Support updating primary labels/annotations after first time rollout

[kh34]

Describe the feature

Hi, I was wondering if the ability to set primary labels/annotations as per this comment was implemented, and if not, would you accept a PR to add it?

I see it’s possible to set labels/annotations on the primary Service kinds but I don’t see a way to do this on a primary Deployment.metatdata.labels/annotations or HorizontalPodAutoscaler.metatdata.labels/annotations

This is a problem because we have governance rules for Kube object metadata, and it doesn't seem possible currently to update labels/annotations on the primary deployment/hpa if they change after the first successful canary rollout. They are correctly copied during first time deployment, but they remain static for any subsequent rollout.

Proposed solution

I want flagger to allow annotations and labels override on the primary deployment and hpa. This would be a change to the Canary Spec in a form similar to how service overrides work today:

  service:
    primary:
      annotations:
        key1: value1
      labels:
        key1: value1

For example:

  deployment:
    primary:
      annotations:
        key1: value1
      labels:
        key1: value1

  autoscaler:
    primary:
      annotations:
        key1: value1
      labels:
        key1: value1

Then it would be the responsibility of the consumer to pass along the updated map of labels/annotations to the Canary.

Any alternatives you've considered?

It would be possible to update the Promote function from e.g.

flagger/pkg/canary/deployment_controller.go

Line 83 in 01d4780

func (c *DeploymentController) Promote(cd *flaggerv1.Canary) error {

to copy the labels and annotations maps from the canary counterparts. Care might need to be taken to respect the include-label-prefix filter for labels. Currently this function only seems to copy the Pod Spec labels/annotations.

This is probably easiest from a consumer point of view since it doesn't require any changes.

Is there another way to solve this problem that isn't as good a solution?