Update Sensor and EventSource CRDs to support Vertical Pod Autoscaler

[fullykubed]

Is your feature request related to a problem? Please describe.

I want to use the Vertical Pod Autoscaler to automatically right-size the resource requests of pods created by the Sensor and EventSource CRs.

Describe the solution you'd like

Add scale.labelSelectorPath (docs) to CRDs to support the Vertical Pod Autoscaler's requirements when managing pods constrolled by a custom resource (docs).

Describe alternatives you've considered

None

Additional context

None

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[fullykubed]

For anyone stumbling on this with a similar goal, I was able to achieve autoscaling by augmenting the CRD manually:

apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
  name: sensors.argoproj.io
spec:
  conversion:
    strategy: None
  group: argoproj.io
  names:
    kind: Sensor
    listKind: SensorList
    plural: sensors
    shortNames:
      - sn
    singular: sensor
  scope: Namespaced
  versions:
    - name: v1alpha1
      schema:
        openAPIV3Schema:
          properties:
            apiVersion:
              type: string
            kind:
              type: string
            metadata:
              type: object
            spec:
              type: object
              x-kubernetes-preserve-unknown-fields: true
              properties:
                replicas:
                  type: number
                labelSelector:
                  type: string
            status:
              type: object
              x-kubernetes-preserve-unknown-fields: true
          required:
            - metadata
            - spec
          type: object
      served: true
      storage: true
      subresources:
        status:
          properties:
            replicas:
              type: number
        scale:
          specReplicasPath: '.spec.replicas'
          statusReplicasPath: '.status.replicas'
          labelSelectorPath: '.spec.labelSelector'

Note the addition of the spec.labelSelector field which in an ideal world would be under status.labelSelector and populated by the events controller. However, for now, you can just manually specify it on the CR and the VPA will work.