Add support to customize HPA name

[aviadlevy]

Proposal

Add new field to allow custom hpa name (and not just keda-hpa-<name>)

Use-Case

For example:

apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  annotations:
    ...
  labels:
    ...
  name: ...
spec:
  advanced:
    horizontalPodAutoscalerConfig:
      hpaName: my-prsonal-hpa-name

Then keda will generate hpa named my-prsonal-hpa-name

Anything else?

If you're thinking it's a good proposal, I would like to try implement it myself and open PR 🙏

[tomkerkhove]

Fair ask, I like it.

I would, however, suggest to do the following as we try to avoid using abbreviations and it's already in horizontalPodAutoscalerConfig

apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  annotations:
    ...
  labels:
    ...
  name: ...
spec:
  advanced:
    horizontalPodAutoscalerConfig:
-      hpaName: my-prsonal-hpa-name
+      name: my-prsonal-hpa-name

[JorTurFer]

I like the idea, I'm afraid about the implementation. I mean, right now it's easy to manage the resources (in k8s) created by KEDA because are deterministic in the names and they don't change,
if we proceed with this feature, we should ensure that we manage the resources properly in all edge cases like if we modify the custom name in the SO with the operator down. I mean, the old HPA has to be removed and then create the new one, otherwise we will have 2 HPA. It's not a problem IMO, but we must should it

[aviadlevy]

I like the idea, I'm afraid about the implementation. I mean, right now it's easy to manage the resources (in k8s) created by KEDA because are deterministic in the names and they don't change, if we proceed with this feature, we should ensure that we manage the resources properly in all edge cases like if we modify the custom name in the SO with the operator down. I mean, the old HPA has to be removed and then create the new one, otherwise we will have 2 HPA. It's not a problem IMO, but we must should it

Yep, saw that while I start browsing the code. Do you have any suggestion how to know that we changed the hpa name and we need to clean the "old" one?
One idea I had is to use an annotation with fixed name (like "app.kubernetes.io/part-of": scaledObject.Name,) and search for it. what do you say?

[JorTurFer]

Maybe we could add the "currently created" hpa's name in the SO status 🤔
WDYT @zroubalik ?

[zroubalik]

Yeah, SO.Status is the only field where we can imho save it.

I think that if we are going to implement this change, a solid test coverage needs to be done.

[JorTurFer]

I think that if we are going to implement this change, a solid test coverage needs to be done.

Agree

[aviadlevy]

Sounds good.
Can I still get a chance to try do it myself (though golang is not my primary language)?
If I'll see it's too much for me, I'll let you know

[zroubalik]

@aviadlevy definitely! :)