// connectBackend dials the backend at location and forwards a copy of the client request.
func (h *UpgradeAwareProxyHandler) connectBackend(method string, location *url.URL, header http.Header, body io.Reader) (conn net.Conn, err error) {
defer func() {
if err != nil && conn != nil {
conn.Close()
conn = nil
}
}()
beReq, err := http.NewRequest(method, location.String(), body)
if err != nil {
return nil, err
}
beReq.Header = header
conn, err = proxy.DialURL(location, h.Transport)
if err != nil {
return conn, fmt.Errorf("error dialing backend: %v", err)
}
if err = beReq.Write(conn); err != nil {
return conn, fmt.Errorf("error sending request: %v", err)
}
return conn, err
}
// tryUpgrade returns true if the request was handled.
func (r *ProxyHandler) tryUpgrade(w http.ResponseWriter, req, newReq *http.Request, location *url.URL, transport http.RoundTripper) bool {
if !httpstream.IsUpgradeRequest(req) {
return false
}
backendConn, err := proxyutil.DialURL(location, transport)
if err != nil {
status := errToAPIStatus(err)
code := int(status.Code)
writeJSON(code, r.codec, status, w, true)
return true
}
defer backendConn.Close()
// TODO should we use _ (a bufio.ReadWriter) instead of requestHijackedConn
// when copying between the client and the backend? Docker doesn't when they
// hijack, just for reference...
requestHijackedConn, _, err := w.(http.Hijacker).Hijack()
if err != nil {
status := errToAPIStatus(err)
code := int(status.Code)
writeJSON(code, r.codec, status, w, true)
return true
}
defer requestHijackedConn.Close()
if err = newReq.Write(backendConn); err != nil {
status := errToAPIStatus(err)
code := int(status.Code)
writeJSON(code, r.codec, status, w, true)
return true
}
done := make(chan struct{}, 2)
go func() {
_, err := io.Copy(backendConn, requestHijackedConn)
if err != nil && !strings.Contains(err.Error(), "use of closed network connection") {
glog.Errorf("Error proxying data from client to backend: %v", err)
}
done <- struct{}{}
}()
go func() {
_, err := io.Copy(requestHijackedConn, backendConn)
if err != nil && !strings.Contains(err.Error(), "use of closed network connection") {
glog.Errorf("Error proxying data from backend to client: %v", err)
}
done <- struct{}{}
}()
<-done
return true
}
// tryUpgrade returns true if the request was handled.
func (h *UpgradeAwareProxyHandler) tryUpgrade(w http.ResponseWriter, req *http.Request) bool {
if !httpstream.IsUpgradeRequest(req) {
return false
}
backendConn, err := proxy.DialURL(h.Location, h.Transport)
if err != nil {
h.Responder.Error(err)
return true
}
defer backendConn.Close()
requestHijackedConn, _, err := w.(http.Hijacker).Hijack()
if err != nil {
h.Responder.Error(err)
return true
}
defer requestHijackedConn.Close()
newReq, err := http.NewRequest(req.Method, h.Location.String(), req.Body)
if err != nil {
h.Responder.Error(err)
return true
}
newReq.Header = req.Header
if err = newReq.Write(backendConn); err != nil {
h.Responder.Error(err)
return true
}
wg := &sync.WaitGroup{}
wg.Add(2)
go func() {
var writer io.WriteCloser
if h.MaxBytesPerSec > 0 {
writer = flowrate.NewWriter(backendConn, h.MaxBytesPerSec)
} else {
writer = backendConn
}
_, err := io.Copy(writer, requestHijackedConn)
if err != nil && !strings.Contains(err.Error(), "use of closed network connection") {
glog.Errorf("Error proxying data from client to backend: %v", err)
}
wg.Done()
}()
go func() {
var reader io.ReadCloser
if h.MaxBytesPerSec > 0 {
reader = flowrate.NewReader(backendConn, h.MaxBytesPerSec)
} else {
reader = backendConn
}
_, err := io.Copy(requestHijackedConn, reader)
if err != nil && !strings.Contains(err.Error(), "use of closed network connection") {
glog.Errorf("Error proxying data from backend to client: %v", err)
}
wg.Done()
}()
wg.Wait()
return true
}