remote command turn on feature gates

Kubernetes-commit: a147693deb2e7f040cf367aae4a7ae5d1cb3e7aa

pkg/cmd/attach/attach.go

@@ -158,23 +158,10 @@ type DefaultRemoteAttach struct{}
 
 // Attach executes attach to a running container
 func (*DefaultRemoteAttach) Attach(url *url.URL, config *restclient.Config, stdin io.Reader, stdout, stderr io.Writer, tty bool, terminalSizeQueue remotecommand.TerminalSizeQueue) error {
-	// Legacy SPDY executor is default. If feature gate enabled, fallback
+	exec, err := createExecutor(url, config)
-	// executor attempts websockets first--then SPDY.
-	exec, err := remotecommand.NewSPDYExecutor(config, "POST", url)
 	if err != nil {
 		return err
 	}
-	if cmdutil.RemoteCommandWebsockets.IsEnabled() {
-		// 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
-		}
-		exec, err = remotecommand.NewFallbackExecutor(websocketExec, exec, httpstream.IsUpgradeFailure)
-		if err != nil {
-			return err
-		}
-	}
 	return exec.StreamWithContext(context.Background(), remotecommand.StreamOptions{
 		Stdin:             stdin,
 		Stdout:            stdout,
@@ -184,6 +171,27 @@ func (*DefaultRemoteAttach) Attach(url *url.URL, config *restclient.Config, stdi
 	})
 }
 
+// createExecutor returns the Executor or an error if one occurred.
+func createExecutor(url *url.URL, config *restclient.Config) (remotecommand.Executor, error) {
+	exec, err := remotecommand.NewSPDYExecutor(config, "POST", url)
+	if err != nil {
+		return nil, err
+	}
+	// Fallback executor is default, unless feature flag is explicitly disabled.
+	if !cmdutil.RemoteCommandWebsockets.IsDisabled() {
+		// 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 nil, err
+		}
+		exec, err = remotecommand.NewFallbackExecutor(websocketExec, exec, httpstream.IsUpgradeFailure)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return exec, nil
+}
+
 // Complete verifies command line arguments and loads data from the command environment
 func (o *AttachOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []string) error {
 	var err error

pkg/cmd/attach/attach_test.go

@@ -37,6 +37,7 @@ import (
 	"k8s.io/client-go/tools/remotecommand"
 	"k8s.io/kubectl/pkg/cmd/exec"
 	cmdtesting "k8s.io/kubectl/pkg/cmd/testing"
+	cmdutil "k8s.io/kubectl/pkg/cmd/util"
 	"k8s.io/kubectl/pkg/cmd/util/podcmd"
 	"k8s.io/kubectl/pkg/polymorphichelpers"
 	"k8s.io/kubectl/pkg/scheme"
@@ -553,3 +554,37 @@ func TestReattachMessage(t *testing.T) {
 		})
 	}
 }
+
+func TestCreateExecutor(t *testing.T) {
+	url, err := url.Parse("http://localhost:8080/index.html")
+	if err != nil {
+		t.Fatalf("unable to parse test url: %v", err)
+	}
+	config := cmdtesting.DefaultClientConfig()
+	// First, ensure that no environment variable creates the fallback executor.
+	executor, err := createExecutor(url, config)
+	if err != nil {
+		t.Fatalf("unable to create executor: %v", err)
+	}
+	if _, isFallback := executor.(*remotecommand.FallbackExecutor); !isFallback {
+		t.Errorf("expected fallback executor, got %#v", executor)
+	}
+	// Next, check turning on feature flag explicitly also creates fallback executor.
+	t.Setenv(string(cmdutil.RemoteCommandWebsockets), "true")
+	executor, err = createExecutor(url, config)
+	if err != nil {
+		t.Fatalf("unable to create executor: %v", err)
+	}
+	if _, isFallback := executor.(*remotecommand.FallbackExecutor); !isFallback {
+		t.Errorf("expected fallback executor, got %#v", executor)
+	}
+	// Finally, check explicit disabling does NOT create the fallback executor.
+	t.Setenv(string(cmdutil.RemoteCommandWebsockets), "false")
+	executor, err = createExecutor(url, config)
+	if err != nil {
+		t.Fatalf("unable to create executor: %v", err)
+	}
+	if _, isFallback := executor.(*remotecommand.FallbackExecutor); isFallback {
+		t.Errorf("expected fallback executor, got %#v", executor)
+	}
+}

