conda: document environment files

[oliver-sanders]

We should document some example Cylc stack installations in the form of Conda environment files.

See cylc/cylc-admin#130

As an added bonus we could build these environments as part of the test battery to make sure they don't break.

[wxtim]

I'm going to aim to add the following:

• A most-basic environment, containing cylc-flow its dependencies
• A "vanilla" environment, containing cylc-flow, cylc-uiserver and possibly cylc-ui (unsure how yarn and conda interact)
• A cylc-rose environment, cylc, cylc-rose and rose

[oliver-sanders]

We should include details/examples of the following options:

• Python (setting version number).
• JupyterHub (now optional via pip, soon to be a separate output on conda).
• Configurable HTTP Proxy (optional for JupyterHub via conda, alternatives exist).
• Jupyter Lab.
• Jupyter Lab / Hub plugins.
• Rose / Cylc Rose.

[wxtim]

* Python (setting version number).

Easy to add. Will do.

* JupyterHub (now optional via pip, soon to be a separate output on conda).

* Configurable HTTP Proxy (optional for JupyterHub via conda, alternatives exist).

* Jupyter Lab.

* Jupyter Lab / Hub plugins.

I don't know very much about these things. Will @datamel be able to fill me in?

* Rose / Cylc Rose.

Done this

[oliver-sanders]

I'll try to take a stab at the JupyterHub and Configurable HTTP Proxy stuff when we make the next release (can't really document right now as we haven't sorted it out yet, just jotting it down so we don't forget).

The Lab stuff is literally just adding jupyterlab into the Conda deps list (no version required).

We could document a couple of the most useful plugins, the SSH authenticator will likely be essential for a few setups. We will provide our own SSH spawner though.

[wxtim]

O.K. I'll add the differing python versions and JupyterLab and flesh out the docs a little by adding the commands used to create the nvs then leave the rest for now.

[wxtim]

@oliver-sanders - did #293 add enough that you'd close the issue?

[oliver-sanders]

Not yet, still need to cover the hub, configurable-http-proxy, etc, see above comments.

Will do after the next uis release (as that will change installation instructions), we haven't got a conda-forge PR up to handle the change yet.

[oliver-sanders]

Closed by #342