Merge remote-tracking branch 'upstream/master'

2025-01-18 04:03:25 -08:00 · 2018-07-04 10:52:50 +08:00 · 2018-07-04 10:52:50 +08:00 · 5344c3c393
commit 5344c3c393
parent 0723452a66 b919752145
24 changed files with 976 additions and 800 deletions
--- a/.gitignore
+++ b/.gitignore
@ -28,10 +28,13 @@ _testmain.go
 config.json
 *.log
 *.swp
-godns
+*.gz
+cmd/godns/godns

 vendor/*
 /.idea
 /godns.iml
 /godns.ipr
 /godns.iws
+.current_ip
+.DS_Store
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@ -1,24 +0,0 @@
-before_script:
-  - export GOPATH=$(pwd)
-  - export GOBIN=$GOPATH/bin
-
-stages:
-  - build
-  - test
-
-build-my-project:
-  image: golang:1.6.2
-  stage: build
-  script:
-    - mkdir $GOPATH/bin
-    - go get
-    - go build
-
-test-my-project:
-  image: golang:1.6.2
-  stage: test
-  script:
-    - mkdir $GOPATH/bin
-    - go get
-    - go build
-    - go test
--- a/.travis.yml
+++ b/.travis.yml
@ -1,7 +1,13 @@
 language: go
 go: 
- - 1.7
- - 1.8
+ - 1.7.x
+ - 1.8.x
+ - 1.9.x
+
+install:
+ - go get -v
+ - go get -v github.com/bitly/go-simplejson
+ - go get -v github.com/fatih/color

 script:
 - cp ./config_sample.json ./config.json
--- a/README.md
+++ b/README.md
@ -5,25 +5,52 @@
 ██║   ██║██║   ██║██║  ██║██║╚██╗██║╚════██║
 ╚██████╔╝╚██████╔╝██████╔╝██║ ╚████║███████║
 ╚═════╝  ╚═════╝ ╚═════╝ ╚═╝  ╚═══╝╚══════╝
-
-Latest release: V1.1
 ```

-[![Build Status](https://travis-ci.org/TimothyYe/godns.svg?branch=master)](https://travis-ci.org/TimothyYe/godns)
+[![Release][7]][8] [![MIT licensed][9]][10] [![Build Status][1]][2] [![Docker][3]][4] [![Go Report Card][11]][12] [![Cover.Run][15]][16] [![GoDoc][13]][14]

-GoDNS is a dynamic DNS (DDNS) tool, it is based on my early open source project: [DynDNS](https://github.com/TimothyYe/DynDNS). 
+[1]: https://travis-ci.org/TimothyYe/godns.svg?branch=master
+[2]: https://travis-ci.org/TimothyYe/godns
+[3]: https://images.microbadger.com/badges/image/timothyye/godns.svg
+[4]: https://microbadger.com/images/timothyye/godns
+[7]: http://github-release-version.herokuapp.com/github/timothyye/godns/release.svg?style=flat
+[8]: https://github.com/TimothyYe/godns/releases
+[9]: https://img.shields.io/badge/license-Apache-blue.svg
+[10]: LICENSE
+[11]: https://goreportcard.com/badge/github.com/timothyye/godns
+[12]: https://goreportcard.com/report/github.com/timothyye/godns
+[13]: https://godoc.org/github.com/TimothyYe/godns?status.svg
+[14]: https://godoc.org/github.com/TimothyYe/godns
+[15]: https://img.shields.io/badge/cover.run-88.2%25-green.svg
+[16]: https://cover.run/go/github.com/timothyye/godns
+
+GoDNS is a dynamic DNS (DDNS) client tool, it is based on my early open source project: [DynDNS](https://github.com/TimothyYe/DynDNS). 

 Now I rewrite [DynDNS](https://github.com/TimothyYe/DynDNS) by Golang and call it [GoDNS](https://github.com/TimothyYe/godns).

+## Supported DNS Provider
+* DNSPod ([https://www.dnspod.cn/](https://www.dnspod.cn/))
+* HE.net (Hurricane Electric) ([https://dns.he.net/](https://dns.he.net/))
+
+## Supported Platforms
+* Linux
+* MacOS
+* ARM Linux (Raspberry Pi, etc...)
+* Windows
+
+## MIPS32 platform
+
+For MIPS32 platform, please checkout the [mips32](https://github.com/TimothyYe/godns/tree/mips32) branch, this branch is contributed by [hguandl](https://github.com/hguandl), in this branch, the support for mips32 is added, which means it could run properly on Openwrt and LEDE.
+
 ## Pre-condition

-* GoDNS relies on [DNSPod](http://dnspod.cn) and its API. 
+* Register and own a domain.

-* To use GoDNS, you need a domain hosted on [DNSPod](http://dnspod.cn).
+* Domain's nameserver points to [DNSPod](https://www.dnspod.cn/) or [HE.net](https://dns.he.net/).

-## Build it
+## Get it

-### Get & build it from source code
+### Build it from source code

 * Get source code from Github:

@ -33,11 +60,15 @@ git clone https://github.com/timothyye/godns.git
 * Go into the godns directory, get related library and then build it:

 ```bash
-cd godns
-go get
+cd cmd/godns
+go get -v
 go build
 ```

+### Download from releases
+
+Download compiled binaries from [releases](https://github.com/TimothyYe/godns/releases)
+
 ## Get help

 ```bash
@ -53,11 +84,100 @@ Usage of ./godns:

 * Get [config_sample.json](https://github.com/timothyye/godns/blob/master/config_sample.json) from Github.
 * Rename it to **config.json**.
-* Configure your domain/sub-domain info, username and password of DNSPod account.
-* Configure log file path, max size of log file, max count of log file.
-* Configure user id, group id for safety.
+* Configure your provider, domain/sub-domain info, username and password, etc.
+* Configure the SMTP options if you want, a mail notification will sent to your mailbox once the IP is changed.
 * Save it in the same directory of GoDNS, or use -c=your_conf_path command.

+### Config example for DNSPod
+
+For DNSPod, you need to provide email & password,  and config all the domains & subdomains.
+
+```json
+{
+  "provider": "DNSPod",
+  "email": "example@gmail.com",
+  "password": "YourPassword",
+  "login_token": "",
+  "domains": [{
+      "domain_name": "example.com",
+      "sub_domains": ["www","test"]
+    },{
+      "domain_name": "example2.com",
+      "sub_domains": ["www","test"]
+    }
+  ],
+  "ip_url": "http://members.3322.org/dyndns/getip",
+  "log_path": "./godns.log",
+  "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.
+
+```json
+{
+  "provider": "HE",
+  "email": "",
+  "password": "YourPassword",
+  "login_token": "",
+  "domains": [{
+      "domain_name": "example.com",
+      "sub_domains": ["www","test"]
+    },{
+      "domain_name": "example2.com",
+      "sub_domains": ["www","test"]
+    }
+  ],
+  "ip_url": "http://members.3322.org/dyndns/getip",
+  "log_path":"/users/timothy/workspace/src/godns/godns.log",
+  "socks5_proxy": ""
+}
+```
+
+### HE.net DDNS configuration
+
+Add a new "A record", make sure that "Enable entry for dynamic dns" is checked:
+
+<img src="https://github.com/TimothyYe/godns/blob/master/snapshots/he1.png?raw=true" width="640" />
+
+Fill your own DDNS key or generate a random DDNS key for this new created "A record":
+
+<img src="https://github.com/TimothyYe/godns/blob/master/snapshots/he2.png?raw=true" width="640" />
+
+Remember the DDNS key and fill it as password to the config.json.
+
+__NOTICE__: If you have multiple domains or subdomains, make sure their DDNS key are the same.
+
+### Email notification support
+
+Update config file and provide your SMTP options, a notification mail will be sent to your mailbox once the IP is changed and updated.  
+
+```json
+  "notify": {
+    "enabled": true,
+    "smtp_server": "smtp.example.com",
+    "smtp_username": "user",
+    "smtp_password": "password",
+    "smtp_port": 25,
+    "send_to": "my_mail@example.com"
+  }
+```
+
+Notification mail example:  
+
+<img src="https://github.com/TimothyYe/godns/blob/master/snapshots/mail.png?raw=true" />  
+
+### SOCKS5 proxy support
+
+You can also use SOCKS5 proxy, just fill SOCKS5 address to the ```socks5_proxy``` item:
+
+```json
+"socks5_proxy": "127.0.0.1:7070"
+```
+
+Now all the queries will go through the specified SOCKS5 proxy.
+
 ## Run it as a daemon manually

 ```bash
@ -85,24 +205,17 @@ sudo systemctl enable godns
 sudo systemctl start godns
 ```

-## Run it in docker
+## Run it with docker

 Now godns supports to run in docker.

