smtp2shoutrrr/main.go
2024-11-21 22:27:30 +01:00

140 lines
3.2 KiB
Go

package main
import (
"context"
"errors"
"io"
"log"
"log/slog"
"net/http"
"time"
"git.nakama.town/fmartingr/gotoolkit/model"
"git.nakama.town/fmartingr/gotoolkit/service"
"github.com/emersion/go-sasl"
"github.com/emersion/go-smtp"
)
var _ model.Server = (*smtpServer)(nil)
type smtpServer struct {
backend *smtp.Server
}
func (s *smtpServer) IsEnabled() bool {
return true
}
func (s *smtpServer) Start(_ context.Context) error {
slog.Info("Started SMTP server", slog.String("addr", s.backend.Addr))
return s.backend.ListenAndServe()
}
func (s *smtpServer) Stop(ctx context.Context) error {
slog.Info("Stopping SMTP server")
return s.backend.Shutdown(ctx)
}
func NewSMTPServer(backend *smtp.Server) model.Server {
return &smtpServer{
backend: backend,
}
}
// The Backend implements SMTP server methods.
type Backend struct{}
// NewSession is called after client greeting (EHLO, HELO).
func (bkd *Backend) NewSession(c *smtp.Conn) (smtp.Session, error) {
return &Session{}, nil
}
// A Session is returned after successful login.
type Session struct{}
// AuthMechanisms returns a slice of available auth mechanisms; only PLAIN is
// supported in this example.
func (s *Session) AuthMechanisms() []string {
return []string{sasl.Plain}
}
// Auth is the handler for supported authenticators.
func (s *Session) Auth(mech string) (sasl.Server, error) {
return sasl.NewPlainServer(func(identity, username, password string) error {
if username != "username" || password != "password" {
return errors.New("Invalid username or password")
}
return nil
}), nil
}
func (s *Session) Mail(from string, opts *smtp.MailOptions) error {
log.Println("Mail from:", from, opts)
return nil
}
func (s *Session) Rcpt(to string, opts *smtp.RcptOptions) error {
log.Println("Rcpt to:", to)
return nil
}
func (s *Session) Data(r io.Reader) error {
_, err := http.Post("https://ntfy.sh/fmartingr-dev", "text/plain", r)
if err != nil {
slog.Error("Error sending message:", slog.String("err", err.Error()))
}
return nil
}
func (s *Session) Reset() {}
func (s *Session) Logout() error {
return nil
}
// ExampleServer runs an example SMTP server.
//
// It can be tested manually with e.g. netcat:
//
// > netcat -C localhost 1025
// EHLO localhost
// AUTH PLAIN
// AHVzZXJuYW1lAHBhc3N3b3Jk
// MAIL FROM:<root@nsa.gov>
// RCPT TO:<root@gchq.gov.uk>
// DATA
// Hey <3
// .
func main() {
be := &Backend{}
smtpBackend := smtp.NewServer(be)
smtpBackend.Addr = "localhost:11025"
smtpBackend.Domain = "localhost"
smtpBackend.WriteTimeout = 10 * time.Second
smtpBackend.ReadTimeout = 10 * time.Second
smtpBackend.MaxMessageBytes = 1024 * 1024
smtpBackend.MaxRecipients = 50
smtpBackend.AllowInsecureAuth = true
ctx := context.Background()
smtpServer := NewSMTPServer(smtpBackend)
svc, err := service.NewService([]model.Server{
smtpServer,
})
if err != nil {
slog.Error("Error creating service:", slog.String("err", err.Error()))
return
}
if err := svc.Start(ctx); err != nil {
slog.Error("Error starting service:", slog.String("err", err.Error()))
return
}
if err := svc.WaitStop(ctx); err != nil {
slog.Error("Error waiting for service interruption:", slog.String("err", err.Error()))
}
}