Golang Stream.Reset方法代碼示例

func waitForPortForwardDataStreamAndRun(pod string, uid types.UID, errorStream httpstream.Stream, dataStreamChan chan httpstream.Stream, host HostInterface) {
	defer errorStream.Reset()

	var dataStream httpstream.Stream

	select {
	case dataStream = <-dataStreamChan:
	case <-time.After(streamCreationTimeout):
		errorStream.Write([]byte("Timed out waiting for data stream"))
		//TODO delete from dataStreamChans[port]
		return
	}

	portString := dataStream.Headers().Get(api.PortHeader)
	port, _ := strconv.ParseUint(portString, 10, 16)
	err := host.PortForward(pod, uid, uint16(port), dataStream)
	if err != nil {
		msg := fmt.Errorf("Error forwarding port %d to pod %s, uid %v: %v", port, pod, uid, err)
		glog.Error(msg)
		errorStream.Write([]byte(msg.Error()))
	}
}

//.........這裏部分代碼省略.........
			upgradeRoundTripper = spdy.NewRoundTripper(nil)
			c = &http.Client{Transport: upgradeRoundTripper}
		}

		resp, err = c.Post(url, "", nil)
		if err != nil {
			t.Fatalf("%d: Got error POSTing: %v", i, err)
		}
		defer resp.Body.Close()

		_, err = ioutil.ReadAll(resp.Body)
		if err != nil {
			t.Errorf("%d: Error reading response body: %v", i, err)
		}

		if e, a := test.responseStatusCode, resp.StatusCode; e != a {
			t.Fatalf("%d: response status: expected %v, got %v", i, e, a)
		}

		if test.responseStatusCode != http.StatusSwitchingProtocols {
			continue
		}

		conn, err := upgradeRoundTripper.NewConnection(resp)
		if err != nil {
			t.Fatalf("Unexpected error creating streaming connection: %s", err)
		}
		if conn == nil {
			t.Fatalf("%d: unexpected nil conn", i)
		}
		defer conn.Close()

		h := http.Header{}
		h.Set(api.StreamType, api.StreamTypeError)
		errorStream, err := conn.CreateStream(h)
		if err != nil {
			t.Fatalf("%d: error creating error stream: %v", i, err)
		}
		defer errorStream.Reset()

		if test.stdin {
			h.Set(api.StreamType, api.StreamTypeStdin)
			stream, err := conn.CreateStream(h)
			if err != nil {
				t.Fatalf("%d: error creating stdin stream: %v", i, err)
			}
			defer stream.Reset()
			_, err = stream.Write([]byte(expectedStdin))
			if err != nil {
				t.Fatalf("%d: error writing to stdin stream: %v", i, err)
			}
		}

		var stdoutStream httpstream.Stream
		if test.stdout {
			h.Set(api.StreamType, api.StreamTypeStdout)
			stdoutStream, err = conn.CreateStream(h)
			if err != nil {
				t.Fatalf("%d: error creating stdout stream: %v", i, err)
			}
			defer stdoutStream.Reset()
		}

		var stderrStream httpstream.Stream
		if test.stderr && !test.tty {
			h.Set(api.StreamType, api.StreamTypeStderr)
			stderrStream, err = conn.CreateStream(h)
			if err != nil {
				t.Fatalf("%d: error creating stderr stream: %v", i, err)
			}
			defer stderrStream.Reset()
		}

		if test.stdout {
			output := make([]byte, 10)
			n, err := stdoutStream.Read(output)
			close(clientStdoutReadDone)
			if err != nil {
				t.Fatalf("%d: error reading from stdout stream: %v", i, err)
			}
			if e, a := expectedStdout, string(output[0:n]); e != a {
				t.Fatalf("%d: stdout: expected '%v', got '%v'", i, e, a)
			}
		}

		if test.stderr && !test.tty {
			output := make([]byte, 10)
			n, err := stderrStream.Read(output)
			close(clientStderrReadDone)
			if err != nil {
				t.Fatalf("%d: error reading from stderr stream: %v", i, err)
			}
			if e, a := expectedStderr, string(output[0:n]); e != a {
				t.Fatalf("%d: stderr: expected '%v', got '%v'", i, e, a)
			}
		}

		<-execFuncDone
	}
}

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(6).Infof("Copying %s", s)
		defer glog.V(6).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{}{}
		}
	}

	var (
		err                                                  error
		errorStream, remoteStdin, remoteStdout, remoteStderr httpstream.Stream
	)

	// set up all the streams first
	headers := http.Header{}
	headers.Set(api.StreamType, api.StreamTypeError)
	errorStream, err = conn.CreateStream(headers)
	if err != nil {
		return err
	}
	defer errorStream.Reset()