-* Pull godns image from docker hub:
-```bash
-docker pull timothyye/godns:1.0
-```
-
-* Run godns in container and pass config parameters to it via enviroment variables:
+* Get [config_sample.json](https://github.com/timothyye/godns/blob/master/config_sample.json) from Github.
+* Rename it to **config.json**.
+* Run GoDNS with docker:

 ```bash
 docker run -d --name godns --restart=always \
-e EMAIL=your_dnspod_account \
-e PASSWORD=your_dnspod_password \
-e DOMAINS="your_domain1,your_domain2" DOCKER_IMAGE_ID                                                                                              
+-v /path/to/config.json:/usr/local/godns/config.json timothyye/godns:latest
 ```

-
-
 ## Enjoy it!
--- a/cmd/godns/Dockerfile
+++ b/cmd/godns/Dockerfile
@ -1,4 +1,4 @@
-FROM alpine:latest
+FROM timothyye/alpine:3.6-glibc
 MAINTAINER Timothy
 RUN apk add --update ca-certificates
 RUN mkdir -p /usr/local/godns
@ -6,4 +6,4 @@ COPY godns /usr/local/godns
 RUN chmod +x /usr/local/godns/godns
 RUN rm -rf /var/cache/apk/*
 WORKDIR /usr/local/godns
-ENTRYPOINT ["./godns", "-d"]
+ENTRYPOINT ["./godns", "-c", "/usr/local/godns/config.json"]
--- a/cmd/godns/Makefile
+++ b/cmd/godns/Makefile
@ -0,0 +1,34 @@
+# Binary name
+BINARY=godns
+# Builds the project
+build:
+		go build -o ${BINARY} -ldflags "-X main.Version=${VERSION}"
+# Installs our project: copies binaries
+install:
+		go install
+release:
+		# Clean
+		go clean
+		rm -rf *.gz
+		# Build for mac
+		go build -o ${BINARY} -ldflags "-X main.Version=${VERSION}"
+		tar czvf ${BINARY}-mac64-${VERSION}.tar.gz ./${BINARY}
+		# Build for linux
+		go clean
+		CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o ${BINARY} -ldflags "-X main.Version=${VERSION}"
+		tar czvf ${BINARY}-linux64-${VERSION}.tar.gz ./${BINARY}
+		# Build for arm
+		go clean
+		CGO_ENABLED=0 GOOS=linux GOARCH=arm64 go build -o ${BINARY} -ldflags "-X main.Version=${VERSION}"
+		tar czvf ${BINARY}-arm64-${VERSION}.tar.gz ./${BINARY}
+		# Build for win
+		go clean
+		CGO_ENABLED=0 GOOS=windows GOARCH=amd64 go build -o ${BINARY}.exe -ldflags "-X main.Version=${VERSION}"
+		tar czvf ${BINARY}-win64-${VERSION}.tar.gz ./${BINARY}.exe
+		go clean
+# Cleans our projects: deletes binaries
+clean:
+		go clean
+		rm -rf *.gz
+
+.PHONY:  clean build
--- a/cmd/godns/godns.go
+++ b/cmd/godns/godns.go
@ -0,0 +1,70 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+
+	"log"
+
+	"github.com/TimothyYe/godns"
+	"github.com/TimothyYe/godns/handler"
+	"github.com/fatih/color"
+)
+
+var (
+	configuration godns.Settings
+	optConf       = flag.String("c", "./config.json", "Specify a config file")
+	optHelp       = flag.Bool("h", false, "Show help")
+
+	// Version is current version of GoDNS
+	Version = "0.1"
+)
+
+func main() {
+	flag.Parse()
+	if *optHelp {
+		color.Cyan(godns.Logo, Version)
+		flag.Usage()
+		return
+	}
+
+	// Load settings from configurations file
+	if err := godns.LoadSettings(*optConf, &configuration); err != nil {
+		fmt.Println(err.Error())
+		os.Exit(1)
+	}
+
+	if err := godns.CheckSettings(&configuration); err != nil {
+		fmt.Println("Settings is invalid! ", err.Error())
+		os.Exit(1)
+	}
+
+	// Init log settings
+	log.SetPrefix("【GoDNS】")
+	log.Println("GoDNS started, entering main loop...")
+	dnsLoop()
+}
+
+func dnsLoop() {
+	panicChan := make(chan godns.Domain)
+
+	log.Println("Creating DNS handler with provider:", configuration.Provider)
+	handler := handler.CreateHandler(configuration.Provider)
+	handler.SetConfiguration(&configuration)
+	for i, _ := range configuration.Domains {
+		go handler.DomainLoop(&configuration.Domains[i], panicChan)
+	}
+
+	panicCount := 0
+	for {
+		failDomain := <-panicChan
+		log.Println("Got panic in goroutine, will start a new one... :", panicCount)
+		go handler.DomainLoop(&failDomain, panicChan)
+
+		panicCount++
+		if panicCount >= godns.PanicMax {
+			os.Exit(1)
+		}
+	}
+}
--- a/config_sample.json
+++ b/config_sample.json
@ -1,17 +1,32 @@
 {
+  "provider": "DNSPod",
  "email": "example@gmail.com",
  "password": "",
  "login_token": "",
-  "domains": [{
+  "domains": [
+    {
      "domain_name": "example.com",
-      "sub_domains":["www","test"]
-    },{
+      "sub_domains": [
+        "www",
+        "test"
+      ]
+    },
+    {
      "domain_name": "example2.com",
-      "sub_domains":["www","test"]
+      "sub_domains": [
+        "www",
+        "test"
+      ]
    }
  ],
  "ip_url": "http://members.3322.org/dyndns/getip",
-  "log_path":"./godns.log",
-  "log_size":16,
-  "log_num":3
+  "socks5_proxy": "",
+  "notify": {
+    "enabled": false,
+    "smtp_server": "",
+    "smtp_username": "",
+    "smtp_password": "",
+    "smtp_port": 25,
+    "send_to": ""
+  }
 }
--- a/dns_handler.go
+++ b/dns_handler.go
@ -1,213 +0,0 @@
-package main
-
-import (
-	"encoding/json"
-	"fmt"
-	"io/ioutil"
-	"log"
-	"net/http"
-	"net/url"
-	"strconv"
-	"strings"
-	"golang.org/x/net/proxy"
-	"github.com/bitly/go-simplejson"
-)
-
-func getCurrentIP(url string) (string, error) {
-	response, err := http.Get(url)
-
-	if err != nil {
-		log.Println("Cannot get IP...")
-		return "", err
-	}
-
-	defer response.Body.Close()
-
-	body, _ := ioutil.ReadAll(response.Body)
-	return string(body), nil
-}
-
-func generateHeader(content url.Values) url.Values {
-	header := url.Values{}
-	if configuration.LoginToken != "" {
-		header.Add("login_token", configuration.LoginToken)
-	} else {
-		header.Add("login_email", configuration.Email)
-		header.Add("login_password", configuration.Password)
-	}
-	header.Add("format", "json")
-	header.Add("lang", "en")
-	header.Add("error_on_empty", "no")
-
-	if content != nil {
-		for k, _ := range content {
-			header.Add(k, content.Get(k))
-		}
-	}
-
-	return header
-}
-
-func apiVersion() {
