// Defaults to true.
  // +optional
  optional bool stdout = 2;

  // Stderr if true indicates that stderr is to be redirected for the attach call.
  // Defaults to true.
  // +optional
  optional bool stderr = 3;

  // TTY if true indicates that a tty will be allocated for the attach call.
  // This is passed through the container runtime so the tty

- Kubeadm: all warning messages are printed to stderr instead of stdout. ([#107467](https://github.com/kubernetes/kubernetes/pull/107467), [@SataQiu](https://github.com/SataQiu))