Add ability to define and run a subset health checks

[panteparak]

This PR Introduces an ability to define and run a SUBSET of health checks.

It will be useful during certain period where it is only required to run specific health checks during a scenario.

It supports both via url /ht/<subset-name>/ and via Django command python manage.py health_check --subset <subset-name>

[panteparak]

Hi @codingjoe

Just a polite ping!.

Could I have some feedback on this PR.

Really love to see this feature in the official release of django-health-check.

[frankwiles]

This looks great @panteparak I think it's definitely worth including. I'm hoping to do another release in the next few days (was actually supposed to do it last weekend but something came up) so I can include this in there.

[panteparak]

@frankwiles Just a friendly reminder: Don't forget to create a new release :)

[saz]

@frankwiles FYI: this is a breaking change, if you've got custom checks, as the signature of BaseHealthCheckBackend.check_status has changed.

TypeError: CeleryBeatCheckBackend.check_status() got an unexpected keyword argument 'subset'

I'll send a PR to fix the docs. Maybe it's possible to add some hint to the current release notes?

[SpecLad]

It's not clear to me what the point of the subset parameter even is. None of the builtin health check backends actually use it. Can't it be removed to restore compatibility?

[ramwin]

@frankwiles FYI: this is a breaking change, if you've got custom checks, as the signature of BaseHealthCheckBackend.check_status has changed.

TypeError: CeleryBeatCheckBackend.check_status() got an unexpected keyword argument 'subset'

I'll send a PR to fix the docs. Maybe it's possible to add some hint to the current release notes?

I agree with you, this merge request should be merged into 4.0.0 only.

[saz]

@SpecLad There's an example usage in the README (not within the docs).

[SpecLad]

@SpecLad There's an example usage in the README (not within the docs).

Where? The README hasn't even been updated to include the subset parameter.

[saz]

Can't link to the proper section, but as said, it's only in the README, not the documentation.

[SpecLad]

This doesn't describe the subset parameter.

[saz]

Ah, sorry, misunderstanding on my side. It looks like as if the subset parameter on check_status isn't used anywhere.

@panteparak Can you shed some light on this?

[llam15]

I would like to +1 that this is a breaking change and should not have been released as a minor version update. This caused all of our custom health checks to fail with a TypeError

...check_status() got an unexpected keyword argument 'subset'

The minor version upgrade from 3.17 to 3.18 was pulled automatically because we had specified our dependency django-health-check = "^3.16", and unexpectedly caused the health checks to stop working.

---

For others: we were able to fix our custom health checks by modifying the check_status definition as so:

def check_status(self, *args, **kwargs):

[SpecLad]

I made a PR to unbreak this: #414.