Close proxy's backend request earlier when re-connecting for websocket

middleware/proxy/reverseproxy.go

@@ -155,9 +155,9 @@ func (p *ReverseProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request, extr
 	if err != nil {
 		return err
 	}
-	defer res.Body.Close()
 
 	if res.StatusCode == http.StatusSwitchingProtocols && res.Header.Get("Upgrade") == "websocket" {
+		res.Body.Close()
 		hj, ok := rw.(http.Hijacker)
 		if !ok {
 			return nil
@@ -182,6 +182,7 @@ func (p *ReverseProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request, extr
 		}()
 		io.Copy(conn, backendConn) // read tcp stream from backend.
 	} else {
+		defer res.Body.Close()
 		for _, h := range hopHeaders {
 			res.Header.Del(h)
 		}