update scaled object status with error if it's in error state about keda

[edganiukov]

In any case, if keda can't create HPA, it should report status to ScaleObject (prometheus query is invalid, some parameters are invalid, etc), otherwise there is no feedback to user (who has no access to keda logs) about status of its ScaledObject

[yaron2]

What constitutes an error state?

[ahmelsayed]

The ones I had in mind were:

• Deployment doesn't exist
• trigger connection secret doesn't exist
• bad connection to event sources (invalid connection string, password/username, not found, etc)

I think it'll make debugging issues easier if you can just lookup the status of a ScaledObject that's not behaving as you'd expect instead of going through keda logs.

[yaron2]

Yeah that makes sense, however bad connection to event sources is a pretty volatile and changing thing..

[zroubalik]

This could be reflected in Status.Conditions
https://github.com/kubernetes/community/blob/master/contributors/devel/sig-architecture/api-conventions.md#typical-status-properties

[zroubalik]

Fixed by #750