pkg/cmd/exec/exec.go

@@ -121,23 +121,10 @@ type RemoteExecutor interface {
 type DefaultRemoteExecutor struct{}
 
 func (*DefaultRemoteExecutor) Execute(url *url.URL, config *restclient.Config, stdin io.Reader, stdout, stderr io.Writer, tty bool, terminalSizeQueue remotecommand.TerminalSizeQueue) error {
-	// Legacy SPDY executor is default. If feature gate enabled, fallback
+	exec, err := createExecutor(url, config)
-	// executor attempts websockets first--then SPDY.
-	exec, err := remotecommand.NewSPDYExecutor(config, "POST", url)
 	if err != nil {
 		return err
 	}
-	if cmdutil.RemoteCommandWebsockets.IsEnabled() {
-		// 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
-		}
-		exec, err = remotecommand.NewFallbackExecutor(websocketExec, exec, httpstream.IsUpgradeFailure)
-		if err != nil {
-			return err
-		}
-	}
 	return exec.StreamWithContext(context.Background(), remotecommand.StreamOptions{
 		Stdin:             stdin,
 		Stdout:            stdout,
@@ -147,6 +134,27 @@ func (*DefaultRemoteExecutor) Execute(url *url.URL, config *restclient.Config, s
 	})
 }
 
+// createExecutor returns the Executor or an error if one occurred.
+func createExecutor(url *url.URL, config *restclient.Config) (remotecommand.Executor, error) {
+	exec, err := remotecommand.NewSPDYExecutor(config, "POST", url)
+	if err != nil {
+		return nil, err
+	}
+	// Fallback executor is default, unless feature flag is explicitly disabled.
+	if !cmdutil.RemoteCommandWebsockets.IsDisabled() {
+		// 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 nil, err
+		}
+		exec, err = remotecommand.NewFallbackExecutor(websocketExec, exec, httpstream.IsUpgradeFailure)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return exec, nil
+}
+
 type StreamOptions struct {
 	Namespace     string
 	PodName       string

pkg/cmd/exec/exec_test.go

@@ -33,8 +33,8 @@ import (
 	restclient "k8s.io/client-go/rest"
 	"k8s.io/client-go/rest/fake"
 	"k8s.io/client-go/tools/remotecommand"
-
 	cmdtesting "k8s.io/kubectl/pkg/cmd/testing"
+	cmdutil "k8s.io/kubectl/pkg/cmd/util"
 	"k8s.io/kubectl/pkg/scheme"
 	"k8s.io/kubectl/pkg/util/term"
 )
@@ -402,3 +402,37 @@ func TestSetupTTY(t *testing.T) {
 		t.Errorf("attach stdin, TTY, is a terminal: tty.Out should equal o.Out")
 	}
 }
+
+func TestCreateExecutor(t *testing.T) {
+	url, err := url.Parse("http://localhost:8080/index.html")
+	if err != nil {
+		t.Fatalf("unable to parse test url: %v", err)
+	}
+	config := cmdtesting.DefaultClientConfig()
+	// First, ensure that no environment variable creates the fallback executor.
+	executor, err := createExecutor(url, config)
+	if err != nil {
+		t.Fatalf("unable to create executor: %v", err)
+	}
+	if _, isFallback := executor.(*remotecommand.FallbackExecutor); !isFallback {
+		t.Errorf("expected fallback executor, got %#v", executor)
+	}
+	// Next, check turning on feature flag explicitly also creates fallback executor.
+	t.Setenv(string(cmdutil.RemoteCommandWebsockets), "true")
+	executor, err = createExecutor(url, config)
+	if err != nil {
+		t.Fatalf("unable to create executor: %v", err)
+	}
+	if _, isFallback := executor.(*remotecommand.FallbackExecutor); !isFallback {
+		t.Errorf("expected fallback executor, got %#v", executor)
+	}
+	// Finally, check explicit disabling does NOT create the fallback executor.
+	t.Setenv(string(cmdutil.RemoteCommandWebsockets), "false")
+	executor, err = createExecutor(url, config)
+	if err != nil {
+		t.Fatalf("unable to create executor: %v", err)
+	}
+	if _, isFallback := executor.(*remotecommand.FallbackExecutor); isFallback {
+		t.Errorf("expected fallback executor, got %#v", executor)
+	}
+}