// 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()
}
}
}
// 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()
}
}
}
// 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)}
}
}