// requestID returns the request id for stream.
func (h *portForwardStreamHandler) requestID(stream httpstream.Stream) string {
requestID := stream.Headers().Get(api.PortForwardRequestIDHeader)
if len(requestID) == 0 {
glog.V(5).Infof("(conn=%p) stream received without %s header", h.conn, api.PortForwardRequestIDHeader)
// If we get here, it's because the connection came from an older client
// that isn't generating the request id header
// (https://github.com/kubernetes/kubernetes/blob/843134885e7e0b360eb5441e85b1410a8b1a7a0c/pkg/client/unversioned/portforward/portforward.go#L258-L287)
//
// This is a best-effort attempt at supporting older clients.
//
// When there aren't concurrent new forwarded connections, each connection
// will have a pair of streams (data, error), and the stream IDs will be
// consecutive odd numbers, e.g. 1 and 3 for the first connection. Convert
// the stream ID into a pseudo-request id by taking the stream type and
// using id = stream.Identifier() when the stream type is error,
// and id = stream.Identifier() - 2 when it's data.
//
// NOTE: this only works when there are not concurrent new streams from
// multiple forwarded connections; it's a best-effort attempt at supporting
// old clients that don't generate request ids. If there are concurrent
// new connections, it's possible that 1 connection gets streams whose IDs
// are not consecutive (e.g. 5 and 9 instead of 5 and 7).
streamType := stream.Headers().Get(api.StreamType)
switch streamType {
case api.StreamTypeError:
requestID = strconv.Itoa(int(stream.Identifier()))
case api.StreamTypeData:
requestID = strconv.Itoa(int(stream.Identifier()) - 2)
}
glog.V(5).Infof("(conn=%p) automatically assigning request ID=%q from stream type=%s, stream ID=%d", h.conn, requestID, streamType, stream.Identifier())
}
return requestID
}
// add adds the stream to the portForwardStreamPair. If the pair already
// contains a stream for the new stream's type, an error is returned. add
// returns true if both the data and error streams for this pair have been
// received.
func (p *portForwardStreamPair) add(stream httpstream.Stream) (bool, error) {
p.lock.Lock()
defer p.lock.Unlock()
switch stream.Headers().Get(api.StreamType) {
case api.StreamTypeError:
if p.errorStream != nil {
return false, errors.New("error stream already assigned")
}
p.errorStream = stream
case api.StreamTypeData:
if p.dataStream != nil {
return false, errors.New("data stream already assigned")
}
p.dataStream = stream
}
complete := p.errorStream != nil && p.dataStream != nil
if complete {
close(p.complete)
}
return complete, nil
}