controller-runtime WithEventFilt

// Setup adds a controller that schedules KubernetesApplications.
func Setup(mgr ctrl.Manager, l logging.Logger) error {
    name := "scheduler/" + strings.ToLower(workloadv1alpha1.KubernetesApplicationGroupKind)

    return ctrl.NewControllerManagedBy(mgr).
        Named(name).
        For(&workloadv1alpha1.KubernetesApplication{}).
        WithEventFilter(&predicate.Funcs{CreateFunc: CreatePredicate, UpdateFunc: UpdatePredicate}).
        Complete(&Reconciler{
            kube:      mgr.GetClient(),
            scheduler: &roundRobinScheduler{kube: mgr.GetClient()},
            log:       l.WithValues("controller", name),
        })
}

// Funcs is a function that implements Predicate.
type Funcs struct {
    // Create returns true if the Create event should be processed
    CreateFunc func(event.CreateEvent) bool

    // Delete returns true if the Delete event should be processed
    DeleteFunc func(event.DeleteEvent) bool

    // Update returns true if the Update event should be processed
    UpdateFunc func(event.UpdateEvent) bool

    // Generic returns true if the Generic event should be processed
    GenericFunc func(event.GenericEvent) bool
}