-	postData("/Info.Version", nil)
-}
-
-func getDomain(name string) int64 {
-
-	var ret int64
-	values := url.Values{}
-	values.Add("type", "all")
-	values.Add("offset", "0")
-	values.Add("length", "20")
-
-	response, err := postData("/Domain.List", values)
-
-	if err != nil {
-		log.Println("Failed to get domain list...")
-		return -1
-	}
-
-	sjson, parseErr := simplejson.NewJson([]byte(response))
-
-	if parseErr != nil {
-		log.Println(parseErr)
-		return -1
-	}
-
-	if sjson.Get("status").Get("code").MustString() == "1" {
-		domains, _ := sjson.Get("domains").Array()
-
-		for _, d := range domains {
-			m := d.(map[string]interface{})
-			if m["name"] == name {
-				id := m["id"]
-
-				switch t := id.(type) {
-				case json.Number:
-					ret, _ = t.Int64()
-				}
-
-				break
-			}
-		}
-		if len(domains) == 0 {
-			log.Println("domains slice is empty.")
-		}
-	} else {
-		log.Println("get_domain:status code:", sjson.Get("status").Get("code").MustString())
-	}
-
-	return ret
-}
-
-func getSubDomain(domainID int64, name string) (string, string) {
-	log.Println("debug:", domainID, name)
-	var ret, ip string
-	value := url.Values{}
-	value.Add("domain_id", strconv.FormatInt(domainID, 10))
-	value.Add("offset", "0")
-	value.Add("length", "1")
-	value.Add("sub_domain", name)
-
-	response, err := postData("/Record.List", value)
-
-	if err != nil {
-		log.Println("Failed to get domain list")
-		return "", ""
-	}
-
-	sjson, parseErr := simplejson.NewJson([]byte(response))
-
-	if parseErr != nil {
-		log.Println(parseErr)
-		return "", ""
-	}
-
-	if sjson.Get("status").Get("code").MustString() == "1" {
-		records, _ := sjson.Get("records").Array()
-
-		for _, d := range records {
-			m := d.(map[string]interface{})
-			if m["name"] == name {
-				ret = m["id"].(string)
-				ip = m["value"].(string)
-				break
-			}
-		}
-		if len(records) == 0 {
-			log.Println("records slice is empty.")
-		}
-	} else {
-		log.Println("get_subdomain:status code:", sjson.Get("status").Get("code").MustString())
-	}
-
-	return ret, ip
-}
-
-func updateIP(domainID int64, subDomainID string, subDomainName string, ip string) {
-	value := url.Values{}
-	value.Add("domain_id", strconv.FormatInt(domainID, 10))
-	value.Add("record_id", subDomainID)
-	value.Add("sub_domain", subDomainName)
-	value.Add("record_type", "A")
-	value.Add("record_line", "默认")
-	value.Add("value", ip)
-
-	response, err := postData("/Record.Modify", value)
-
-	if err != nil {
-		log.Println("Failed to update record to new IP!")
-		log.Println(err)
-		return
-	}
-
-	sjson, parseErr := simplejson.NewJson([]byte(response))
-
-	if parseErr != nil {
-		log.Println(parseErr)
-		return
-	}
-
-	if sjson.Get("status").Get("code").MustString() == "1" {
-		log.Println("New IP updated!")
-	}
-
-}
-
-func postData(url string, content url.Values) (string, error) {
-	client := &http.Client{}
-
-	if configuration.Socks5Proxy != "" {
-
-		log.Println("use socks5 proxy:" + configuration.Socks5Proxy)
-
-		dialer, err := proxy.SOCKS5("tcp", configuration.Socks5Proxy, nil, proxy.Direct)
-		if err != nil {
-			fmt.Println("can't connect to the proxy:", err)
-			return "", err
-		}
-
-		httpTransport := &http.Transport{}
-		client.Transport = httpTransport
-		httpTransport.Dial = dialer.Dial
-	}
-
-	values := generateHeader(content)
-	req, _ := http.NewRequest("POST", "https://dnsapi.cn" + url, strings.NewReader(values.Encode()))
-
-	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
-	req.Header.Set("User-Agent", fmt.Sprintf("GoDNS/0.1 (%s)", configuration.Email))
-
-	response, err := client.Do(req)
-
-	if err != nil {
-		log.Println("Post failed...")
-		log.Println(err)
-		return "", err
-	}
-
-	defer response.Body.Close()
-	resp, _ := ioutil.ReadAll(response.Body)
-
-	return string(resp), nil
-}
--- a/dns_handler_test.go
+++ b/dns_handler_test.go
@ -1,15 +0,0 @@
-package main
-
-import (
-	"testing"
-)
-
-func testGetCurrentIP(t *testing.T) {
-	ip, _ := getCurrentIP("http://members.3322.org/dyndns/getip")
-
-	if ip == "" {
-		t.Log("IP is empty...")
-	} else {
-		t.Log("IP is:" + ip)
-	}
-}
--- a/godns.go
+++ b/godns.go
@ -1,134 +0,0 @@
-package main
-
-import (
-	"flag"
-	"fmt"
-	"log"
-	"os"
-	"runtime/debug"
-	"strings"
-	"time"
-)
-
-const (
-	PANIC_MAX = 5
-	INTERVAL  = 5 //Minute
-)
-
-var (
-	configuration Settings
-	optConf       = flag.String("c", "./config.json", "Specify a config file")
-	optDocker     = flag.Bool("d", false, "Run it as docker mode")
-	optHelp       = flag.Bool("h", false, "Show help")
-	panicCount    = 0
-)
-
-func main() {
-	flag.Parse()
-	if *optHelp {
-		flag.Usage()
-		return
-	}
-
-	if *optDocker {
-		//Load settings from ENV
-		configuration = Settings{
-			Email:      os.Getenv("EMAIL"),
-			Password:   os.Getenv("PASSWORD"),
-			LoginToken: os.Getenv("TOKEN"),
-			IPUrl:      "http://members.3322.org/dyndns/getip",
-			LogPath:    "./godns.log",
-			LogSize:    16,
-			LogNum:     3,
-		}
-
-		if err := LoadDomains(os.Getenv("DOMAINS"), &configuration.Domains); err != nil {
-			fmt.Println(err.Error())
-			log.Println(err.Error())
-			os.Exit(1)
-		}
-	} else {
-		//Load settings from configurations file
-		if err := LoadSettings(*optConf, &configuration); err != nil {
-			fmt.Println(err.Error())
-			log.Println(err.Error())
-			os.Exit(1)
-		}
-	}
-
-	if err := checkSettings(&configuration); err != nil {
-		log.Println("Settings is invalid! ", err.Error())
-		os.Exit(1)
-	}
-
-	if err := InitLogger(configuration.LogPath, configuration.LogSize, configuration.LogNum); err != nil {
-		log.Println("InitLogger error:", err.Error())
-		os.Exit(1)
-	}
-
-	dnsLoop()
-}
-
-func dnsLoop() {
-
-	for _, domain := range configuration.Domains {
-		go DomainLoop(&domain)
-	}
-
-	select {}
-}
-
-func DomainLoop(domain *Domain) {
