title: Websockets not working in Chrome (wss): “handshake was canceled”
body: <p>I am currently developing a Websocket application on Docker Cloud. When redeploying my application and now I am always getting this error message:</p>
  
  <blockquote>
    <p>WebSocket connection failed: WebSocket opening handshake was canceled</p>
  </blockquote>
  
  <p>When looking into the data frame i see a single frame with this data:</p>
  
  <blockquote>
    <p>(Opcode -1)</p>
  </blockquote>
  
  <p>When researching the issue, it seems that is related to SSL / Certificates etc. Some solutions include adding self signed certificates. The confusing thing is that the same certificates seem to work for https but not for wss:</p>
  
  <p><a href="https://i.stack.imgur.com/19rdK.png" rel="noreferrer"><img src="https://i.stack.imgur.com/19rdK.png" alt="HTTPS works fine"></a></p>
  
  <p>Also while testing with other browsers, I see that Safari is working fine. So I am sure that the server is actually running with the correct certificate on the correct port. Only chrome seems to have issues with it.</p>
  
  <p>I know some solutions on stack overflow sugesst to add the certificate manually, but since it works on Safari and it is not a self signed certificate, I would assume it should just work.</p>