Add streaming subprotocol negotiation

Add streaming subprotocol negotiation for exec, attach, and port
forwarding. Restore previous (buggy) exec functionality as an
unspecified/unversioned subprotocol so newer kubectl clients can work
against 1.0.x kubelets.

pkg/client/unversioned/portforward/portforward.go

@@ -122,13 +122,16 @@ func New(dialer httpstream.Dialer, ports []string, stopChan <-chan struct{}) (*P
 	}, nil
 }
 
+// The SPDY subprotocol "portforward.k8s.io" is used for port forwarding.
+const PortForwardProtocolV1Name = "portforward.k8s.io"
+
 // ForwardPorts formats and executes a port forwarding request. The connection will remain
 // open until stopChan is closed.
 func (pf *PortForwarder) ForwardPorts() error {
 	defer pf.Close()
 
 	var err error
-	pf.streamConn, err = pf.dialer.Dial()
+	pf.streamConn, _, err = pf.dialer.Dial([]string{PortForwardProtocolV1Name})
 	if err != nil {
 		return fmt.Errorf("error upgrading connection: %s", err)
 	}

pkg/client/unversioned/portforward/portforward_test.go

@@ -38,14 +38,15 @@ import (
 )
 
 type fakeDialer struct {
-	dialed bool
-	conn   httpstream.Connection
-	err    error
+	dialed             bool
+	conn               httpstream.Connection
+	err                error
+	negotiatedProtocol string
 }
 
-func (d *fakeDialer) Dial() (httpstream.Connection, error) {
+func (d *fakeDialer) Dial(protocols []string) (httpstream.Connection, string, error) {
 	d.dialed = true
-	return d.conn, d.err
+	return d.conn, d.negotiatedProtocol, d.err
 }
 
 func TestParsePortsAndNew(t *testing.T) {

pkg/client/unversioned/remotecommand/remotecommand.go

@@ -24,6 +24,8 @@ import (
 	"net/url"
 	"sync"
 
+	"github.com/golang/glog"
+
 	"k8s.io/kubernetes/pkg/api"
 	client "k8s.io/kubernetes/pkg/client/unversioned"
 	"k8s.io/kubernetes/pkg/util"
@@ -97,51 +99,207 @@ func NewStreamExecutor(upgrader httpstream.UpgradeRoundTripper, fn func(http.Rou
 	}, nil
 }
 
-// Dial opens a connection to a remote server and attempts to negotiate a SPDY connection.
-func (e *streamExecutor) Dial() (httpstream.Connection, error) {
-	client := &http.Client{Transport: e.transport}
+// Dial opens a connection to a remote server and attempts to negotiate a SPDY
+// connection. Upon success, it returns the connection and the protocol
+// selected by the server.
+func (e *streamExecutor) Dial(protocols []string) (httpstream.Connection, string, error) {
+	transport := e.transport
+	// TODO consider removing this and reusing client.TransportFor above to get this for free
+	switch {
+	case bool(glog.V(9)):
+		transport = client.NewDebuggingRoundTripper(transport, client.CurlCommand, client.URLTiming, client.ResponseHeaders)
+	case bool(glog.V(8)):
+		transport = client.NewDebuggingRoundTripper(transport, client.JustURL, client.RequestHeaders, client.ResponseStatus, client.ResponseHeaders)
+	case bool(glog.V(7)):
+		transport = client.NewDebuggingRoundTripper(transport, client.JustURL, client.RequestHeaders, client.ResponseStatus)
+	case bool(glog.V(6)):
+		transport = client.NewDebuggingRoundTripper(transport, client.URLTiming)
+	}
+	client := &http.Client{Transport: transport}
 
 	req, err := http.NewRequest(e.method, e.url.String(), nil)
 	if err != nil {
-		return nil, fmt.Errorf("error creating request: %s", err)
+		return nil, "", fmt.Errorf("error creating request: %v", err)
+	}
+	for i := range protocols {
+		req.Header.Add(httpstream.HeaderProtocolVersion, protocols[i])
 	}
 
 	resp, err := client.Do(req)
 	if err != nil {
-		return nil, fmt.Errorf("error sending request: %s", err)
+		return nil, "", fmt.Errorf("error sending request: %v", err)
 	}
 	defer resp.Body.Close()
 
