Support for Kubernetes Websocket V5 protocol

[tigrato]

Kubernetes will deprecate the usage of SPDY for IO-related events (attach, exec, port-forward) and will introduce a new websocket protocol (V5).

Teleport must support it as a server and as client.

Draft PR: kubernetes/kubernetes#119157
RFD: kubernetes/enhancements#4016

[tigrato]

This is a tracking issue, for now no action is required since the PR is not yet ready/merged

[ringerc]

If you're getting errors like

websocket._exceptions.WebSocketBadStatusException: Handshake status 500 Internal Server Error

During handling of the above exception, another exception occurred:

...

kubernetes.client.exceptions.ApiException: (0)
Reason: Handshake status 500 Internal Server Error

from the Python kubernetes client when (say) attempting to set up port-forwards, this will be why. Unfortunately the Python client doesn't detect when the kube API server endpoint doesn't support websockets and fail with a more graceful error.

[aviramha]

Is this still relevant?

[AntonAM]

Implemented by #39755