add DuckDNS support

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))
+	}
+}