-	// TODO: handle protocol selection in the future
-	return e.upgrader.NewConnection(resp)
+	if resp.StatusCode != http.StatusSwitchingProtocols {
+		return nil, "", fmt.Errorf("unexpected response status code %d (%s)", resp.StatusCode, http.StatusText(resp.StatusCode))
+	}
+
+	conn, err := e.upgrader.NewConnection(resp)
+	if err != nil {
+		return nil, "", err
+	}
+
+	return conn, resp.Header.Get(httpstream.HeaderProtocolVersion), nil
+}
+
+const (
+	// The SPDY subprotocol "channel.k8s.io" is used for remote command
+	// attachment/execution. This represents the initial unversioned subprotocol,
+	// which has the known bugs http://issues.k8s.io/13394 and
+	// http://issues.k8s.io/13395.
+	StreamProtocolV1Name = "channel.k8s.io"
+	// The SPDY subprotocol "v2.channel.k8s.io" is used for remote command
+	// attachment/execution. It is the second version of the subprotocol and
+	// resolves the issues present in the first version.
+	StreamProtocolV2Name = "v2.channel.k8s.io"
+)
+
+type streamProtocolHandler interface {
+	stream(httpstream.Connection) error
 }
 
 // Stream opens a protocol streamer to the server and streams until a client closes
 // the connection or the server disconnects.
 func (e *streamExecutor) Stream(stdin io.Reader, stdout, stderr io.Writer, tty bool) error {
-	conn, err := e.Dial()
+	conn, protocol, err := e.Dial([]string{StreamProtocolV2Name, StreamProtocolV1Name})
 	if err != nil {
 		return err
 	}
 	defer conn.Close()
-	// TODO: negotiate protocols
-	streamer := &streamProtocol{
-		stdin:  stdin,
-		stdout: stdout,
-		stderr: stderr,
-		tty:    tty,
+
+	var streamer streamProtocolHandler
+
+	switch protocol {
+	case StreamProtocolV2Name:
+		streamer = &streamProtocolV2{
+			stdin:  stdin,
+			stdout: stdout,
+			stderr: stderr,
+			tty:    tty,
+		}
+	case "":
+		glog.Warning("The server did not negotiate a streaming protocol version. Falling back to unversioned")
+		// TODO restore v1
+		streamer = &streamProtocolV1{
+			stdin:  stdin,
+			stdout: stdout,
+			stderr: stderr,
+			tty:    tty,
+		}
 	}
+
 	return streamer.stream(conn)
 }
 
-type streamProtocol struct {
+type streamProtocolV1 struct {
 	stdin  io.Reader
 	stdout io.Writer
 	stderr io.Writer
 	tty    bool
 }
 
