pyk / session

modular & configurable SMTP server. work well with net libs package

Session

modular & testable SMTP server written in Go. work well with net libs package.

example of usage :

// SMTP server
// gracefully shutdown
package main

import (
    "log"
    "net"
    "os"
    "os/signal"
    "sync"
    "syscall"
    "time"

    "github.com/pyk/session"
)

type SMTPserver struct {
    Listener *net.TCPListener
    Stoped   chan bool
    Wg       *sync.WaitGroup
}

func (smtps *SMTPserver) Run() {
    defer smtps.Wg.Done()
    for {
        select {
        case <-smtps.Stoped:
            log.Println("smtpserver: stopping listening on", smtps.Listener.Addr())
            smtps.Listener.Close()
            return
        default:
        }

        // make sure listener.AcceptTCP() doesn't block forever
        // so it can read a stopped channel
        smtps.Listener.SetDeadline(time.Now().Add(1e9))
        conn, err := smtps.Listener.AcceptTCP()
        if err != nil {
            if opErr, ok := err.(*net.OpError); ok && opErr.Timeout() {
                continue
            }
            log.Println(err)
        }

        smtps.Wg.Add(1)
        s := session.New(conn, smtps.Wg, smtps.Stoped)
        go s.Serve()
    }
}

func (smtps *SMTPserver) Stop() {
    close(smtps.Stoped)
    smtps.Wg.Wait()
}

func main() {

    tcpAddr, err := net.ResolveTCPAddr("tcp4", ":8080")
    if err != nil {
        log.Fatal(err)
    }

    listener, err := net.ListenTCP("tcp", tcpAddr)
    if err != nil {
        log.Fatal(err)
    }

    log.Printf("smtpserver: listening on %s", listener.Addr())

    server := &SMTPserver{
        Listener: listener,
        Stoped:   make(chan bool),
        Wg:       &sync.WaitGroup{},
    }

    server.Wg.Add(1)
    go server.Run()

    chs := make(chan os.Signal)
    signal.Notify(chs, syscall.SIGINT, syscall.SIGTERM)
    log.Println(<-chs)

    server.Stop()
}