✨ [#1617] added feature to see if connection is alive in ser…

[bart-maykin]

…vice admin list page

Fixes #1617
Fixes some aspects of #12

Added health_check read_only_field in the service admin panel

[sergei-maertens]

I'll review this tomorrow

[sergei-maertens]

First of all - this implementation is not according to the specification in the ticket:

I'd like to have a 'Check configuration' button in the Service detailview that performs a GET request to the API root URL with the authentication-options configured and shows the response.

The way this PR implements it, causes this check request to be made every time you open the detail view/edit form of a service (and I'm also not sure how this behaves when you are adding new objects rather than editing an existing one).

This is the opposite of performing an explicit check after clicking a button. So please change the UX/UI by displaying a button or link to test the connection, which takes you to a custom admin view. In this admin view, I expect a form with the following fields:

• Method (GET / POST), default to GET
• Endpoint to test (forms.CharField). It's okay to add a model field health_check_path like you did. This path needs to be appended to the api_root, so it cannot be absolute.

A button to submit the form, and on submissions, the health check is performed and the result reported back.

The reason for this is:

• performance - you don't want to spam the remote service every time you are editing the configuration
• a service may not be reachable with GET methods only, e.g. a SOAP endpoint typically only allows POST requests
• Diagnosing a service may require the user to try different endpoints, so having a health check path as default is fine, but it should be possible to override this at check-time

An finally, model tests alone are not sufficient. You are modifying admin behaviour, so this needs client/view tests too to ensure nothing has broken and the feature is working as intended.

[joeribekker]

Refinement: Bart and I discussed and the way its implemented matches what we discussed (but I didnt wrote it down as such afterwards). All technical issue can be addressed and or answered @bart-maykin.

We can rename it to "connection check" or whatever. This is an admin perspective on whether we can connect to an endpoint and not so much a healthcheck (but named so because Bart thought Sergei wanted this).

[joeribekker]

Return status code please instead of boolean.

[SonnyBA]

One question regarding performing the actual request but overall looks good to me 👍

[sergei-maertens]

nitpicking 😬