-func (e *streamProtocol) stream(conn httpstream.Connection) error {
+func (e *streamProtocolV1) stream(conn httpstream.Connection) error {
+	doneChan := make(chan struct{}, 2)
+	errorChan := make(chan error)
+
+	cp := func(s string, dst io.Writer, src io.Reader) {
+		glog.V(4).Infof("Copying %s", s)
+		defer glog.V(4).Infof("Done copying %s", s)
+		if _, err := io.Copy(dst, src); err != nil && err != io.EOF {
+			glog.Errorf("Error copying %s: %v", s, err)
+		}
+		if s == api.StreamTypeStdout || s == api.StreamTypeStderr {
+			doneChan <- struct{}{}
+		}
+	}
+
+	headers := http.Header{}
+	headers.Set(api.StreamType, api.StreamTypeError)
+	errorStream, err := conn.CreateStream(headers)
+	if err != nil {
+		return err
+	}
+	go func() {
+		message, err := ioutil.ReadAll(errorStream)
+		if err != nil && err != io.EOF {
+			errorChan <- fmt.Errorf("Error reading from error stream: %s", err)
+			return
+		}
+		if len(message) > 0 {
+			errorChan <- fmt.Errorf("Error executing remote command: %s", message)
+			return
+		}
+	}()
+	defer errorStream.Reset()
+
+	if e.stdin != nil {
+		headers.Set(api.StreamType, api.StreamTypeStdin)
+		remoteStdin, err := conn.CreateStream(headers)
+		if err != nil {
+			return err
+		}
+		defer remoteStdin.Reset()
+		// TODO this goroutine will never exit cleanly (the io.Copy never unblocks)
+		// because stdin is not closed until the process exits. If we try to call
+		// stdin.Close(), it returns no error but doesn't unblock the copy. It will
+		// exit when the process exits, instead.
+		go cp(api.StreamTypeStdin, remoteStdin, e.stdin)
+	}
+
+	waitCount := 0
+	completedStreams := 0
+
+	if e.stdout != nil {
+		waitCount++
+		headers.Set(api.StreamType, api.StreamTypeStdout)
+		remoteStdout, err := conn.CreateStream(headers)
+		if err != nil {
+			return err
+		}
+		defer remoteStdout.Reset()
+		go cp(api.StreamTypeStdout, e.stdout, remoteStdout)
+	}
+
+	if e.stderr != nil && !e.tty {
+		waitCount++
+		headers.Set(api.StreamType, api.StreamTypeStderr)
+		remoteStderr, err := conn.CreateStream(headers)
+		if err != nil {
+			return err
+		}
+		defer remoteStderr.Reset()
+		go cp(api.StreamTypeStderr, e.stderr, remoteStderr)
+	}
+
+Loop:
+	for {
+		select {
+		case <-doneChan:
+			completedStreams++
+			if completedStreams == waitCount {
+				break Loop
+			}
+		case err := <-errorChan:
+			return err
+		}
+	}
+
+	return nil
+}
+
+// streamProtocolV2 implements version 2 of the streaming protocol for attach
+// and exec. The original streaming protocol was unversioned. As a result, this
+// version is referred to as version 2, even though it is the first actual
+// numbered version.
+type streamProtocolV2 struct {
+	stdin  io.Reader
+	stdout io.Writer
+	stderr io.Writer
+	tty    bool
+}
+
+func (e *streamProtocolV2) stream(conn httpstream.Connection) error {
 	headers := http.Header{}
 
 	// set up error stream

pkg/client/unversioned/remotecommand/remotecommand_test.go

@@ -45,7 +45,7 @@ func fakeExecServer(t *testing.T, i int, stdinData, stdoutData, stderrData, erro
 		streamCh := make(chan httpstream.Stream)
 
 		upgrader := spdy.NewResponseUpgrader()
-		conn := upgrader.UpgradeResponse(w, req, func(stream httpstream.Stream) error {
+		conn, protocol := upgrader.UpgradeResponse(w, req, []string{StreamProtocolV2Name, StreamProtocolV1Name}, func(stream httpstream.Stream) error {
 			streamCh <- stream
 			return nil
 		})
@@ -57,6 +57,7 @@ func fakeExecServer(t *testing.T, i int, stdinData, stdoutData, stderrData, erro
 			return
 		}
 		defer conn.Close()
+		_ = protocol
 
 		var errorStream, stdinStream, stdoutStream, stderrStream httpstream.Stream
 		receivedStreams := 0
@@ -347,7 +348,7 @@ func TestDial(t *testing.T) {
 		checkResponse: true,
 		conn:          &fakeConnection{},
 		resp: &http.Response{
-			StatusCode: http.StatusOK,
+			StatusCode: http.StatusSwitchingProtocols,
 			Body:       ioutil.NopCloser(&bytes.Buffer{}),
 		},
 	}
@@ -363,7 +364,7 @@ func TestDial(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	conn, err := exec.Dial()
+	conn, protocol, err := exec.Dial([]string{"a", "b"})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -373,4 +374,5 @@ func TestDial(t *testing.T) {
 	if !called {
 		t.Errorf("wrapper not called")
 	}
+	_ = protocol
 }

pkg/kubelet/server.go

@@ -44,6 +44,8 @@ import (
 	"k8s.io/kubernetes/pkg/api/validation"
 	"k8s.io/kubernetes/pkg/auth/authenticator"
 	"k8s.io/kubernetes/pkg/auth/authorizer"
+	"k8s.io/kubernetes/pkg/client/unversioned/portforward"
+	"k8s.io/kubernetes/pkg/client/unversioned/remotecommand"
 	"k8s.io/kubernetes/pkg/healthz"
 	"k8s.io/kubernetes/pkg/httplog"
 	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
@@ -688,7 +690,7 @@ func (s *Server) createStreams(request *restful.Request, response *restful.Respo
 	streamCh := make(chan httpstream.Stream)
 