-	defer func() {
-		if err := recover(); err != nil {
-			panicCount++
-			log.Printf("Recovered in %v: %v\n", err, debug.Stack())
-			fmt.Println(identifyPanic())
-			log.Print(identifyPanic())
-			if panicCount < PANIC_MAX {
-				log.Println("Got panic in goroutine, will start a new one... :", panicCount)
-				go DomainLoop(domain)
-			} else {
-				os.Exit(1)
-			}
-		}
-	}()
-
-	for {
-
-		domainID := getDomain(domain.DomainName)
-
-		if domainID == -1 {
-			continue
-		}
-
-		currentIP, err := getCurrentIP(configuration.IPUrl)
-
-		if err != nil {
-			log.Println("get_currentIP:", err)
-			continue
-		}
-		log.Println("currentIp is:", currentIP)
-
-		for _, subDomain := range domain.SubDomains {
-
-			subDomainID, ip := getSubDomain(domainID, subDomain)
-
-			if subDomainID == "" || ip == "" {
-				log.Printf("domain: %s.%s subDomainID: %s ip: %s\n", subDomain, domain.DomainName, subDomainID, ip)
-				continue
-			}
-
-			//Continue to check the IP of sub-domain
-			if len(ip) > 0 && !strings.Contains(currentIP, ip) {
-				log.Printf("%s.%s Start to update record IP...\n", subDomain, domain.DomainName)
-				updateIP(domainID, subDomainID, subDomain, currentIP)
-			} else {
-				log.Printf("%s.%s Current IP is same as domain IP, no need to update...\n", subDomain, domain.DomainName)
-			}
-		}
-
-		//Interval is 5 minutes
-		time.Sleep(time.Minute * INTERVAL)
-	}
-}
--- a/handler/dnspod_handler.go
+++ b/handler/dnspod_handler.go
@ -0,0 +1,270 @@
+package handler
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"net/url"
+	"runtime/debug"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/TimothyYe/godns"
+	"github.com/bitly/go-simplejson"
+	"golang.org/x/net/proxy"
+)
+
+// DNSPodHandler struct definition
+type DNSPodHandler struct {
+	Configuration *godns.Settings
+}
+
+// SetConfiguration pass dns settings and store it to handler instance
+func (handler *DNSPodHandler) SetConfiguration(conf *godns.Settings) {
+	handler.Configuration = conf
+}
+
+// DomainLoop the main logic loop
+func (handler *DNSPodHandler) 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
+		}
+	}()
+
+	for {
+		log.Printf("Checking IP for domain %s \r\n", domain.DomainName)
+		domainID := handler.GetDomain(domain.DomainName)
+
+		if domainID == -1 {
+			continue
+		}
+
+		currentIP, err := godns.GetCurrentIP(handler.Configuration)
+
+		if err != nil {
+			log.Println("get_currentIP:", err)
+			continue
+		}
+		log.Println("currentIP is:", currentIP)
+
+		for _, subDomain := range domain.SubDomains {
+
+			subDomainID, ip := handler.GetSubDomain(domainID, subDomain)
+
+			if subDomainID == "" || ip == "" {
+				log.Printf("domain: %s.%s subDomainID: %s ip: %s\n", subDomain, domain.DomainName, subDomainID, ip)
+				continue
+			}
+
+			// Continue to check the IP of sub-domain
+			if len(ip) > 0 && strings.TrimRight(currentIP, "\n") != strings.TrimRight(ip, "\n") {
+				log.Printf("%s.%s Start to update record IP...\n", subDomain, domain.DomainName)
+				handler.UpdateIP(domainID, subDomainID, subDomain, currentIP)
+
+				// Send mail notification if notify is enabled
+				if handler.Configuration.Notify.Enabled {
+					log.Print("Sending notification to:", handler.Configuration.Notify.SendTo)
+					godns.SendNotify(handler.Configuration, fmt.Sprintf("%s.%s", subDomain, domain.DomainName), currentIP)
+				}
+
+			} else {
+				log.Printf("%s.%s Current IP is same as domain IP, no need to update...\n", subDomain, domain.DomainName)
+			}
+		}
+
+		// Interval is 5 minutes
+		log.Printf("Going to sleep, will start next checking in %d minutes...\r\n", godns.INTERVAL)
+		time.Sleep(time.Minute * godns.INTERVAL)
+	}
+}
+
+// GenerateHeader generates the request header for DNSPod API
+func (handler *DNSPodHandler) GenerateHeader(content url.Values) url.Values {
+	header := url.Values{}
+	if handler.Configuration.LoginToken != "" {
+		header.Add("login_token", handler.Configuration.LoginToken)
+	} else {
+		header.Add("login_email", handler.Configuration.Email)
+		header.Add("login_password", handler.Configuration.Password)
+	}
+	header.Add("format", "json")
+	header.Add("lang", "en")
+	header.Add("error_on_empty", "no")
+
+	if content != nil {
+		for k := range content {
+			header.Add(k, content.Get(k))
+		}
+	}
+
+	return header
+}
+
+// GetDomain returns specific domain by name
+func (handler *DNSPodHandler) GetDomain(name string) int64 {
+
+	var ret int64
+	values := url.Values{}
+	values.Add("type", "all")
+	values.Add("offset", "0")
+	values.Add("length", "20")
+
+	response, err := handler.PostData("/Domain.List", values)
+
+	if err != nil {
+		log.Println("Failed to get domain list...")
+		return -1
+	}
+
+	sjson, parseErr := simplejson.NewJson([]byte(response))
+
+	if parseErr != nil {
+		log.Println(parseErr)
+		return -1
+	}
+
+	if sjson.Get("status").Get("code").MustString() == "1" {
+		domains, _ := sjson.Get("domains").Array()
+
+		for _, d := range domains {
+			m := d.(map[string]interface{})
+			if m["name"] == name {
+				id := m["id"]
+
+				switch t := id.(type) {
+				case json.Number:
+					ret, _ = t.Int64()
+				}
+
+				break
+			}
+		}
+		if len(domains) == 0 {
+			log.Println("domains slice is empty.")
+		}
+	} else {
+		log.Println("get_domain:status code:", sjson.Get("status").Get("code").MustString())
+	}
+
+	return ret
+}
+
+// GetSubDomain returns subdomain by domain id
+func (handler *DNSPodHandler) GetSubDomain(domainID int64, name string) (string, string) {
+	log.Println("debug:", domainID, name)
+	var ret, ip string
+	value := url.Values{}
+	value.Add("domain_id", strconv.FormatInt(domainID, 10))
+	value.Add("offset", "0")
+	value.Add("length", "1")
+	value.Add("sub_domain", name)
+
+	response, err := handler.PostData("/Record.List", value)
+
