plugin for creating environmental variables

[raybellwaves]

I would like a plugin function to create environmental variables.

Motivation is for dask/dask-labextension#183 i.e. set
export DASK_DISTRIBUTED__DASHBOARD__LINK=/user/${JUPYTERHUB_USER}/proxy/8787/status

Proposed change

A function in https://github.com/jupyterhub/the-littlest-jupyterhub/blob/main/tljh/hooks.py called tljh_environmnetal_variables'

Alternative options

Maybe this can be done currently with https://github.com/jupyterhub/the-littlest-jupyterhub/blob/main/tljh/hooks.py#L69 but not sure how

os.environ["DASK_DISTRIBUTED__DASHBOARD__LINK"] = f"user/{os.getenv('JUPYTERHUB_USER')}/proxy/8787/status"

Not sure if it will persist though

Who would use this feature?

People who want to use the dask lab extension

(Optional): Suggest a solution

[raybellwaves]

Some work here

https://github.com/jupyterhub/the-littlest-jupyterhub/pull/414/files

If that goes could make that conf file plugable?

[raybellwaves]

Done via yaml in z2jh https://zero-to-jupyterhub.readthedocs.io/en/latest/jupyterhub/customizing/user-environment.html#set-environment-variables