e2e test use websockets as default for exec operations

Author: aojea

test/e2e/framework/pod/exec_util.go

@@ -27,6 +27,7 @@ import (
 
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/httpstream"
 	"k8s.io/client-go/kubernetes/scheme"
 	restclient "k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/remotecommand"
@@ -80,8 +81,8 @@ func ExecWithOptionsContext(ctx context.Context, f *framework.Framework, options
 	}, scheme.ParameterCodec)
 
 	var stdout, stderr bytes.Buffer
-	framework.Logf("ExecWithOptions: execute(POST %s)", req.URL())
-	err := execute(ctx, "POST", req.URL(), f.ClientConfig(), options.Stdin, &stdout, &stderr, tty)
+	framework.Logf("ExecWithOptions: execute(%s)", req.URL())
+	err := execute(ctx, req.URL(), f.ClientConfig(), options.Stdin, &stdout, &stderr, tty)
 
 	if options.PreserveWhitespace {
 		return stdout.String(), stderr.String(), err
@@ -181,11 +182,29 @@ func VerifyExecInPodFail(ctx context.Context, f *framework.Framework, pod *v1.Po
 	return fmt.Errorf("%q should fail with exit code %d, but exit without error", shExec, exitCode)
 }
 
-func execute(ctx context.Context, method string, url *url.URL, config *restclient.Config, stdin io.Reader, stdout, stderr io.Writer, tty bool) error {
-	exec, err := remotecommand.NewSPDYExecutor(config, method, url)
+func execute(ctx context.Context, url *url.URL, config *restclient.Config, stdin io.Reader, stdout, stderr io.Writer, tty bool) error {
+	// WebSocketExecutor executor is default
+	// WebSocketExecutor must be "GET" method as described in RFC 6455 Sec. 4.1 (page 17).
+	websocketExec, err := remotecommand.NewWebSocketExecutor(config, "GET", url.String())
 	if err != nil {
 		return err
 	}
+	spdyExec, err := remotecommand.NewSPDYExecutor(config, "POST", url)
+	if err != nil {
+		return err
+	}
+	exec, err := remotecommand.NewFallbackExecutor(websocketExec, spdyExec, func(err error) bool {
+		if httpstream.IsUpgradeFailure(err) || httpstream.IsHTTPSProxyError(err) {
+			framework.Logf("fallback to secondary dialer from primary dialer err: %v", err)
+			return true
+		}
+		framework.Logf("unexpected error trying to use websockets for pod exec: %v", err)
+		return false
+	})
+	if err != nil {
+		return err
+	}
+
 	return exec.StreamWithContext(ctx, remotecommand.StreamOptions{
 		Stdin:  stdin,
 		Stdout: stdout,