emailer/main.go

package main

import (
	"encoding/json"
	"flag"
	"fmt"
	"io/ioutil"
	"net/http"
	"os"
	"time"

	"github.com/rs/zerolog"
	"github.com/rs/zerolog/log"
	"gopkg.in/gomail.v2"
	"kumoly.io/kumoly/app/email"
	"kumoly.io/lib/guard"
)

var (
	fName        string
	fLink        string
	fLogo        string
	fTroubleText string

	fHost string
	fPort int
	fUsr  string
	fPwd  string

	flagAddr string
	fSAllow  string

	flagLogLevel  int
	flagLogPretty bool

	Version string = "v0.0.0"
	Build   string = "alpha"
)

func init() {
	flag.StringVar(&fName, "name", "", "name of the app")
	flag.StringVar(&fLink, "link", "", "link url of the app")
	flag.StringVar(&fLogo, "logo", "", "logo url of the app")
	flag.StringVar(&fTroubleText, "no-link-text", "", "TroubleText of the app")

	flag.StringVar(&fHost, "s-host", "mail.kumoly.io", "SMTP host")
	flag.IntVar(&fPort, "s-port", 587, "SMTP port")
	flag.StringVar(&fUsr, "s-user", "test@kumoly.io", "SMTP user")
	flag.StringVar(&fPwd, "s-passwd", "test", "SMTP password")

	flag.StringVar(&flagAddr, "addr", ":8000", "address to listen")
	flag.StringVar(&fSAllow, "allow", "", "allowed ipnet")

	flag.IntVar(&flagLogLevel, "level", 1, "log level [-1(trace):5(panic)] 7 to disable")
	flag.BoolVar(&flagLogPretty, "pretty", false, "log message in human readable format (the original log is json)")
}

func main() {
	flag.Parse()

	zerolog.TimeFieldFormat = zerolog.TimeFormatUnix
	zerolog.SetGlobalLevel(zerolog.Level(flagLogLevel))
	if flagLogPretty {
		log.Logger = log.Output(zerolog.ConsoleWriter{
			Out:        os.Stdout,
			TimeFormat: "2006/01/02 15:04:05",
		})
	}

	email.SetDefault(email.App{
		Name: fName,
		Link: fLink,
		Logo: fLogo,
		Copyright: fmt.Sprintf("Copyright © %v %s. All rights reserved.",
			time.Now().Year(), fName),
		TroubleText: fTroubleText,
		Theme:       "#F2F4F6",
		TitleColor:  "#2F3133",
		FooterColor: "#AEAEAE",
	})
	email.SetDailer(gomail.NewDialer(fHost, fPort, fUsr, fPwd))

	mux := http.NewServeMux()
	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPost {
			http.NotFound(w, r)
			return
		}
		data, err := ioutil.ReadAll(r.Body)
		r.Body.Close()
		if err != nil {
			panic(err)
		}
		var e Email
		if err := json.Unmarshal(data, &e); err != nil {
			panic(err)
		}
		if err := email.Send(e.From, e.To, e.Title, &e.Body); err != nil {
			panic(err)
		}
		w.Write([]byte("ok"))
	})

	g := guard.New()
	g.Skip = guard.SkipStatic

	server := &http.Server{
		Addr:    flagAddr,
		Handler: g.Guard(mux),
	}

	log.Info().Msgf("%s started at %s", fName, flagAddr)
	err := server.ListenAndServe()
	if err != nil {
		log.Error().Err(err)
	}
}

type Email struct {
	From  string
	To    []string
	Title string
	Body  email.Body
}