if runtime.GOOS != "linux" {
		t.Skip()
	}

	l, err := net.Listen("tcp", "localhost:0") // ask kernel for a free port.
	if err != nil {
		t.Fatal(err)
	}
	defer l.Close()

	port := l.Addr().(*net.TCPAddr).Port

	testCases := []struct {
		host        string
		port        int
		expectedErr error
	}{
		{"", port, fmt.Errorf("listen tcp :%v: bind: address already in use", port)},

// Note: The check method tries to listen on given port and closes it.
// It is possible to have a disconnected client in this tiny window of time.
func CheckPortAvailability(host, port string, opts TCPOptions) (err error) {
	lc := &net.ListenConfig{}

	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()

	l, err := lc.Listen(ctx, "tcp", net.JoinHostPort(host, port))
	if err != nil {

    upstream minio {
        server site1-minio1:9000;
        server site1-minio2:9000;
        server site1-minio3:9000;
        server site1-minio4:9000;
    }

    server {
        listen       9001;
        listen  [::]:9001;
        server_name  localhost;

        # To allow special characters in headers
        ignore_invalid_headers off;
        # Allow any size file to be uploaded.

    upstream minio {
        server site2-minio1:9000;
        server site2-minio2:9000;
        server site2-minio3:9000;
        server site2-minio4:9000;
    }

    server {
        listen       9002;
        listen  [::]:9002;
        server_name  localhost;

        # To allow special characters in headers
        ignore_invalid_headers off;
        # Allow any size file to be uploaded.

    upstream minio {
        server minio1:9000;
        server minio2:9000;
        server minio3:9000;
        server minio4:9000;
    }

    # main minio
    server {
        listen       9000;
        listen  [::]:9000;
        server_name  localhost;

         # To allow special characters in headers
         ignore_invalid_headers off;
         # Allow any size file to be uploaded.

)

func SetupMonitoring(port int, path string, stop <-chan struct{}) {
	if port <= 0 {
		return
	}
	mux := http.NewServeMux()
	var listener net.Listener
	var err error
	if listener, err = net.Listen("tcp", fmt.Sprintf(":%d", port)); err != nil {
		log.Errorf("unable to listen on socket: %v", err)
		return
	}
	exporter, err := monitoring.RegisterPrometheusExporter(nil, nil)
	if err != nil {

				panic(err)
			}
		}
	}
}

func getHosts(n int) (hosts []string, listeners []net.Listener, err error) {
	for i := 0; i < n; i++ {
		l, err := net.Listen("tcp", "127.0.0.1:0")
		if err != nil {
			if l, err = net.Listen("tcp6", "[::1]:0"); err != nil {
				return nil, nil, fmt.Errorf("httptest: failed to listen on a port: %v", err)
			}
		}
		addr := l.Addr()
		hosts = append(hosts, "http://"+addr.String())

 * shared resources.
 *
 * @param <K> the most general type of keys this listener can listen for; for example {@code Object}
 *     if any key is acceptable
 * @param <V> the most general type of values this listener can listen for; for example {@code
 *     Object} if any key is acceptable
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible

 * shared resources.
 *
 * @param <K> the most general type of keys this listener can listen for; for example {@code Object}
 *     if any key is acceptable
 * @param <V> the most general type of values this listener can listen for; for example {@code
 *     Object} if any key is acceptable
 * @author Charles Fry
 * @since 10.0
 */
@GwtCompatible
@FunctionalInterface

  --name etcd-gcr-v3.3.9 \
  gcr.io/etcd-development/etcd:v3.3.9 \
  /usr/local/bin/etcd \
  --name s1 \
  --data-dir /etcd-data \
  --listen-client-urls http://0.0.0.0:2379 \
  --advertise-client-urls http://0.0.0.0:2379 \
  --listen-peer-urls http://0.0.0.0:2380 \
  --initial-advertise-peer-urls http://0.0.0.0:2380 \
  --initial-cluster s1=http://0.0.0.0:2380 \
  --initial-cluster-token tkn \