Cannot record events outside reconciliation loop or for arbitrary resources (RegisteredController#eventRecorder missing) #3686

Bug Report

What did you do?

We attempted to record a Kubernetes event for our primary/main resource from within the reconciliation loop of a sub-resource / secondary controller, following the v5.6 release notes:
https://javaoperatorsdk.io/blog/2026/09/02/version-5.6-released/#kubernetes-event-recorder

According to the release documentation:

"Outside of the reconciliation loop — from a status listener or a background task, or about an object other than the primary — use the unbound form from RegisteredController#eventRecorder(), which is scoped to the controller rather than to a reconciliation:

EventRecorder recorder = registeredController.eventRecorder();
recorder.record(someOtherResource, EventRecord.normal("Noticed", "something happened"));

What did you expect to see?

1. RegisteredController exposes an eventRecorder() method (or equivalent API) to obtain an unbound EventRecorder.
2. EventRecorder provides a way to record events for an arbitrary target resource (e.g. recorder.record(someOtherResource, EventRecord.normal(...))), allowing a controller reconciling a sub-resource to emit an event on its main/parent resource.

What did you see instead? Under which circumstances?

1. RegisteredController does not contain eventRecorder(). Calling registeredController.eventRecorder() fails to compile.
2. In Context<P>, eventRecorder() returns a ResourceEventRecorder strictly bound to context.getPrimaryResource().
3. In DefaultEventRecorder, toEvent(...) hardcodes the target resource to context.getPrimaryResource():

   var regarding = context.getPrimaryResource();
   and EventRecorder#record only accepts (EventRecord event, Context<?> context).

As a result, when reconciling a sub-resource (where context.getPrimaryResource() is the sub-resource), there is no supported way to publish an event targeting the main/parent resource.

Environment

Kubernetes cluster type: any
java-operator-sdk version: 5.6.3
java -version: 17 / 21
kubectl version: 1.30+

Possible Solution

Tracing through the PR history:

• PR feat: Add Event Recorder #3570 (feat: Add Event Recorder) originally introduced RegisteredController#eventRecorder() and supported recording events for arbitrary objects.
• PR refactor: configurable event recorder #3581 (refactor: configurable event recorder) refactored the API to be stateless and removed RegisteredController#eventRecorder(), inadvertently dropping the ability to record events outside a reconciliation context or targeting a resource other than context.getPrimaryResource().
  Suggested fixes:

1. Re-introduce an unbound EventRecorder accessible via RegisteredController, ConfigurationService, or Operator.
2. Allow passing an explicit target HasMetadata targetResource (or via EventRecord / EventRecorder#record(targetResource, ...)), rather than exclusively binding to context.getPrimaryResource().

Additional context

Our use case: We have separate controllers reconciling sub-resources. When state changes or failures occur during the reconciliation of a sub-resource, we need to publish a Kubernetes event targeting the main/parent resource so users inspecting the parent resource (kubectl describe ) have visibility into events triggered by its sub-resources.