dnsupdater/main.go

package main

import (
	"encoding/json"
	"fmt"
	"gopkg.in/src-d/go-git.v4"
	"gopkg.in/src-d/go-git.v4/plumbing/object"
	githttp "gopkg.in/src-d/go-git.v4/plumbing/transport/http"
	"io/ioutil"
	"net/http"
	"os"
	"path"
	"regexp"
	"strings"
	"time"
)

type Configuration struct {
	RepositoryUrl string `json:"url"`
	Username string `json:"name"`
	Email string `json:"email"`
	GitLogin string `json:"login"`
	GitPassword string `json:"password"`
}

var configPath string

func main() {

	Info("Running dnsupdater...")

	configPath = os.Args[1]

	if confPathExists, _ := exists(configPath); !confPathExists{
		configPath = "./data";
	}

	file, _ := os.Open(path.Join(configPath,"conf.json"))
	defer file.Close()
	decoder := json.NewDecoder(file)
	configuration := Configuration{}
	err := decoder.Decode(&configuration)

	err = os.RemoveAll(path.Join(configPath,"data"))
	CheckIfError(err)

	_, err = git.PlainClone(path.Join(configPath,"data"), false, &git.CloneOptions{
		URL:      configuration.RepositoryUrl,
		Progress: os.Stdout,
	})
	CheckIfError(err)

	currentIp := GetCurrentIp()
	newIp := GetOutboundIP()

	if currentIp == newIp {
		Info("Ip has not changed %s", currentIp)
		os.Exit(0)
	}

	Info("Ip has changed %s -> %s", currentIp, newIp)
	SetCurrentIp(currentIp, newIp)

	repo, err := git.PlainOpen(path.Join(configPath,"data"))
	CheckIfError(err)
	w, err := repo.Worktree()
	CheckIfError(err)
	_, err = w.Add("templates/home_a.lua")
	CheckIfError(err)

	status, err := w.Status()
	CheckIfError(err)

	fmt.Println(status)
	_, err = w.Commit(fmt.Sprintf("Changement d'IP maison : %s -> %s", currentIp, newIp), &git.CommitOptions{
		Author: &object.Signature{
			Name:  configuration.Username,
			Email: configuration.Email,
			When:  time.Now().Local(),
		},
	})
	CheckIfError(err)

	err = repo.Push(&git.PushOptions{
		Auth: &githttp.BasicAuth{
			Username: configuration.GitLogin,
			Password: configuration.GitPassword,
		},
	})
	CheckIfError(err)

}

func GetCurrentIp() string {
	b, err := ioutil.ReadFile(path.Join(configPath,"data/templates/home_a.lua"))
	CheckIfError(err)

	re := regexp.MustCompile("\"(.*?)\"")
	match := re.FindStringSubmatch(string(b))
	return match[1]
}

func SetCurrentIp(oldip string, newip string) {
	b, err := ioutil.ReadFile(path.Join(configPath,"data/templates/home_a.lua"))
	CheckIfError(err)

	s := string(b)
	s = strings.Replace(s, oldip, newip, 1)
	ioutil.WriteFile(path.Join(configPath,"data/templates/home_a.lua"), []byte(s), 0644)
}

func CheckIfError(err error) {
	if err == nil {
		return
	}

	fmt.Printf("\x1b[31;1m%s\x1b[0m\n", fmt.Sprintf("error: %s", err))
	os.Exit(1)
}

func GetOutboundIP() string {
	url := "https://diagnostic.opendns.com/myip"
	req, err := http.NewRequest("GET", url, nil)
	CheckIfError(err)
	res, err := http.DefaultClient.Do(req)
	CheckIfError(err)
	defer res.Body.Close()
	body, err := ioutil.ReadAll(res.Body)
	CheckIfError(err)
	return string(body)
}

func exists(path string) (bool, error) {
	_, err := os.Stat(path)
	if err == nil {
		return true, nil
	}
	if os.IsNotExist(err) {
		return false, nil
	}
	return true, err
}

func Info(format string, args ...interface{}) {
	fmt.Printf("\x1b[34;1m%s\x1b[0m\n", fmt.Sprintf(format, args...))
}