 	upgrader := spdy.NewResponseUpgrader()
-	conn := upgrader.UpgradeResponse(response.ResponseWriter, request.Request, func(stream httpstream.Stream) error {
+	conn, protocol := upgrader.UpgradeResponse(response.ResponseWriter, request.Request, []string{remotecommand.StreamProtocolV2Name, remotecommand.StreamProtocolV1Name}, func(stream httpstream.Stream) error {
 		streamCh <- stream
 		return nil
 	})
@@ -699,6 +701,9 @@ func (s *Server) createStreams(request *restful.Request, response *restful.Respo
 		// if we weren't successful in upgrading.
 		return nil, nil, nil, nil, nil, false, false
 	}
+	if len(protocol) == 0 {
+		protocol = remotecommand.StreamProtocolV1Name
+	}
 
 	conn.SetIdleTimeout(s.host.StreamingConnectionIdleTimeout())
 
@@ -783,12 +788,14 @@ func ServePortForward(w http.ResponseWriter, req *http.Request, portForwarder Po
 
 	glog.V(5).Infof("Upgrading port forward response")
 	upgrader := spdy.NewResponseUpgrader()
-	conn := upgrader.UpgradeResponse(w, req, portForwardStreamReceived(streamChan))
+	conn, protocol := upgrader.UpgradeResponse(w, req, []string{portforward.PortForwardProtocolV1Name}, portForwardStreamReceived(streamChan))
 	if conn == nil {
 		return
 	}
 	defer conn.Close()
 
+	_ = protocol
+
 	glog.V(5).Infof("(conn=%p) setting port forwarding streaming connection idle timeout to %v", conn, idleTimeout)
 	conn.SetIdleTimeout(idleTimeout)
 

pkg/util/httpstream/httpstream.go

@@ -24,8 +24,9 @@ import (
 )
 
 const (
-	HeaderConnection = "Connection"
-	HeaderUpgrade    = "Upgrade"
+	HeaderConnection      = "Connection"
+	HeaderUpgrade         = "Upgrade"
+	HeaderProtocolVersion = "X-Stream-Protocol-Version"
 )
 
 // NewStreamHandler defines a function that is called when a new Stream is
@@ -39,7 +40,10 @@ func NoOpNewStreamHandler(stream Stream) error { return nil }
 
 // Dialer knows how to open a streaming connection to a server.
 type Dialer interface {
-	Dial() (Connection, error)
+
+	// Dial opens a streaming connection to a server using one of the protocols
+	// specified (in order of most preferred to least preferred).
+	Dial(protocols []string) (Connection, string, error)
 }
 
 // UpgradeRoundTripper is a type of http.RoundTripper that is able to upgrade
@@ -58,7 +62,7 @@ type ResponseUpgrader interface {
 	// UpgradeResponse upgrades an HTTP response to one that supports multiplexed
 	// streams. newStreamHandler will be called synchronously whenever the
 	// other end of the upgraded connection creates a new stream.
-	UpgradeResponse(w http.ResponseWriter, req *http.Request, newStreamHandler NewStreamHandler) Connection
+	UpgradeResponse(w http.ResponseWriter, req *http.Request, protocols []string, newStreamHandler NewStreamHandler) (Connection, string)
 }
 
 // Connection represents an upgraded HTTP connection.

pkg/util/httpstream/spdy/roundtripper_test.go

@@ -120,7 +120,7 @@ func TestRoundTripAndNewConnection(t *testing.T) {
 			streamCh := make(chan httpstream.Stream)
 
 			responseUpgrader := NewResponseUpgrader()
-			spdyConn := responseUpgrader.UpgradeResponse(w, req, func(s httpstream.Stream) error {
+			spdyConn, _ := responseUpgrader.UpgradeResponse(w, req, []string{"protocol1"}, func(s httpstream.Stream) error {
 				streamCh <- s
 				return nil
 			})

pkg/util/httpstream/spdy/upgrade.go

@@ -39,23 +39,47 @@ func NewResponseUpgrader() httpstream.ResponseUpgrader {
 	return responseUpgrader{}
 }
 
