fix: Make sure that we can't connect after we stop the bindings liste…

…ner (#469)

pkg/bindingsdriver/driver.go

@@ -59,9 +59,11 @@ type ConnectionHandler func(net.Conn) error
 
 type bindingsListener struct {
 	listener    net.Listener
-	stop        chan struct{}
 	cnxnHandler ConnectionHandler
 	log         logr.Logger
+
+	stopOnce sync.Once
+	stop     chan struct{}
 }
 
 func newBindingsListener(address string, cnxnHandler ConnectionHandler) (*bindingsListener, error) {
@@ -72,8 +74,8 @@ func newBindingsListener(address string, cnxnHandler ConnectionHandler) (*bindin
 
 	bl := &bindingsListener{
 		listener:    l,
-		stop:        make(chan struct{}),
 		cnxnHandler: cnxnHandler,
+		stop:        make(chan struct{}),
 	}
 
 	go bl.run()
@@ -83,18 +85,16 @@ func newBindingsListener(address string, cnxnHandler ConnectionHandler) (*bindin
 
 // Stop stops the listener. It is safe to call stop multiple times.
 func (b *bindingsListener) Stop() {
-	select {
-	case b.stop <- struct{}{}:
-		close(b.stop)
-	default:
-	}
+	b.stopOnce.Do(func() {
+		b.listener.Close()
+		b.stop <- struct{}{}
+	})
 }
 
 func (b *bindingsListener) run() {
 	for {
 		select {
 		case <-b.stop:
-			b.listener.Close()
 			return
 		default:
 		}

pkg/bindingsdriver/driver_test.go

@@ -6,6 +6,7 @@ import (
 	"math/rand/v2"
 	"net"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 )
@@ -35,7 +36,7 @@ func TestBindingsListener(t *testing.T) {
 	assert.NotNil(t, bl)
 
 	// test that we can connect to the listener
-	conn, err := net.Dial("tcp", loopbackAddr(port))
+	conn, err := net.DialTimeout("tcp", loopbackAddr(port), 10*time.Millisecond)
 	assert.NoError(t, err)
 
 	out, err := io.ReadAll(conn)
@@ -44,6 +45,13 @@ func TestBindingsListener(t *testing.T) {
 	assert.Equal(t, "hello world", string(out))
 
 	assert.NotPanics(t, func() { bl.Stop() })
+
+	// test that we can't connect to the listener after it's stopped
+	conn, err = net.DialTimeout("tcp", loopbackAddr(port), 10*time.Millisecond)
+	assert.Error(t, err)
+	assert.Nil(t, conn)
+
+	// test that we can stop the listener multiple times
 	assert.NotPanics(t, func() { bl.Stop() })
 }