IllegalStateException thrown when deleting a resource observed by a Reconciler

[silenium-dev]

Bug Report

What did you do?

I created a basic reconciler for a cluster-scoped custom resource:

class ProjectReconciler : Reconciler<Project> {
    override fun reconcile(
        resource: Project,
        context: Context<Project>,
    ): UpdateControl<Project> {
        println("Reconciling ${resource.metadata.name}")

        if (resource.status == null) {
            resource.status = ProjectStatus()
        }

        return UpdateControl.patchStatus(resource)
    }
}

I've then started the operator, created the custom resource and then deleted it.

What did you expect to see?

It doesn't throw an exception when I delete it.

What did you see instead? Under which circumstances?

When I delete the custom resource, the operator throws the following exception:

java.lang.IllegalStateException: Should not be called with DELETED
	at io.javaoperatorsdk.operator.processing.event.source.controller.ControllerResourceEventSource.isAcceptedByFilters(ControllerResourceEventSource.java:98)
	at io.javaoperatorsdk.operator.processing.event.source.controller.ControllerResourceEventSource.eventReceived(ControllerResourceEventSource.java:75)
	at io.javaoperatorsdk.operator.processing.event.source.controller.ControllerResourceEventSource.onDelete(ControllerResourceEventSource.java:118)
	at io.javaoperatorsdk.operator.processing.event.source.controller.ControllerResourceEventSource.onDelete(ControllerResourceEventSource.java:28)
	at io.fabric8.kubernetes.client.informers.impl.cache.ProcessorListener$DeleteNotification.handle(ProcessorListener.java:122)
	at io.fabric8.kubernetes.client.informers.impl.cache.ProcessorListener.add(ProcessorListener.java:50)
	at io.fabric8.kubernetes.client.informers.impl.cache.SharedProcessor.lambda$distribute$0(SharedProcessor.java:87)
	at io.fabric8.kubernetes.client.informers.impl.cache.SharedProcessor.lambda$distribute$1(SharedProcessor.java:110)
	at io.fabric8.kubernetes.client.utils.internal.SerialExecutor.lambda$execute$0(SerialExecutor.java:58)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base/java.lang.Thread.run(Thread.java:833)

Environment

Kubernetes cluster type: minikube

$ Mention java-operator-sdk version from pom.xml file

java-operator-sdk version: 4.2.0

$ java -version

openjdk version "17.0.5" 2022-10-18
OpenJDK Runtime Environment GraalVM CE 22.3.0 (build 17.0.5+8-jvmci-22.3-b08)
OpenJDK 64-Bit Server VM GraalVM CE 22.3.0 (build 17.0.5+8-jvmci-22.3-b08, mixed mode, sharing)

$ kubectl version

Client Version: version.Info{Major:"1", Minor:"24", GitVersion:"v1.24.4", GitCommit:"95ee5ab382d64cfe6c28967f36b53970b8374491", GitTreeState:"clean", BuildDate:"2022-08-17T18:54:23Z", GoVersion:"go1.18.5", Compiler:"gc", Platform:"linux/amd64"}
Kustomize Version: v4.5.4
Server Version: version.Info{Major:"1", Minor:"25", GitVersion:"v1.25.3", GitCommit:"434bfd82814af038ad94d62ebe59b133fcb50506", GitTreeState:"clean", BuildDate:"2022-10-12T10:49:09Z", GoVersion:"go1.19.2", Compiler:"gc", Platform:"linux/amd64"}

Possible Solution

ControllerResourceEventSource contains a method isAcceptedByFilters():

private boolean isAcceptedByFilters(ResourceAction action, T resource, T oldResource) {
  // delete event is filtered for generic filter only.
  if (genericFilter != null && !genericFilter.accept(resource)) {
    return false;
  }
  switch (action) {
    case ADDED:
      return onAddFilter == null || onAddFilter.accept(resource);
    case UPDATED:
      return onUpdateFilter.accept(resource, oldResource);
    case DELETED:
      throw new IllegalStateException("Should not be called with " + action);
  }
  return true;
}

For some reason, it throws an exception if it's called for deletions, even though there is a comment that says it only uses the generic filters for deletions. This was changed in commit 952a26b. It just returned true before.
A possible fix would be removing the DELETE case and adding a default case which returns true.

Additional context

I'm using the Quarkiverse Operator SDK extension for Quarkus.

[csviri]

Hi there is already a PR for this to fix, will do soon and release a patch version. Thx for reporting.

[csviri]

see: #1679