Feature request

Add SetTransform on PipelineRun and TaskRun shared informers to strip metadata.managedFields on cache insert.

Kubernetes objects carry managedFields which can be 30-70% of the object's serialized size. The Tekton controller never reads managedFields, but every DeepCopy (3-4 per reconcile cycle via the Knative reconciler framework) copies them in full.

Where to add the transform

• PipelineRun informer: pkg/reconciler/pipelinerun/controller.go (after NewImpl, before AddEventHandler)
• TaskRun informer: pkg/reconciler/taskrun/controller.go (same location)

Implementation

stripManagedFields := func(obj interface{}) (interface{}, error) {
    if accessor, ok := obj.(metav1.ObjectMetaAccessor); ok {
        accessor.GetObjectMeta().SetManagedFields(nil)
    }
    return obj, nil
}
if err := pipelineRunInformer.Informer().SetTransform(stripManagedFields); err != nil {
    logging.FromContext(ctx).Warnf("Failed to set informer transform: %v", err)
}

Use case

• Reduces memory footprint of the controller's informer caches
• Reduces CPU time spent on DeepCopy operations during reconciliation
• This pattern is established in the Kubernetes ecosystem (e.g., kube-controller-manager added ManagedFields stripping in k8s 1.27)
• SetTransform is available in client-go's shared_informer.go