	// Create all the streams first, then start the copy goroutines. The server doesn't start its copy
	// goroutines until it's received all of the streams. If the client creates the stdin stream and
	// immediately begins copying stdin data to the server, it's possible to overwhelm and wedge the
	// spdy frame handler in the server so that it is full of unprocessed frames. The frames aren't
	// getting processed because the server hasn't started its copying, and it won't do that until it
	// gets all the streams. By creating all the streams first, we ensure that the server is ready to
	// process data before the client starts sending any. See https://issues.k8s.io/16373 for more info.
	if e.stdin != nil {
		headers.Set(api.StreamType, api.StreamTypeStdin)
		remoteStdin, err = conn.CreateStream(headers)
		if err != nil {
			return err
		}
		defer remoteStdin.Reset()
	}

	if e.stdout != nil {
		headers.Set(api.StreamType, api.StreamTypeStdout)
		remoteStdout, err = conn.CreateStream(headers)
		if err != nil {
			return err
		}
		defer remoteStdout.Reset()
	}

	if e.stderr != nil && !e.tty {
		headers.Set(api.StreamType, api.StreamTypeStderr)
		remoteStderr, err = conn.CreateStream(headers)
		if err != nil {
			return err
		}
		defer remoteStderr.Reset()
	}

	// now that all the streams have been created, proceed with reading & copying

	// always read from errorStream
	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
		}
	}()

	if e.stdin != nil {
		// 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++
		go cp(api.StreamTypeStdout, e.stdout, remoteStdout)
	}

	if e.stderr != nil && !e.tty {
		waitCount++
		go cp(api.StreamTypeStderr, e.stderr, remoteStderr)
	}

Loop:
//.........這裏部分代碼省略.........

func (s *Server) createStreams(request *restful.Request, response *restful.Response) (io.Reader, io.WriteCloser, io.WriteCloser, io.WriteCloser, httpstream.Connection, bool, bool) {
	// start at 1 for error stream
	expectedStreams := 1
	if request.QueryParameter(api.ExecStdinParam) == "1" {
		expectedStreams++
	}
	if request.QueryParameter(api.ExecStdoutParam) == "1" {
		expectedStreams++
	}
	tty := request.QueryParameter(api.ExecTTYParam) == "1"
	if !tty && request.QueryParameter(api.ExecStderrParam) == "1" {
		expectedStreams++
	}

	if expectedStreams == 1 {
		response.WriteError(http.StatusBadRequest, fmt.Errorf("you must specify at least 1 of stdin, stdout, stderr"))
		return nil, nil, nil, nil, nil, false, false
	}

	streamCh := make(chan httpstream.Stream)

	upgrader := spdy.NewResponseUpgrader()
	conn := upgrader.UpgradeResponse(response.ResponseWriter, request.Request, func(stream httpstream.Stream) error {
		streamCh <- stream
		return nil
	})
	// from this point on, we can no longer call methods on response
	if conn == nil {
		// The upgrader is responsible for notifying the client of any errors that
		// occurred during upgrading. All we can do is return here at this point
		// if we weren't successful in upgrading.
		return nil, nil, nil, nil, nil, false, false
	}

	conn.SetIdleTimeout(s.host.StreamingConnectionIdleTimeout())

	// TODO make it configurable?
	expired := time.NewTimer(streamCreationTimeout)

	var errorStream, stdinStream, stdoutStream, stderrStream httpstream.Stream
	receivedStreams := 0
WaitForStreams:
	for {
		select {
		case stream := <-streamCh:
			streamType := stream.Headers().Get(api.StreamType)
			switch streamType {
			case api.StreamTypeError:
				errorStream = stream
				defer errorStream.Reset()
				receivedStreams++
			case api.StreamTypeStdin:
				stdinStream = stream
				receivedStreams++
			case api.StreamTypeStdout:
				stdoutStream = stream
				receivedStreams++
			case api.StreamTypeStderr:
				stderrStream = stream
				receivedStreams++
			default:
				glog.Errorf("Unexpected stream type: '%s'", streamType)
			}
			if receivedStreams == expectedStreams {
				break WaitForStreams
			}
		case <-expired.C:
			// TODO find a way to return the error to the user. Maybe use a separate
			// stream to report errors?
			glog.Error("Timed out waiting for client to create streams")
			return nil, nil, nil, nil, nil, false, false
		}
	}

	if stdinStream != nil {
		// close our half of the input stream, since we won't be writing to it
		stdinStream.Close()
	}

	return stdinStream, stdoutStream, stderrStream, errorStream, conn, tty, true
}