Pod attach

[vigoo]

Endpoint:

/api/v1/namespaces/{namespace}/pods/{name}/attach

This is one of the cases where the action in the schema is specified as connect.
This means that the request has to be upgraded to a websocket connection. Both sttp ZIO backends supports websockets so this should be simple to implement. Other than that it is structured like a subresource, so the simplest way to add it is to add support for the connect action for subresources and everything else will be generated automatically.

Very similar to #65 and #66.

It is possible to examine how it works with kubectl attach -v=9.

Example upgrade headers:

X-Stream-Protocol-Version: v4.channel.k8s.io
Date: Sun, 14 Feb 2021 10:28:04 GMT
Connection: Upgrade
Upgrade: SPDY/3.1

Steps to do:

• Implement the connect action by using websockets in Subresource, SubresourceClient and TestSubresourceClient
• Check classification and EndpointType in the code generator, it most likely needs support there too
• Support it in the SubresourceClientGenerator
• Support it in the ClientModuleGenerator
• Remove from codegen whitelist