+	if err != nil {
+		log.Println("Failed to get domain list")
+		return "", ""
+	}
+
+	sjson, parseErr := simplejson.NewJson([]byte(response))
+
+	if parseErr != nil {
+		log.Println(parseErr)
+		return "", ""
+	}
+
+	if sjson.Get("status").Get("code").MustString() == "1" {
+		records, _ := sjson.Get("records").Array()
+
+		for _, d := range records {
+			m := d.(map[string]interface{})
+			if m["name"] == name {
+				ret = m["id"].(string)
+				ip = m["value"].(string)
+				break
+			}
+		}
+		if len(records) == 0 {
+			log.Println("records slice is empty.")
+		}
+	} else {
+		log.Println("get_subdomain:status code:", sjson.Get("status").Get("code").MustString())
+	}
+
+	return ret, ip
+}
+
+// UpdateIP update subdomain with current IP
+func (handler *DNSPodHandler) UpdateIP(domainID int64, subDomainID string, subDomainName string, ip string) {
+	value := url.Values{}
+	value.Add("domain_id", strconv.FormatInt(domainID, 10))
+	value.Add("record_id", subDomainID)
+	value.Add("sub_domain", subDomainName)
+	value.Add("record_type", "A")
+	value.Add("record_line", "默认")
+	value.Add("value", ip)
+
+	response, err := handler.PostData("/Record.Modify", value)
+
+	if err != nil {
+		log.Println("Failed to update record to new IP!")
+		log.Println(err)
+		return
+	}
+
+	sjson, parseErr := simplejson.NewJson([]byte(response))
+
+	if parseErr != nil {
+		log.Println(parseErr)
+		return
+	}
+
+	if sjson.Get("status").Get("code").MustString() == "1" {
+		log.Println("New IP updated!")
+	}
+
+}
+
+// PostData post data and invoke DNSPod API
+func (handler *DNSPodHandler) PostData(url string, content url.Values) (string, error) {
+	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 {
+			fmt.Println("can't connect to the proxy:", err)
+			return "", err
+		}
+
+		httpTransport := &http.Transport{}
+		client.Transport = httpTransport
+		httpTransport.Dial = dialer.Dial
+	}
+
+	values := handler.GenerateHeader(content)
+	req, _ := http.NewRequest("POST", "https://dnsapi.cn"+url, strings.NewReader(values.Encode()))
+
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req.Header.Set("User-Agent", fmt.Sprintf("GoDNS/0.1 (%s)", handler.Configuration.Email))
+
+	response, err := client.Do(req)
+
+	if err != nil {
+		log.Println("Post failed...")
+		log.Println(err)
+		return "", err
+	}
+
+	defer response.Body.Close()
+	resp, _ := ioutil.ReadAll(response.Body)
+
+	return string(resp), nil
+}
--- a/handler/handler.go
+++ b/handler/handler.go
@ -0,0 +1,23 @@
+package handler
+
+import "github.com/TimothyYe/godns"
+
+// IHandler is the interface for all DNS handlers
+type IHandler interface {
+	SetConfiguration(*godns.Settings)
+	DomainLoop(domain *godns.Domain, panicChan chan<- godns.Domain)
+}
+
+// CreateHandler creates dns handler by different providers
+func CreateHandler(provider string) IHandler {
+	var handler IHandler
+
+	switch provider {
+	case godns.DNSPOD:
+		handler = IHandler(&DNSPodHandler{})
+	case godns.HE:
+		handler = IHandler(&HEHandler{})
+	}
+
+	return handler
+}
--- a/handler/he_handler.go
+++ b/handler/he_handler.go
@ -0,0 +1,104 @@
+package handler
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"net/url"
+	"runtime/debug"
+	"strings"
+	"time"
+
+	"github.com/TimothyYe/godns"
+
+	"golang.org/x/net/proxy"
+)
+
+var (
+	// HEUrl the API address for he.net
+	HEUrl = "https://dyn.dns.he.net/nic/update"
+)
+
+// HEHandler struct
+type HEHandler struct {
+	Configuration *godns.Settings
+}
+
+// SetConfiguration pass dns settings and store it to handler instance
+func (handler *HEHandler) SetConfiguration(conf *godns.Settings) {
+	handler.Configuration = conf
+}
+
+// DomainLoop the main logic loop
+func (handler *HEHandler) 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
+		}
+	}()
+
+	for {
+		currentIP, err := godns.GetCurrentIP(handler.Configuration)
+
+		if err != nil {
+			log.Println("get_currentIP:", err)
+			continue
+		}
+		log.Println("currentIP is:", currentIP)
+
+		for _, subDomain := range domain.SubDomains {
+			log.Printf("%s.%s Start to update record IP...\n", subDomain, domain.DomainName)
+			handler.UpdateIP(domain.DomainName, subDomain, currentIP)
+
+			// Send mail notification if notify is enabled
+			if handler.Configuration.Notify.Enabled {
+				log.Print("Sending notification to:", handler.Configuration.Notify.SendTo)
+				godns.SendNotify(handler.Configuration, fmt.Sprintf("%s.%s", subDomain, domain.DomainName), currentIP)
+			}
+		}
+
+		// Interval is 5 minutes
+		log.Printf("Going to sleep, will start next checking in %d minutes...\r\n", godns.INTERVAL)
+		time.Sleep(time.Minute * godns.INTERVAL)
+	}
+}
+
+// UpdateIP update subdomain with current IP
+func (handler *HEHandler) UpdateIP(domain, subDomain, currentIP string) {
+	values := url.Values{}
+	values.Add("hostname", fmt.Sprintf("%s.%s", subDomain, domain))
+	values.Add("password", handler.Configuration.Password)
+	values.Add("myip", currentIP)
+
+	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
+	}
+
+	req, _ := http.NewRequest("POST", HEUrl, strings.NewReader(values.Encode()))
+	resp, err := client.Do(req)
+
+	if err != nil {
+		log.Println("Request error...")
+		log.Println("Err:", err.Error())
+	} else {
+		body, _ := ioutil.ReadAll(resp.Body)
+		if resp.StatusCode == http.StatusOK {
+			log.Println("Update IP success:", string(body))
+		} else {
+			log.Println("Update IP failed:", string(body))
+		}
+	}
+}
--- a/logger.go
+++ b/logger.go
@ -1,292 +0,0 @@
-package main
-
-import (
-	"bufio"
-	"bytes"
-	"errors"
-	"io"
-	"io/ioutil"
-	"log"
-	"os"
-	"runtime/debug"
-	"strconv"
-	"strings"
-	"sync"
-	"time"
-)
-
-const (
-	L_INFO int = iota
-	L_WARNING
-	L_DEBUG
-	PRE_INFO    = "[   INFO]"
-	PRE_WARNING = "[WARNING]"
-	PRE_DEBUG   = "[  DEBUG]"
-)
-
-type Logger struct {
