Cannot pod.exec(...) with stdin

[JanPokorny]

Which project are you reporting a bug for?

kr8s

What happened?

I tried using pod.exec with stdin, but got an error message AttributeError: 'AsyncWebSocketSession' object has no attribute 'protocol' from this line:

kr8s/kr8s/_exec.py

Line 73 in 3d7ac19

f"{ws.protocol}, only with v5.channel.k8s.io"

-- clearly that's just a typo, protocol should be subprotocol in the error message.

It seems like the only passed protocol is the v4 one (

kr8s/kr8s/_exec.py

Line 21 in 3d7ac19

EXEC_PROTOCOL = "v4.channel.k8s.io"

) -- which is weird, the error message seems to suggest that there's some way to switch to v5. But given the skipped test (

kr8s/kr8s/tests/test_objects.py

Line 876 in 3d7ac19

@pytest.mark.xfail(reason="Exec protocol v5.channel.k8s.io not available")

) I suppose there isn't?

I saw no tracking issue, so I am reporting this even though the underlying issue seems to be already known.

Anything else?

No response

[jacobtomlinson]

I think this is sort of a duplicate of #212 so I'm going to close this out here. Currently using stdin with exec is just broken with the websockets API in Kubernetes. We need a solution to be released upstream in Kubernetes.

[JanPokorny]

@jacobtomlinson Is it possible to have the "less broken" behavior in the meantime? Eg. what the official library does -- can pass stdin, but it can't be closed client-side.

I'm currently using the official library with a workaround -- closing the input server-side by piping the input through /usr/bin/sed '/\\x0/Q' and sending a null byte at the end, which works for my use case since I send only text.

[jacobtomlinson]

I'd be happy to make it possible to opt into using stdin, but given that users will undoubtedly fall into the trap of trying and failing to close the stream on the client side I'd like to think of a way for users to explicitly opting into this.

I can think of a few options:

• We raise a warning, but this may be a bit noisy.
• We add a flag that has to be set to opt-in

PRs with a proposal would be very welcome here.