Parameter "singleuser.defaultUrl" not working

[AdrianSanchezLopez]

Bug description

With the lastest version of the Helm chart 2.0.0, the parameter "singleuser.defaultUrl" does not work. Setting it to "/lab" previously redirected the single-user servers to JupyterLab, now it opens the regular jupyter notebook

Expected behaviour

Redirect the user's address to /lab when setting singleuser.defaultUrl: "/lab"

Actual behaviour

It does not redirect to /lab, but instead to "/tree", the regular jupyter notebook

How to reproduce

1. Deploy helm chart 1.2 with singleuser.defaultUrl: "/lab"
2. Start a User server: it gets redirected to "/lab"
3. Deploy helm chart 2.0.0 with singleuser.defaultUrl: "/lab"
4. Start a User server: it gets redirected to "tree"

Your personal set up

Tested with minikube version: v1.24.0
kubectl version

Client Version: version.Info{Major:"1", Minor:"22", GitVersion:"v1.22.4", GitCommit:"b695d79d4f967c403a96986f1750a35eb75e75f1", GitTreeState:"clean", BuildDate:"2021-11-17T15:48:33Z", GoVersion:"go1.16.10", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"22", GitVersion:"v1.22.3", GitCommit:"c92036820499fedefec0f847e2054d824aea6cd1", GitTreeState:"clean", BuildDate:"2021-10-27T18:35:25Z", GoVersion:"go1.16.9", Compiler:"gc", Platform:"linux/amd64"}

[manics]

Please can you show us your full Z2JH config? Is you singleuser server up-to-date?

[consideRatio]

This can be influenced by various things in both your config and image.

1. Have you in any way changed your singleuser.image since upgrading, or can we assume its unrelated to the image?
2. What does your singleuser.cmd specify?

Overall, this is a very tricky configuration, and we've dwelled on how to make things work well in jupyterhub/kubespawner#493 (comment). I think there may be a quickfix of making sure that you have singleuser.cmd set to something, such as the default value of the Helm chart. In other words, to not override that with a falsy value.

zero-to-jupyterhub-k8s/jupyterhub/values.yaml

Line 400 in 56aeae2

cmd: jupyterhub-singleuser

[AdrianSanchezLopez]

Hi, thank you very much for your answer, problem found and solved!
I did changed the singleuser.image and updated it, but it wasn't a dockerfile based on the latest 'jupyter/base-notebook' compatible with hub:3.0.0. Now with the updated singleuser image everything works as expected.
Thanks for the quick response!