-	DEV_MODE      bool
-	fd            *os.File
-	size          int
-	num           int
-	level         int
-	mu            sync.Mutex
-	muSplit       sync.Mutex
-	flushInterval int64 //Second
-	flushSize     int
-	buf           *bytes.Buffer
-	log           *log.Logger
-}
-
-func NewLogger(logfile string, size, num int, level int, flushInterval int64, flushSize int) (logger *Logger, err error) {
-	if size < 1 || num < 1 || level < L_INFO || len(logfile) < 1 {
-		err = errors.New("NewLogWriter:param error.")
-		return
-	}
-	logger = &Logger{size: size * 1024, num: num, level: level, DEV_MODE: false}
-	logger.fd, err = os.OpenFile(logfile, os.O_WRONLY|os.O_APPEND|os.O_CREATE, os.ModeAppend|0666)
-	if err != nil {
-		logger = nil
-		return
-	}
-	log.SetOutput(logger)
-	if flushInterval > 0 && flushSize > 0 {
-		logger.buf = new(bytes.Buffer)
-		logger.log = log.New(logger.buf, "", log.LstdFlags)
-
-		go func(interval int64, logger *Logger) {
-			defer func() {
-				if r := recover(); r != nil {
-					log.Printf("logger Tick, Recovered in %v:\n %s", r, debug.Stack())
-				}
-			}()
-			c := time.Tick(time.Duration(interval) * time.Second)
-			for _ = range c {
-				logger.Flush()
-			}
-		}(flushInterval, logger)
-	}
-	return
-}
-
-func InitLogger(logfile string, size, num int) (err error) {
-	logger, err := NewLogger(logfile, size, num, L_INFO, -1, -1)
-	if logger != nil {
-		logger.level = L_INFO - 1
-	}
-	return
-}
-
-//immplement write
-func (this *Logger) Write(p []byte) (n int, err error) {
-	if this.DEV_MODE {
-		n, err = os.Stdout.Write(p)
-		return
-	}
-	n, err = this.fd.Write(p)
-	if err == nil {
-		fi, e := this.fd.Stat()
-		if e != nil {
-			err = e
-			return
-		}
-		if fi.Size() > int64(this.size) {
-			this.muSplit.Lock()
-			defer this.muSplit.Unlock()
-
-			fname := fi.Name()
-			strings.HasSuffix(fname, ".log")
-			fbase := fname[:len(fname)-3]
-
-			oldBs := make([]byte, 0, this.size)
-			newBs := []byte{}
-			fd, e := os.Open(fname)
-			if e != nil {
-				err = e
-				return
-			}
-			rd := bufio.NewReader(fd)
-			for {
-				line, e := rd.ReadBytes('\n')
-				if e == io.EOF {
-					break
-				}
-				if e != nil {
-					err = e
-					return
-				}
-				if len(oldBs)+len(line) > this.size {
-					newBs = append(newBs, line...)
-				} else {
-					oldBs = append(oldBs, line...)
-				}
-			}
-			fd.Close()
-
-			_, err = this.saveLog(1, fbase, oldBs)
-			if err != nil {
-				return
-			}
-			err = this.fd.Close()
-			if err != nil {
-				return
-			}
-			err = os.Remove(fname)
-			if err != nil {
-				return
-			}
-			this.fd, err = os.OpenFile(fname, os.O_WRONLY|os.O_APPEND|os.O_CREATE, os.ModeAppend|0666)
-			if err != nil {
-				return
-			}
-			_, err = this.fd.Write(newBs)
-			if err != nil {
-				return
-			}
-		}
-	}
-	return
-}
-
-func (this *Logger) saveLog(index int, fbase string, data []byte) (n int, err error) {
-	fn := fbase + strconv.Itoa(index) + ".log"
-	_, err = os.Stat(fn)
-	if index < this.num && err == nil {
-		var b []byte
-		b, err = ioutil.ReadFile(fn)
-		if err != nil {
-			return
-		}
-		n, err = this.saveLog(index+1, fbase, b)
-		if err != nil {
-			return
-		}
-	}
-
-	fd, err := os.OpenFile(fn, os.O_WRONLY|os.O_TRUNC|os.O_CREATE, os.ModePerm|0666)
-	if err != nil {
-		return
-	}
-	defer fd.Close()
-	n, err = fd.Write(data)
-	return
-}
-
-//flush buf data to std log
-func (this *Logger) Flush() {
-	if this.buf.Len() > 0 {
-		this.mu.Lock()
-		defer this.mu.Unlock()
-
-		log.SetFlags(0)
-		log.Print(this.buf)
-		log.SetFlags(log.LstdFlags)
-		this.buf.Reset()
-	}
-}
-
-//clean prefix and check buf size
-func (this *Logger) clean() {
-	this.log.SetPrefix("")
-	if this.buf.Len()/1024 > this.flushSize {
-		go this.Flush()
-	}
-}
-
-func (this *Logger) setPrefix(lv int) bool {
-	if lv > this.level {
-		return false
-	}
-
-	switch lv {
-	case L_INFO:
-		this.log.SetPrefix(PRE_INFO)
-	case L_WARNING:
-		this.log.SetPrefix(PRE_WARNING)
-	case L_DEBUG:
-		this.log.SetPrefix(PRE_DEBUG)
-	default:
-		return false
-	}
-	return true
-}
-
-func (this *Logger) logPrint(lv int, args ...interface{}) {
-	this.mu.Lock()
-	defer this.mu.Unlock()
-
-	if !this.setPrefix(lv) {
-		return
-	}
-	this.log.Print(args...)
-	this.clean()
-}
-
-func (this *Logger) logPrintln(lv int, args ...interface{}) {
-	this.mu.Lock()
-	defer this.mu.Unlock()
-
-	if !this.setPrefix(lv) {
-		return
-	}
-	this.log.Println(args...)
-	this.clean()
-}
-
-func (this *Logger) logPrintf(lv int, format string, args ...interface{}) {
-	this.mu.Lock()
-	defer this.mu.Unlock()
-
-	if !this.setPrefix(lv) {
-		return
-	}
-	this.log.Printf(format, args...)
-	this.clean()
-}
-
-//close fd
-func (this *Logger) Close() {
-	if this.fd != nil {
-		this.Flush()
-		this.fd.Close()
-	}
-}
-
-func (this *Logger) Info(args ...interface{}) {
-	this.logPrint(L_INFO, args...)
-}
-
-func (this *Logger) Infoln(args ...interface{}) {
-	this.logPrintln(L_INFO, args...)
-}
-
-func (this *Logger) Infof(format string, args ...interface{}) {
-	this.logPrintf(L_INFO, format, args...)
-}
-
-func (this *Logger) Warning(args ...interface{}) {
-	this.logPrint(L_WARNING, args...)
-}
-
-func (this *Logger) Warningln(args ...interface{}) {
-	this.logPrintln(L_WARNING, args...)
-}
-
-func (this *Logger) Warningf(format string, args ...interface{}) {
-	this.logPrintf(L_WARNING, format, args...)
-}
-
-func (this *Logger) Debug(args ...interface{}) {
-	this.logPrint(L_DEBUG, args...)
-	this.Flush()
-}
-
-func (this *Logger) Debugln(args ...interface{}) {
-	this.logPrintln(L_DEBUG, args...)
-	this.Flush()
-}
-
-func (this *Logger) Debugf(format string, args ...interface{}) {
-	this.logPrintf(L_DEBUG, format, args...)
-	this.Flush()
-}
--- a/settings.go
+++ b/settings.go
@ -1,28 +1,38 @@
-package main
+package godns

