Avoid requiring jupyter_config.py in to be in uiserver subdirectory

[wxtim]

Closes #565

Previously it was assumed to be in CYLC_SITE_CONF_PATH/uiserver.

Ensure that user is warned if file at CYLC_SITE_CONF_PATH is

• Unreadable
• Non-existent

Check List

• I have read CONTRIBUTING.md and added my name as a Code Contributor.
• Contains logically grouped changes (else tidy your branch by rebase).
• Does not contain off-topic changes (use other PRs for other changes).
• Applied any dependency changes to both setup.cfg (and conda-environment.yml if present).
• Tests are included (or explain why tests are not needed).
• CHANGES.md entry included if this is a change that can affect users
• Cylc-Doc pull request opened if required at cylc/cylc-doc/pull/XXXX.
• If this is a bug fix, PR should be raised against the relevant ?.?.x branch.

[oliver-sanders]

Previously it was assumed to be in CYLC_SITE_CONF_PATH/uiserver.

This was correct and consistent with cylc-flow which looks in $CYLC_SITE_CONF_PATH/flow.

The CYLC_SITE_CONF_PATH directory is supposed to look like this:

.
|-- flow
|   `-- global.cylc
`-- uiserver
    `-- jupyter_config.py

The intention is that it can be used to configure all of the Cylc components.

As of the current versions setting CYLC_SITE_CONF_PATH to the root of the above structure works fine for me.

[wxtim]

As of the current versions setting CYLC_SITE_CONF_PATH to the root of the above structure works fine for me.

So this can be closed?

[oliver-sanders]

Check the issue.

[oliver-sanders]

Had a read through the issue, I think these are the main points:

1. The config file didn't get picked up in the location the docs suggested.
   • Check the current behaviour (i.e. $CYLC_SITE_CONF_DIR/uiserver/jupyter_config.py) makes sense and is consistent with cylc-flow.
   • If so, amend the docs as needed.
2. If the config file is not readable, there is no error.
   • This is likely Jupyter Server behaviour (try reproducing this using jupyter server).
   • If this is special Cylc behaviour, not Jupyter Server behaviour, then it's a bug.
   • Otherwise, we could consider pushing an upstream change to Jupyter Server.
3. If no config files are found / readable, they would like a warning stating that users have no access.
   • I'm not sure I get this bit.

[wxtim]

Had a read through the issue, I think these are the main points:

Sorry, so have I, just not been high enough on my todo-list. It is on my radar.

[wxtim]

The config file didn't get picked up in the location the docs suggested.

This works as documented here, although there might be a case for an extra note on the uiserver app docs.

[wxtim]

@oliver-sanders - I'm not convinced that this PR is necessary.

[hjoliver]

Can we close this then?