Add support for HPA and Keda autoscaling

[xoanmi]

We are adding support for autoscale deployments with Horizontal Pod Autoscaling (HPA) and Keda.

This change is backward compatible since it adds new functionalities. With the default values the new settings have no effect.

Out of scope:

• database: replicas is hardcoded to 1
• redis: replicas is hardcoded to 1

close #1068

[xoanmi]

@zyyw @Vad1mo could you please take a look to this PR?

[Vad1mo]

I am not sure if that isn't a bit too much for Harbor. HPA I can understand, but Keda. Any chance we can have it on the side/extension and not part of the main Helm chart?

[xoanmi]

I am not sure if that isn't a bit too much for Harbor. HPA I can understand, but Keda. Any chance we can have it on the side/extension and not part of the main Helm chart?

We would love to have Keda also supported to be able to scale the jobService based on the number of jobs in queue. IMHO is the same use case than the HPA but just with a different operator.

The problem with having it as a side extension is that we need to remove the ‘replicas’ object from the deployment. TBH I don't know how to do it without integrating it in the same chart… 😥

However, if you don't feel comfortable with that I can split the change into two different PRs so we could proceed with the HPA right away and proper discuss how to support Keda.

[zyyw]

This seems a little bit too much for goharbor/harbor-helm.

[xoanmi]

I have opened a new PR that adds support exclusively for HPA (#1765). I hope this aligns more closely with the project's scope.