 import (
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
-	"strings"
 )

+// Domain struct
 type Domain struct {
 	DomainName string   `json:"domain_name"`
 	SubDomains []string `json:"sub_domains"`
 }

+// Notify struct for SMTP notification
+type Notify struct {
+	Enabled      bool   `json:"enabled"`
+	SMTPServer   string `json:"smtp_server"`
+	SMTPUsername string `json:"smtp_username"`
+	SMTPPassword string `json:"smtp_password"`
+	SMTPPort     int    `json:"smtp_port"`
+	SendTo       string `json:"send_to"`
+}
+
 // Settings struct
 type Settings struct {
+	Provider    string   `json:"provider"`
 	Email       string   `json:"email"`
 	Password    string   `json:"password"`
 	LoginToken  string   `json:"login_token"`
 	Domains     []Domain `json:"domains"`
 	IPUrl       string   `json:"ip_url"`
 	LogPath     string   `json:"log_path"`
-	LogSize    int      `json:"log_size"`
-	LogNum     int      `json:"log_num"`
 	Socks5Proxy string   `json:"socks5_proxy"`
+	Notify      Notify   `json:"notify"`
 }

 // LoadSettings -- Load settings from config file
@ -42,35 +52,3 @@ func LoadSettings(configPath string, settings *Settings) error {

 	return nil
 }
-
-//LoadDomains -- Load domains from domains string
-func LoadDomains(domainsOrginStr string, domains *[]Domain) error {
-
-	domainsMap := make(map[string]*Domain)
-	domainsArray := strings.Split(domainsOrginStr, ",")
-	for _, host := range domainsArray {
-		dotCount := strings.Count(host, ".")
-		if dotCount < 2 {
-			continue
-		}
-		len := len(host)
-		pos := strings.Index(host, ".")
-		subDomain := host[0:pos]
-		domainName := host[pos+1 : len]
-
-		if d, exist := domainsMap[domainName]; exist {
-			d.SubDomains = append(d.SubDomains, subDomain)
-		} else {
-			d := new(Domain)
-			d.DomainName = domainName
-			d.SubDomains = append(d.SubDomains, subDomain)
-			domainsMap[domainName] = d
-		}
-	}
-
-	for _, d := range domainsMap {
-		*domains = append(*domains, *d)
-	}
-
-	return nil
-}
--- a/settings_test.go
+++ b/settings_test.go
@ -1,4 +1,4 @@
-package main
+package godns

 import (
 	"testing"
@ -13,6 +13,11 @@ func TestLoadSetting(t *testing.T) {
 	}

 	if settings.IPUrl == "" {
-		t.Error("Cannot load ip_url from config file")
+		t.Error("cannot load ip_url from config file")
+	}
+
+	err = LoadSettings("./file/does/not/exists", &settings)
+	if err == nil {
+		t.Error("file doesn't exist, should return error")
 	}
 }
--- a/snapshots/he1.png
+++ b/snapshots/he1.png
--- a/snapshots/he2.png
+++ b/snapshots/he2.png
--- a/snapshots/mail.png
+++ b/snapshots/mail.png
--- a/snapshots/notify.png
+++ b/snapshots/notify.png
--- a/template.go
+++ b/template.go
@ -0,0 +1,105 @@
+package godns
+
+var mailTemplate = `
+<html>
+<body>
+    <div role="section">
+        <div style="background-color: #281557;">
+            <div class="layout one-col" style="Margin: 0 auto;max-width: 600px;min-width: 320px; width: 320px;width: calc(28000% - 167400px);overflow-wrap: break-word;word-wrap: break-word;word-break: break-word;">
+                <div class="layout__inner" style="border-collapse: collapse;display: table;width: 100%;">
+                    <!--[if (mso)|(IE)]><table width="100%" cellpadding="0" cellspacing="0" role="presentation"><tr class="layout-full-width" style="background-color: #281557;"><td class="layout__edges">&nbsp;</td><td style="width: 600px" class="w560"><![endif]-->
+                    <div class="column" style="max-width: 600px;min-width: 320px; width: 320px;width: calc(28000% - 167400px);text-align: left;color: #8e959c;font-size: 14px;line-height: 21px;font-family: sans-serif;">
+
+                        <div style="Margin-left: 20px;Margin-right: 20px;">
+                            <div style="mso-line-height-rule: exactly;line-height: 10px;font-size: 1px;">&nbsp;</div>
+                        </div>
+
+                    </div>
+                    <!--[if (mso)|(IE)]></td><td class="layout__edges">&nbsp;</td></tr></table><![endif]-->
+                </div>
+            </div>
+        </div>
+
+        <div style="background-color: #281557;">
+            <div class="layout one-col" style="Margin: 0 auto;max-width: 600px;min-width: 320px; width: 320px;width: calc(28000% - 167400px);overflow-wrap: break-word;word-wrap: break-word;word-break: break-word;">
+                <div class="layout__inner" style="border-collapse: collapse;display: table;width: 100%;">
+                    <!--[if (mso)|(IE)]><table width="100%" cellpadding="0" cellspacing="0" role="presentation"><tr class="layout-full-width" style="background-color: #281557;"><td class="layout__edges">&nbsp;</td><td style="width: 600px" class="w560"><![endif]-->
+                    <div class="column" style="max-width: 600px;min-width: 320px; width: 320px;width: calc(28000% - 167400px);text-align: left;color: #8e959c;font-size: 14px;line-height: 21px;font-family: sans-serif;">
+
+                        <div style="Margin-left: 20px;Margin-right: 20px;">
+                            <div style="mso-line-height-rule: exactly;line-height: 50px;font-size: 1px;">&nbsp;</div>
+                        </div>
+
+                        <div style="Margin-left: 20px;Margin-right: 20px;">
+                            <div style="mso-line-height-rule: exactly;mso-text-raise: 4px;">
+                                <h1 class="size-28" style="Margin-top: 0;Margin-bottom: 0;font-style: normal;font-weight: normal;color: #000;font-size: 24px;line-height: 32px;font-family: avenir,sans-serif;text-align: center;"
+                                    lang="x-size-28">
+                                    <span class="font-avenir">
+                                        <span style="color:#ffffff">Your IP address is changed to</span>
+                                    </span>
+                                </h1>
+                                <h1 class="size-48" style="Margin-top: 20px;Margin-bottom: 0;font-style: normal;font-weight: normal;color: #000;font-size: 36px;line-height: 43px;font-family: avenir,sans-serif;text-align: center;"
+                                    lang="x-size-48">
+                                    <span class="font-avenir">
+                                        <strong>
+                                            <span style="color:#ffffff">{{ .CurrentIP }}</span>
+                                        </strong>
+                                    </span>
+                                </h1>
+                                <h2 class="size-28" style="Margin-top: 20px;Margin-bottom: 16px;font-style: normal;font-weight: normal;color: #e31212;font-size: 24px;line-height: 32px;font-family: Avenir,sans-serif;text-align: center;"
+                                    lang="x-size-28">
+                                    <font color="#ffffff">
+                                        <strong>Domain {{ .Domain }} is updated</strong>
+                                    </font>
+                                </h2>
+                            </div>
+                        </div>
+
+                        <div style="Margin-left: 20px;Margin-right: 20px;">
+                            <div style="mso-line-height-rule: exactly;line-height: 15px;font-size: 1px;">&nbsp;</div>
+                        </div>
+
+                        <div style="Margin-left: 20px;Margin-right: 20px;">
+                            <div style="mso-line-height-rule: exactly;line-height: 35px;font-size: 1px;">&nbsp;</div>
+                        </div>
+
+                    </div>
+                    <!--[if (mso)|(IE)]></td><td class="layout__edges">&nbsp;</td></tr></table><![endif]-->
+                </div>
+            </div>
+        </div>
+
+        <div style="mso-line-height-rule: exactly;line-height: 20px;font-size: 20px;">&nbsp;</div>
+
+
+        <div style="mso-line-height-rule: exactly;" role="contentinfo">
+            <div class="layout email-footer" style="Margin: 0 auto;max-width: 600px;min-width: 320px; width: 320px;width: calc(28000% - 167400px);overflow-wrap: break-word;word-wrap: break-word;word-break: break-word;">
+                <div class="layout__inner" style="border-collapse: collapse;display: table;width: 100%;">
+                    <!--[if (mso)|(IE)]><table align="center" cellpadding="0" cellspacing="0" role="presentation"><tr class="layout-email-footer"><td style="width: 400px;" valign="top" class="w360"><![endif]-->
+                    <div class="column wide" style="text-align: left;font-size: 12px;line-height: 19px;color: #adb3b9;font-family: sans-serif;Float: left;max-width: 400px;min-width: 320px; width: 320px;width: calc(8000% - 47600px);">
+                        <div style="Margin-left: 20px;Margin-right: 20px;Margin-top: 10px;Margin-bottom: 10px;">
+
+                            <div style="font-size: 12px;line-height: 19px;">
+
+                            </div>
+                            <div style="font-size: 12px;line-height: 19px;Margin-top: 18px;">
+
+                            </div>
+                            <!--[if mso]>&nbsp;<![endif]-->
+                        </div>
+                    </div>
+                    <!--[if (mso)|(IE)]></td><td style="width: 200px;" valign="top" class="w160"><![endif]-->
+                    <div class="column narrow" style="text-align: left;font-size: 12px;line-height: 19px;color: #adb3b9;font-family: sans-serif;Float: left;max-width: 320px;min-width: 200px; width: 320px;width: calc(72200px - 12000%);">
+                        <div style="Margin-left: 20px;Margin-right: 20px;Margin-top: 10px;Margin-bottom: 10px;">
+
+                        </div>
+                    </div>
+                    <!--[if (mso)|(IE)]></td></tr></table><![endif]-->
+                </div>
+            </div>
+        </div>
+        <div style="mso-line-height-rule: exactly;line-height: 40px;font-size: 40px;">&nbsp;</div>
+				</body>
+    </div>
+</html>
+`
--- a/utils.go
+++ b/utils.go
@ -1,51 +1,130 @@
-package main
+package godns

