Replace deprecated base_url with bind_url

[manics]

trafficstars

Proposed change

This chart uses c.JupyterHub.base_url https://github.com/jupyterhub/zero-to-jupyterhub-k8s/blob/6f4609e2f73258c7e0146f8e849d31aa7fe7f09f/jupyterhub/files/hub/jupyterhub_config.py#L83-L94 This property was deprecated in JupyterHub 0.9 (which I've only just realised!), the replacement is c.JupyterHub.bind_url. https://github.com/jupyterhub/jupyterhub/blob/36cad38ddf00c3fe92d813fd7bf8715fb876d006/jupyterhub/app.py#L623-L633

Alternative options

Do nothing

Who would use this feature?

I think Z2JH should be an example of best practice, which means avoiding deprecated features.

(Optional): Suggest a solution

Keep the Helm chart property hub.baseUrl (since it affects components outside JupyterHub), but use it to set bind_url in jupyterhub/files/hub/jupyterhub_config.py

[consideRatio]

I'm not sure what makes sense here because I don't confidently overview the jupyterhub configuration. While base_url was a prefix only, bind_url includes more I think, and then there is hub_bind_url as well etc.

I can imagine this may requires a breaking change, so it would be great to nudge this pre-2.0.0 release.

Here are some baseUrl related logic, note that its used both by the helm chart templates, and the jupyterhub_config.py file.

https://github.com/jupyterhub/zero-to-jupyterhub-k8s/blob/31edd218ceb02d4f1220da4a6c6e41942a517926/jupyterhub/files/hub/jupyterhub_config.py#L82

https://github.com/jupyterhub/zero-to-jupyterhub-k8s/blob/31edd218ceb02d4f1220da4a6c6e41942a517926/jupyterhub/files/hub/jupyterhub_config.py#L95-L105

https://github.com/jupyterhub/zero-to-jupyterhub-k8s/blob/31edd218ceb02d4f1220da4a6c6e41942a517926/jupyterhub/files/hub/jupyterhub_config.py#L354-L356

https://github.com/jupyterhub/zero-to-jupyterhub-k8s/blob/31edd218ceb02d4f1220da4a6c6e41942a517926/jupyterhub/schema.yaml#L413-L418

https://github.com/jupyterhub/zero-to-jupyterhub-k8s/blob/31edd218ceb02d4f1220da4a6c6e41942a517926/jupyterhub/templates/ingress.yaml#L20

[manics]

https://github.com/jupyterhub/jupyterhub/pull/4564