+func negotiateProtocol(clientProtocols, serverProtocols []string) string {
+	for i := range clientProtocols {
+		for j := range serverProtocols {
+			if clientProtocols[i] == serverProtocols[j] {
+				return clientProtocols[i]
+			}
+		}
+	}
+	return ""
+}
+
 // UpgradeResponse upgrades an HTTP response to one that supports multiplexed
 // streams. newStreamHandler will be called synchronously whenever the
 // other end of the upgraded connection creates a new stream.
-func (u responseUpgrader) UpgradeResponse(w http.ResponseWriter, req *http.Request, newStreamHandler httpstream.NewStreamHandler) httpstream.Connection {
+func (u responseUpgrader) UpgradeResponse(w http.ResponseWriter, req *http.Request, protocols []string, newStreamHandler httpstream.NewStreamHandler) (httpstream.Connection, string) {
 	connectionHeader := strings.ToLower(req.Header.Get(httpstream.HeaderConnection))
 	upgradeHeader := strings.ToLower(req.Header.Get(httpstream.HeaderUpgrade))
 	if !strings.Contains(connectionHeader, strings.ToLower(httpstream.HeaderUpgrade)) || !strings.Contains(upgradeHeader, strings.ToLower(HeaderSpdy31)) {
-		w.Write([]byte(fmt.Sprintf("Unable to upgrade: missing upgrade headers in request: %#v", req.Header)))
 		w.WriteHeader(http.StatusBadRequest)
-		return nil
+		fmt.Fprintf(w, "unable to upgrade: missing upgrade headers in request: %#v", req.Header)
+		return nil, ""
 	}
 
 	hijacker, ok := w.(http.Hijacker)
 	if !ok {
-		w.Write([]byte("Unable to upgrade: unable to hijack response"))
 		w.WriteHeader(http.StatusInternalServerError)
-		return nil
+		fmt.Fprintf(w, "unable to upgrade: unable to hijack response")
+		return nil, ""
+	}
+
+	var negotiatedProtocol string
+	clientProtocols := req.Header[http.CanonicalHeaderKey(httpstream.HeaderProtocolVersion)]
+	if len(clientProtocols) > 0 {
+		negotiatedProtocol = negotiateProtocol(req.Header[http.CanonicalHeaderKey(httpstream.HeaderProtocolVersion)], protocols)
+		if len(negotiatedProtocol) > 0 {
+			w.Header().Add(httpstream.HeaderProtocolVersion, negotiatedProtocol)
+		} else {
+			w.WriteHeader(http.StatusForbidden)
+			fmt.Fprintf(w, "unable to upgrade: unable to negotiate protocol: server accepts %v", protocols)
+			return nil, ""
+		}
 	}
 
 	w.Header().Add(httpstream.HeaderConnection, httpstream.HeaderUpgrade)
@@ -64,15 +88,15 @@ func (u responseUpgrader) UpgradeResponse(w http.ResponseWriter, req *http.Reque
 
 	conn, _, err := hijacker.Hijack()
 	if err != nil {
-		glog.Errorf("Unable to upgrade: error hijacking response: %v", err)
-		return nil
+		glog.Errorf("unable to upgrade: error hijacking response: %v", err)
+		return nil, ""
 	}
 
 	spdyConn, err := NewServerConnection(conn, newStreamHandler)
 	if err != nil {
-		glog.Errorf("Unable to upgrade: error creating SPDY server connection: %v", err)
-		return nil
+		glog.Errorf("unable to upgrade: error creating SPDY server connection: %v", err)
+		return nil, ""
 	}
 
-	return spdyConn
+	return spdyConn, negotiatedProtocol
 }

pkg/util/httpstream/spdy/upgrade_test.go

@@ -53,7 +53,8 @@ func TestUpgradeResponse(t *testing.T) {
 	for i, testCase := range testCases {
 		server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 			upgrader := NewResponseUpgrader()
-			conn := upgrader.UpgradeResponse(w, req, nil)
+			conn, protocol := upgrader.UpgradeResponse(w, req, []string{"protocol1"}, nil)
+			_ = protocol
 			haveErr := conn == nil
 			if e, a := testCase.shouldError, haveErr; e != a {
 				t.Fatalf("%d: expected shouldErr=%t, got %t", i, testCase.shouldError, haveErr)