test(kuberuntime): deflake TestRecordOperation

Avoid using hard-coded port

Signed-off-by: knight42 <[email protected]>

Author: knight42

pkg/kubelet/kuberuntime/instrumented_services_test.go

@@ -34,17 +34,16 @@ func TestRecordOperation(t *testing.T) {
 	legacyregistry.MustRegister(metrics.RuntimeOperationsDuration)
 	legacyregistry.MustRegister(metrics.RuntimeOperationsErrors)
 
-	temporalServer := "127.0.0.1:1234"
-	l, err := net.Listen("tcp", temporalServer)
+	l, err := net.Listen("tcp", "127.0.0.1:0")
 	assert.NoError(t, err)
 	defer l.Close()
 
-	prometheusURL := "http://" + temporalServer + "/metrics"
+	prometheusURL := "http://" + l.Addr().String() + "/metrics"
 	mux := http.NewServeMux()
 	//lint:ignore SA1019 ignore deprecated warning until we move off of global registries
 	mux.Handle("/metrics", legacyregistry.Handler())
 	server := &http.Server{
-		Addr:    temporalServer,
+		Addr:    l.Addr().String(),
 		Handler: mux,
 	}
 	go func() {