 import (
+	"bytes"
 	"errors"
-	"flag"
-	"fmt"
+	"html/template"
+	"io/ioutil"
 	"log"
-	"runtime"
-	"strings"
+	"net/http"
+	"golang.org/x/net/proxy"
+	"gopkg.in/gomail.v2"
 )

-func identifyPanic() string {
-	var name, file string
-	var line int
-	var pc [16]uintptr
+var (
+	// Logo for GoDNS
+	Logo = `

-	n := runtime.Callers(3, pc[:])
-	for _, pc := range pc[:n] {
-		fn := runtime.FuncForPC(pc)
-		if fn == nil {
-			continue
-		}
-		file, line = fn.FileLine(pc)
-		name = fn.Name()
-		if !strings.HasPrefix(name, "runtime.") {
-			break
-		}
+ ██████╗  ██████╗ ██████╗ ███╗   ██╗███████╗
+██╔════╝ ██╔═══██╗██╔══██╗████╗  ██║██╔════╝
+██║  ███╗██║   ██║██║  ██║██╔██╗ ██║███████╗
+██║   ██║██║   ██║██║  ██║██║╚██╗██║╚════██║
+╚██████╔╝╚██████╔╝██████╔╝██║ ╚████║███████║
+ ╚═════╝  ╚═════╝ ╚═════╝ ╚═╝  ╚═══╝╚══════╝
+
+GoDNS V%s
+https://github.com/TimothyYe/godns
+
+`
+)
+
+const (
+	// PanicMax is the max allowed panic times
+	PanicMax = 5
+	// INTERVAL is minute
+	INTERVAL = 5
+	// DNSPOD for dnspod.cn
+	DNSPOD = "DNSPod"
+	// HE for he.net
+	HE = "HE"
+)
+
+// GetCurrentIP gets public IP from internet
+func GetCurrentIP(configuration *Settings) (string, error) {
+	client := &http.Client{}
+
+	if configuration.Socks5Proxy != "" {
+
+		log.Println("use socks5 proxy:" + configuration.Socks5Proxy)
+		dialer, err := proxy.SOCKS5("tcp", configuration.Socks5Proxy, nil, proxy.Direct)
+		if err != nil {
+			log.Println("can't connect to the proxy:", err)
+			return "", err
 		}

-	switch {
-	case name != "":
-		return fmt.Sprintf("%v:%v", name, line)
-	case file != "":
-		return fmt.Sprintf("%v:%v", file, line)
+		httpTransport := &http.Transport{}
+		client.Transport = httpTransport
+		httpTransport.Dial = dialer.Dial
 	}

-	return fmt.Sprintf("pc:%x", pc)
+	response, err := client.Get(configuration.IPUrl)
+
+	if err != nil {
+		log.Println("Cannot get IP...")
+		return "", err
 	}

-func usage() {
-	log.Println("[command] -c=[config file path]")
-	flag.PrintDefaults()
+	defer response.Body.Close()
+
+	body, _ := ioutil.ReadAll(response.Body)
+	return string(body), nil
 }

-func checkSettings(config *Settings) error {
+// CheckSettings check the format of settings
+func CheckSettings(config *Settings) error {
+	if config.Provider == DNSPOD {
 		if (config.Email == "" || config.Password == "") && config.LoginToken == "" {
-		return errors.New("Input email/password or login token cannot be empty!")
+			return errors.New("email/password or login token cannot be empty")
+		}
+	} else if config.Provider == HE {
+		if config.Password == "" {
+			return errors.New("password cannot be empty")
+		}
+	} else {
+		return errors.New("please provide supported DNS provider: DNSPod/HE")
 	}

 	return nil
 }
+
+// SendNotify sends mail notify if IP is changed
+func SendNotify(configuration *Settings, domain, currentIP string) error {
+	m := gomail.NewMessage()
+
+	m.SetHeader("From", configuration.Notify.SMTPUsername)
+	m.SetHeader("To", configuration.Notify.SendTo)
+	m.SetHeader("Subject", "GoDNS Notification")
+	log.Println("currentIP:", currentIP)
+	log.Println("domain:", domain)
+	m.SetBody("text/html", buildTemplate(currentIP, domain))
+
+	d := gomail.NewPlainDialer(configuration.Notify.SMTPServer, configuration.Notify.SMTPPort, configuration.Notify.SMTPUsername, configuration.Notify.SMTPPassword)
+
+	// Send the email config by sendlist	.
+	if err := d.DialAndSend(m); err != nil {
+		log.Println("Send email notification with error:", err.Error())
+		return err
+	}
+	return nil
+}
+
+func buildTemplate(currentIP, domain string) string {
+	t := template.New("notification template")
+	t.Parse(mailTemplate)
+
+	data := struct {
+		CurrentIP string
+		Domain    string
+	}{
+		currentIP,
+		domain,
+	}
+
+	var tpl bytes.Buffer
+	if err := t.Execute(&tpl, data); err != nil {
+		log.Println(err.Error())
+		return ""
+	}
+
+	return tpl.String()
+}
--- a/utils_test.go
+++ b/utils_test.go
@ -0,0 +1,49 @@
+package godns
+
+import (
+	"testing"
+)
+
+func TestGetCurrentIP(t *testing.T) {
+	conf := &Settings{IPUrl: "http://members.3322.org/dyndns/getip"}
+	ip, _ := GetCurrentIP(conf)
+
+	if ip == "" {
+		t.Log("IP is empty...")
+	} else {
+		t.Log("IP is:" + ip)
+	}
+
+	conf = &Settings{Socks5Proxy: "localhost:8899", IPUrl: "http://members.3322.org/dyndns/getip"}
+	ip, err := GetCurrentIP(conf)
+
+	if ip != "" && err == nil {
+		t.Error("should return error")
+	}
+}
+
+func TestCheckSettings(t *testing.T) {
+	settingError := &Settings{}
+	if err := CheckSettings(settingError); err == nil {
+		t.Error("setting is invalid, should return error")
+	}
+
+	settingDNSPod := &Settings{Provider: "DNSPod", LoginToken: "aaa"}
+	if err := CheckSettings(settingDNSPod); err == nil {
+		t.Log("setting with login token, passed")
+	} else {
+		t.Error("setting with login token, should be passed")
+	}
+
+	settingDNSPod = &Settings{Provider: "DNSPod"}
+	if err := CheckSettings(settingDNSPod); err == nil {
+		t.Error("setting with invalid parameters, should be failed")
+	}
+
+	settingHE := &Settings{Provider: "HE", Password: ""}
+	if err := CheckSettings(settingHE); err != nil {
+		t.Log("HE setting without password, passed")
+	} else {
+		t.Error("HE setting without password, should be faild")
+	}
+}