feat: use websockets for port forwards (#3717)

Signed-off-by: Austin Abro <[email protected]>

Author: AustinAbro321

src/pkg/cluster/tunnel.go

@@ -16,6 +16,7 @@ import (
 
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/httpstream"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/portforward"
@@ -456,12 +457,10 @@ func (tunnel *Tunnel) establish(ctx context.Context) (string, error) {
 
 	l.Debug("using URL to create portforward", "url", portForwardCreateURL)
 
-	// Construct the spdy client required by the client-go portforward library.
-	transport, upgrader, err := spdy.RoundTripperFor(tunnel.restConfig)
+	dialer, err := createDialer("POST", portForwardCreateURL, tunnel.restConfig)
 	if err != nil {
-		return "", fmt.Errorf("unable to create the spdy client %w", err)
+		return "", fmt.Errorf("unable to create the dialer %w", err)
 	}
-	dialer := spdy.NewDialer(upgrader, &http.Client{Transport: transport}, "POST", portForwardCreateURL)
 
 	// Construct a new PortForwarder struct that manages the instructed port forward tunnel.
 	ports := []string{fmt.Sprintf("%d:%d", localPort, tunnel.remotePort)}
@@ -530,3 +529,21 @@ func (tunnel *Tunnel) getAttachablePodForService(ctx context.Context) (string, e
 	}
 	return podList.Items[0].Name, nil
 }
+
+// Inspired by https://github.com/kubernetes/kubernetes/blob/680ea07dbb2c6050d13b93660fa4d27d2d28d6eb/staging/src/k8s.io/kubectl/pkg/cmd/portforward/portforward.go#L139-L156
+func createDialer(method string, url *url.URL, config *rest.Config) (httpstream.Dialer, error) {
+	transport, upgrader, err := spdy.RoundTripperFor(config)
+	if err != nil {
+		return nil, err
+	}
+	dialer := spdy.NewDialer(upgrader, &http.Client{Transport: transport}, method, url)
+	tunnelingDialer, err := portforward.NewSPDYOverWebsocketDialer(url, config)
+	if err != nil {
+		return nil, err
+	}
+	// First attempt tunneling (websocket) dialer, then fallback to spdy dialer.
+	dialer = portforward.NewFallbackDialer(tunnelingDialer, dialer, func(err error) bool {
+		return httpstream.IsUpgradeFailure(err) || httpstream.IsHTTPSProxyError(err)
+	})
+	return dialer, nil
+}