<p>I use wscat having successfully established connection with pod container(/bin/bash), but when I send command to it, I received no response from it. Could anyone tell me why?
<a href="https://i.stack.imgur.com/2HhQz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2HhQz.png" alt="enter image description here"></a> </p>

user3398604
<p>Posting @user3398604 solution as community wiki for better visibility:</p>

<blockquote>
  <p>K8S api-server using websocket sub-protocol to exchange data. For
  input(stdin), the protocol requires the payload is heading with '\0'
  byte, not zero, it's ascii zero-valued character. So wscat is limited
  to interacting with k8s pod due to wscat can not send invisible
  character.</p>
</blockquote>
