Esempio n. 1
0
// ServeHTTP serves a series of encoded events via HTTP with Transfer-Encoding: chunked
// or over a websocket connection.
func (s *WatchServer) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	w = httplog.Unlogged(w)

	if wsstream.IsWebSocketRequest(req) {
		w.Header().Set("Content-Type", s.MediaType)
		websocket.Handler(s.HandleWS).ServeHTTP(w, req)
		return
	}

	cn, ok := w.(http.CloseNotifier)
	if !ok {
		err := fmt.Errorf("unable to start watch - can't get http.CloseNotifier: %#v", w)
		utilruntime.HandleError(err)
		s.Scope.err(errors.NewInternalError(err), w, req)
		return
	}
	flusher, ok := w.(http.Flusher)
	if !ok {
		err := fmt.Errorf("unable to start watch - can't get http.Flusher: %#v", w)
		utilruntime.HandleError(err)
		s.Scope.err(errors.NewInternalError(err), w, req)
		return
	}

	framer := s.Framer.NewFrameWriter(w)
	if framer == nil {
		// programmer error
		err := fmt.Errorf("no stream framing support is available for media type %q", s.MediaType)
		utilruntime.HandleError(err)
		s.Scope.err(errors.NewBadRequest(err.Error()), w, req)
		return
	}
	e := streaming.NewEncoder(framer, s.Encoder)

	// ensure the connection times out
	timeoutCh, cleanup := s.TimeoutFactory.TimeoutCh()
	defer cleanup()
	defer s.Watching.Stop()

	// begin the stream
	w.Header().Set("Content-Type", s.MediaType)
	w.Header().Set("Transfer-Encoding", "chunked")
	w.WriteHeader(http.StatusOK)
	flusher.Flush()

	var unknown runtime.Unknown
	internalEvent := &metav1.InternalEvent{}
	buf := &bytes.Buffer{}
	ch := s.Watching.ResultChan()
	for {
		select {
		case <-cn.CloseNotify():
			return
		case <-timeoutCh:
			return
		case event, ok := <-ch:
			if !ok {
				// End of results.
				return
			}

			obj := event.Object
			s.Fixup(obj)
			if err := s.EmbeddedEncoder.Encode(obj, buf); err != nil {
				// unexpected error
				utilruntime.HandleError(fmt.Errorf("unable to encode watch object: %v", err))
				return
			}

			// ContentType is not required here because we are defaulting to the serializer
			// type
			unknown.Raw = buf.Bytes()
			event.Object = &unknown

			// the internal event will be versioned by the encoder
			*internalEvent = metav1.InternalEvent(event)
			if err := e.Encode(internalEvent); err != nil {
				utilruntime.HandleError(fmt.Errorf("unable to encode watch object: %v (%#v)", err, e))
				// client disconnect.
				return
			}
			if len(ch) == 0 {
				flusher.Flush()
			}

			buf.Reset()
		}
	}
}
Esempio n. 2
0
// HandleWS implements a websocket handler.
func (s *WatchServer) HandleWS(ws *websocket.Conn) {
	defer ws.Close()
	done := make(chan struct{})

	go func() {
		defer utilruntime.HandleCrash()
		// This blocks until the connection is closed.
		// Client should not send anything.
		wsstream.IgnoreReceives(ws, 0)
		// Once the client closes, we should also close
		close(done)
	}()

	var unknown runtime.Unknown
	internalEvent := &metav1.InternalEvent{}
	buf := &bytes.Buffer{}
	streamBuf := &bytes.Buffer{}
	ch := s.Watching.ResultChan()
	for {
		select {
		case <-done:
			s.Watching.Stop()
			return
		case event, ok := <-ch:
			if !ok {
				// End of results.
				return
			}
			obj := event.Object
			s.Fixup(obj)
			if err := s.EmbeddedEncoder.Encode(obj, buf); err != nil {
				// unexpected error
				utilruntime.HandleError(fmt.Errorf("unable to encode watch object: %v", err))
				return
			}

			// ContentType is not required here because we are defaulting to the serializer
			// type
			unknown.Raw = buf.Bytes()
			event.Object = &unknown

			// the internal event will be versioned by the encoder
			*internalEvent = metav1.InternalEvent(event)
			if err := s.Encoder.Encode(internalEvent, streamBuf); err != nil {
				// encoding error
				utilruntime.HandleError(fmt.Errorf("unable to encode event: %v", err))
				s.Watching.Stop()
				return
			}
			if s.UseTextFraming {
				if err := websocket.Message.Send(ws, streamBuf.String()); err != nil {
					// Client disconnect.
					s.Watching.Stop()
					return
				}
			} else {
				if err := websocket.Message.Send(ws, streamBuf.Bytes()); err != nil {
					// Client disconnect.
					s.Watching.Stop()
					return
				}
			}
			buf.Reset()
			streamBuf.Reset()
		}
	}
}
Esempio n. 3
0
// Encode serializes the provided object to the given writer.
func (s *Serializer) Encode(obj runtime.Object, w io.Writer) error {
	prefixSize := uint64(len(s.prefix))

	var unk runtime.Unknown
	switch t := obj.(type) {
	case *runtime.Unknown:
		estimatedSize := prefixSize + uint64(t.Size())
		data := make([]byte, estimatedSize)
		i, err := t.MarshalTo(data[prefixSize:])
		if err != nil {
			return err
		}
		copy(data, s.prefix)
		_, err = w.Write(data[:prefixSize+uint64(i)])
		return err
	default:
		kind := obj.GetObjectKind().GroupVersionKind()
		unk = runtime.Unknown{
			TypeMeta: runtime.TypeMeta{
				Kind:       kind.Kind,
				APIVersion: kind.GroupVersion().String(),
			},
		}
	}

	switch t := obj.(type) {
	case bufferedMarshaller:
		// this path performs a single allocation during write but requires the caller to implement
		// the more efficient Size and MarshalTo methods
		encodedSize := uint64(t.Size())
		estimatedSize := prefixSize + estimateUnknownSize(&unk, encodedSize)
		data := make([]byte, estimatedSize)

		i, err := unk.NestedMarshalTo(data[prefixSize:], t, encodedSize)
		if err != nil {
			return err
		}

		copy(data, s.prefix)

		_, err = w.Write(data[:prefixSize+uint64(i)])
		return err

	case proto.Marshaler:
		// this path performs extra allocations
		data, err := t.Marshal()
		if err != nil {
			return err
		}
		unk.Raw = data

		estimatedSize := prefixSize + uint64(unk.Size())
		data = make([]byte, estimatedSize)

		i, err := unk.MarshalTo(data[prefixSize:])
		if err != nil {
			return err
		}

		copy(data, s.prefix)

		_, err = w.Write(data[:prefixSize+uint64(i)])
		return err

	default:
		// TODO: marshal with a different content type and serializer (JSON for third party objects)
		return errNotMarshalable{reflect.TypeOf(obj)}
	}
}