provide `AccessKeyID` & `AccessKeySecret` as `email` & `
 }
 ```
 
+### Config example for DuckDNS
+
+For DuckDNS, only need to provide the `token`, config 1 default domain & subdomains.
+
+```json
+{
+  "provider": "DuckDNS",
+  "password": "",
+  "login_token": "3aaaaaaaa-f411-4198-a5dc-8381cac61b87",
+  "domains": [
+    {
+      "domain_name": "www.duckdns.org",
+      "sub_domains": [
+        "myname"
+      ]
+    }
+  ],
+  "ip_url": "https://myip.biturl.top",
+  "interval": 30,
+  "socks5_proxy": "",
+}
+```
+
 ### Config example for HE.net
 
 For HE, email is not needed, just fill DDNS key to password, and config all the domains & subdomains.

handler/duck/duck_handler.go

@@ -0,0 +1,103 @@
+package duck
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"runtime/debug"
+	"time"
+
+	"github.com/TimothyYe/godns"
+	"golang.org/x/net/proxy"
+)
+
+var (
+	// DuckUrl the API address for Duck DNS
+	DuckUrl = "https://www.duckdns.org/update?domains=%s&token=%s&ip=%s"
+)
+
+// Handler struct
+type Handler struct {
+	Configuration *godns.Settings
+}
+
+// SetConfiguration pass dns settings and store it to handler instance
+func (handler *Handler) SetConfiguration(conf *godns.Settings) {
+	handler.Configuration = conf
+}
+
+// DomainLoop the main logic loop
+func (handler *Handler) DomainLoop(domain *godns.Domain, panicChan chan<- godns.Domain) {
+	defer func() {
+		if err := recover(); err != nil {
+			log.Printf("Recovered in %v: %v\n", err, debug.Stack())
+			panicChan <- *domain
+		}
+	}()
+
+	var lastIP string
+
+	for {
+		currentIP, err := godns.GetCurrentIP(handler.Configuration)
+
+		if err != nil {
+			log.Println("get_currentIP:", err)
+			continue
+		}
+		log.Println("currentIP is:", currentIP)
+
+		//check against locally cached IP, if no change, skip update
+		if currentIP == lastIP {
+			log.Printf("IP is the same as cached one. Skip update.\n")
+		} else {
+			client := &http.Client{}
+
+			if handler.Configuration.Socks5Proxy != "" {
+				log.Println("use socks5 proxy:" + handler.Configuration.Socks5Proxy)
+				dialer, err := proxy.SOCKS5("tcp", handler.Configuration.Socks5Proxy, nil, proxy.Direct)
+				if err != nil {
+					log.Println("can't connect to the proxy:", err)
+					return
+				}
+
+				httpTransport := &http.Transport{}
+				client.Transport = httpTransport
+				httpTransport.Dial = dialer.Dial
+			}
+
+			for _, subDomain := range domain.SubDomains {
+				// update IP with HTTP GET request
+				resp, err := client.Get(fmt.Sprintf(DuckUrl, subDomain, handler.Configuration.LoginToken, currentIP))
+				if err != nil {
+					// handle error
+					log.Print("Failed to update sub domain:", subDomain)
+					continue
+				}
+
+				defer resp.Body.Close()
+
+				body, err := ioutil.ReadAll(resp.Body)
+				if err != nil || string(body) != "OK" {
+					// handle error
+					log.Print("Failed to update sub domain:", subDomain, err.Error())
+					continue
+				} else {
+					log.Print("IP updated to:", currentIP)
+				}
+
+				// Send mail notification if notify is enabled
+				if handler.Configuration.Notify.Enabled {
+					log.Print("Sending notification to:", handler.Configuration.Notify.SendTo)
+					if err := godns.SendNotify(handler.Configuration, fmt.Sprintf("%s.%s", subDomain, domain.DomainName), currentIP); err != nil {
+						log.Println("Failed to send notification")
+					}
+				}
+			}
+		}
+
+		// Sleep with interval
+		log.Printf("Going to sleep, will start next checking in %d seconds...\r\n", handler.Configuration.Interval)
+		time.Sleep(time.Second * time.Duration(handler.Configuration.Interval))
+	}
+}

handler/handler.go

@@ -5,6 +5,7 @@ import (
 	"github.com/TimothyYe/godns/handler/alidns"
 	"github.com/TimothyYe/godns/handler/cloudflare"
 	"github.com/TimothyYe/godns/handler/dnspod"
+	"github.com/TimothyYe/godns/handler/duck"
 	"github.com/TimothyYe/godns/handler/google"
 	"github.com/TimothyYe/godns/handler/he"
 )
@@ -30,6 +31,8 @@ func CreateHandler(provider string) IHandler {
 		handler = IHandler(&alidns.Handler{})
 	case godns.GOOGLE:
 		handler = IHandler(&google.Handler{})
+	case godns.DUCK:
+		handler = IHandler(&duck.Handler{})
 	}
 
 	return handler

utils.go

@@ -44,6 +44,8 @@ const (
 	ALIDNS = "AliDNS"
 	// GOOGLE for Google Domains
 	GOOGLE = "Google"
+	// DUCK for Duck DNS
+	DUCK = "DuckDNS"
 )
 
 //GetIPFromInterface gets IP address from the specific interface
@@ -187,8 +189,12 @@ func CheckSettings(config *Settings) error {
 		if config.Password == "" {
 			return errors.New("password cannot be empty")
 		}
+	} else if config.Provider == DUCK {
+		if config.LoginToken == "" {
+			return errors.New("login token cannot be empty")
+		}
 	} else {
-		return errors.New("please provide supported DNS provider: DNSPod/HE")
+		return errors.New("please provide supported DNS provider: DNSPod/HE/AliDNS/Cloudflare/GoogleDomain/DuckDNS")
 	}
 
 	return nil