message: Fail on ws proxying to trigger the polling fallback mechanism
diff: @@ -83,7 +83,12 @@ pub async fn proxy(mut req: Request<Body>, default_ca_data: Vec<u8>) -> Result<R
  match client.request(req).await {
  Ok(r) => {
  info!("{}", logging::response_log_data(&r, log_data));
  + if r.status() == StatusCode::SWITCHING_PROTOCOLS {
  + // TODO(agamez): implement ws proxing here; see https://github.com/kubeapps/kubeapps/issues/2328
  + Ok(Response::builder().status(StatusCode::NOT_IMPLEMENTED).body(Body::from("pinniped-proxy does not support websockets yet")).unwrap())
  + } else {
  Ok(r)
  + }
  },
  Err(e) => return handle_error(anyhow::anyhow!(e), StatusCode::INTERNAL_SERVER_ERROR, log_data),
  }
  