Do not hard-code the deployment form URL

[krassowski]

Context

The form URL is currently hard-coded in:

jupyterlab-jhub-apps/src/index.ts

Lines 54 to 58 in 0e0faf6

	if (currentNotebookPath !== '') {
	deployUrl = `/services/japps/create-app?filepath=${encodeURIComponent(currentNotebookPath)}`;
	} else {
	deployUrl = '/services/japps/create-app';
	}

Value and/or benefit

To alleviate the concerns about potentially blocking releases when jhub-apps changes its routes, we could instead establish a contract with jhub-apps that it populates the form URL in pageConfig or in the settings with URL that this extension then reads.

For context, JupyterHub itself adds to pageConfig here - this hook would need to be extended on the jhub-apps side if we go with page config approach. Then this extension would read it like this:

import { PageConfig } from '@jupyterlab/coreutils';
// ...
PageConfig.getOption('deploymentFormUrl')

Alternatively we could:

• use JSON settings and populate them in nebari (not so great as it couples it with nebari!)
• add a configuration URL endpoint in jhub-apps that shares mapping to public API URLs (this feels like an overkill)

Or:

• we could decide that this URL is safe enough and jhub-apps could mark it as a stable API (which will only change with enough heads up to adopt this extension),
• we could merge this repo into jhub-apps repo to develop in a monorepo
  • that would be potentially harder to maintain as copier allows us to keep this repo in sync with the template easier when it is standalone

Anything else?

CC @aktech

[krassowski]

Closing as solved in #12