Stop unconditionally setting cmd to jupyterhub-singleuser

[yuvipanda]

in basehub/values.yaml, we set cmd to jupyterhub-singleuser, to account for images that may not have that correctly set up. However, this means that the ENTRYPOINT set up in the docker image is not run, causing issues with logging when using repo2docker (#3433) as well as startup when using desktop-proxy.

We should evaluate if this is actually still needed, and if not, unset jupyterhub-singleuser as cmd in basehub/values.yaml

[consideRatio]

jupyterhub/kubespawner#493 (comment) has related discussion summarized.

I think the role of jupyterhub-singleuser has changed notably over time, where a key point is to configure notebook and jupyter_server to be jupyterhub aware, but that such awareness in at least jupyter_server of modern versions is handled by environment variables and a jupyter_server extension.

So, unsetting it is probably fine for all images that use jupyter_server of a modern enough version, but probably not for those using notebook as a server still. I think maybe the only use of notebook as a server may be in utoronto.

[consideRatio]

in basehub/values.yaml, we set cmd to jupyterhub-singleuser, to account for images that may not have that correctly set up. However, this means that the ENTRYPOINT set up in the docker image is not run, causing issues with logging when using repo2docker (#3433) as well as startup when using desktop-proxy.

Currently z2jh's default is to set singleuser.cmd (KubeSpawner.cmd) to jupyterhub-singleuser, we don't do it in basehub. Setting it overrides docker images' CMD, but won't override docker images's ENTRYPOINT. I think we are fine with the current state of things and no action is required.

More details on the understanding I have currently is reflected in the PR description for #3797.

[yuvipanda]

fwiw we still definitely do it in basehub:

infrastructure/helm-charts/basehub/values.yaml

Line 282 in a6e5a19

- jupyterhub-singleuser

[yuvipanda]

@consideRatio can this be closed now? I remember you took some actions here, but I'm not sure what.

[consideRatio]

I don't advocate any action related to this issue, so if you think its OK to close lets close!

Logs etc is resolved, but we have via z2jh set singleuser.cmd explicitly, which I think we should.

[yuvipanda]

@consideRatio as long as you don't think we need to actively make any changes, I'm all good! Thanks for closing.