Write proposal for merging binderhub helm-chart (only) into zero to jupyterhub helm chart

[yuvipanda]

Part of

Remove artificial distinctions between BinderHub/JupyterHub. Currently BinderHub and JupyterHub have strong distinctions between them, but this is not strictly necessary. Binder-like functionality should be a feature flag on any JupyterHub, and thus BinderHub could cease to be a standalone tool, and instead be a “particular configuration of a JupyterHub”.

From https://discourse.pangeo.io/t/notes-from-the-pangeo-2i2c-kick-off-meeting/1587

Implementation details

We want to make sure that others in the community have buy-in for this idea, but it's hard to know exactly what steps would be needed for feedback.

Here is roughly what we want to try:

• Build a prototype that others can comment on
• Make a proposal that lays out the idea, benefit, and implementation (maybe just pointing to the prototype for what implementation would look like)
• Discuss w/ the team and get a decision how to move forward

Updates

• [ ] 2021-09-21 @yuvipanda is going to try and get together a prototype that shows off image building from within a JupyterHub. It's not clear how long this will take, but our goal for this sprint is to explore what this would look like. We'll re-assess next week when we understand more.

[choldgraf]

In a sprint meeting we discussed that this effort is challenging because there are several moving parts, and it's unclear what is the best path to get buy-in from the broader JupyterHub team. We decided that a good next step would be to build a working prototype that shows off image building in JupyterHub deployed as a service via a combined helm chart, to have something specific that we can point to as a benefit, and to help shape discussion with the team. So the order of operations is roughly:

• Build a prototype that others can comment on
• Make a proposal that lays out the idea, benefit, and implementation (maybe just pointing to the prototype for what implementation would look like)
• Discuss w/ the team and get a decision how to move forward

@yuvipanda let me know if any of that looks incorrect