force shutdown upon receiving second os signal

Signed-off-by: sami <sami@appscode.com>

Author: samiulsami

internal/listener/listener.go

@@ -11,6 +11,7 @@ import (
 	"strconv"
 	"sync"
 	"sync/atomic"
+	"syscall"
 	"time"
 
 	"kubeops.dev/pgoutbox/apis"
@@ -138,6 +139,16 @@ func (l *Listener) InitHandlers(ctx context.Context) {
 	shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancel()
 
+	// ref: https://github.com/appscode-cloud/cloud-be/blob/79fd250eeb79d47abdd2d38525a0b9b21e1920cf/common/util/signal.go
+	shutdownHandler := make(chan os.Signal, 2)
+	signal.Notify(shutdownHandler, os.Interrupt, syscall.SIGTERM)
+	go func() {
+		<-shutdownHandler
+		cancel()
+		<-shutdownHandler
+		os.Exit(1) // force exit upon receiving second signal
+	}()
+
 	if err := srv.Shutdown(shutdownCtx); err != nil {
 		l.log.Error("http server shutdown error", "err", err)
 	}