Implement Kubernetes Event API v1

Transition the Flux ecosystem from legacy core/v1 events to the modern events.k8s.io/v1 API. The following changes have to follow a backward compatibility approach where legacy fields may be bridged to the new schema (e.g., keep InvolvedObject regardless of being renamed, add a new RelatedObject field) to ensure no breaking changes for users relying on current event logs.

Action Items

• Add a new AnnotatedEventRecorder interface upstream in client-go/tools/events - kubernetes/kubernetes#138103
• Controller-Runtime - kubernetes-sigs/controller-runtime#3509
• Update fluxcd/pkg to use events.k8s.io/v1 - fluxcd/pkg#1144
• Update all controllers using the changes done in runtime/events from fluxcd/pkg. Use new field relatedObject to include object's source metadata (as InvolvedObject does) and Action as mandatory field.
  • Mandatory controllers
    • Notification-Controller - fluxcd/notification-controller#1267
      • Adapt the event receiver to handle the events.k8s.io/v1 schema.
      • Update spec/v1beta3/events.md to document new fields.
    • Helm-Controller fluxcd/helm-controller#1510
    • Kustomize-Controller fluxcd/kustomize-controller#1621
    • Source-Controller fluxcd/source-controller#2011
  • Optional controllers
    • Source-Watcher fluxcd/source-watcher/pull/343
    • Image-Automation-Controller fluxcd/image-automation-controller#1038
    • Image-Reflector-Controller fluxcd/image-reflector-controller#889

Reference to the new API spec and changes

• API Deprecation Guide ( events.k8s.io/v1beta1 deprecated since k8s 1.25)
• KEP-383: New Event API GA Graduation