[Bug] KubeApiDiscovery Failed to synchronize Endpoints in namespace default

[zerda]

Current Behavior

When deployed with helm chart in namespace default, Pod cryostat-v4 logs print Failed to syncronize Endpoints in namespace default error message.

2025-05-09 16:46:52,475 ERROR [io.cry.dis.KubeApiDiscovery] (executor-thread-1) Failed to syncronize Endpoints in namespace default: java.lang.NullPointerException: Cannot invoke "io.fabric8.kubernetes.api.model.ObjectReference.getNamespace()" because "ref" is null
	at io.cryostat.discovery.KubeApiDiscovery.tuplesFromEndpoints(KubeApiDiscovery.java:232)
	at io.cryostat.discovery.KubeApiDiscovery.getTargetTuplesFrom(KubeApiDiscovery.java:243)
	at io.cryostat.discovery.KubeApiDiscovery.lambda$handleQueryEvent$4(KubeApiDiscovery.java:300)
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
	at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1708)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
	at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682)
	at io.cryostat.discovery.KubeApiDiscovery.handleQueryEvent(KubeApiDiscovery.java:312)
	at io.cryostat.discovery.KubeApiDiscovery_Subclass.handleQueryEvent$$superforward(Unknown Source)
	at io.cryostat.discovery.KubeApiDiscovery_Subclass$$function$$2.apply(Unknown Source)
	at io.quarkus.arc.impl.AroundInvokeInvocationContext.proceed(AroundInvokeInvocationContext.java:73)
	at io.quarkus.arc.impl.AroundInvokeInvocationContext.proceed(AroundInvokeInvocationContext.java:62)
	at io.quarkus.narayana.jta.runtime.interceptor.TransactionalInterceptorBase.invokeInOurTx(TransactionalInterceptorBase.java:136)
	at io.quarkus.narayana.jta.runtime.interceptor.TransactionalInterceptorBase.invokeInOurTx(TransactionalInterceptorBase.java:107)
	at io.quarkus.narayana.jta.runtime.interceptor.TransactionalInterceptorRequiresNew.doIntercept(TransactionalInterceptorRequiresNew.java:41)
	at io.quarkus.narayana.jta.runtime.interceptor.TransactionalInterceptorBase.intercept(TransactionalInterceptorBase.java:61)
	at io.quarkus.narayana.jta.runtime.interceptor.TransactionalInterceptorRequiresNew.intercept(TransactionalInterceptorRequiresNew.java:32)
	at io.quarkus.narayana.jta.runtime.interceptor.TransactionalInterceptorRequiresNew_Bean.intercept(Unknown Source)
	at io.quarkus.arc.impl.InterceptorInvocation.invoke(InterceptorInvocation.java:42)
	at io.quarkus.arc.impl.AroundInvokeInvocationContext.perform(AroundInvokeInvocationContext.java:30)
	at io.quarkus.arc.impl.InvocationContexts.performAroundInvoke(InvocationContexts.java:27)
	at io.cryostat.discovery.KubeApiDiscovery_Subclass.handleQueryEvent(Unknown Source)
	at io.cryostat.discovery.KubeApiDiscovery_ClientProxy.handleQueryEvent(Unknown Source)
	at io.cryostat.discovery.KubeApiDiscovery_handleQueryEvent_Invoker_-8wgLqvC_-i4engVkpoKZrK1uko.invoke(Unknown Source)
	at io.cryostat.discovery.KubeApiDiscovery_handleQueryEvent_LazyInvoker_-8wgLqvC_-i4engVkpoKZrK1uko.invoke(Unknown Source)
	at io.quarkus.vertx.runtime.EventConsumerInvoker.invokeBean(EventConsumerInvoker.java:79)
	at io.quarkus.vertx.runtime.EventConsumerInvoker.invoke(EventConsumerInvoker.java:51)
	at io.quarkus.vertx.runtime.VertxEventBusConsumerRecorder$3$1$2.call(VertxEventBusConsumerRecorder.java:158)
	at io.quarkus.vertx.runtime.VertxEventBusConsumerRecorder$3$1$2.call(VertxEventBusConsumerRecorder.java:154)
	at io.vertx.core.impl.ContextImpl.lambda$executeBlocking$4(ContextImpl.java:192)
	at io.vertx.core.impl.ContextInternal.dispatch(ContextInternal.java:270)
	at io.vertx.core.impl.ContextImpl$1.execute(ContextImpl.java:221)
	at io.vertx.core.impl.WorkerTask.run(WorkerTask.java:56)
	at io.vertx.core.impl.TaskQueue.run(TaskQueue.java:81)
	at io.quarkus.vertx.core.runtime.VertxCoreRecorder$14.runWith(VertxCoreRecorder.java:635)
	at org.jboss.threads.EnhancedQueueExecutor$Task.doRunWith(EnhancedQueueExecutor.java:2516)
	at org.jboss.threads.EnhancedQueueExecutor$Task.run(EnhancedQueueExecutor.java:2495)
	at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1521)
	at org.jboss.threads.DelegatingRunnable.run(DelegatingRunnable.java:11)
	at org.jboss.threads.ThreadLocalResettingRunnable.run(ThreadLocalResettingRunnable.java:11)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Thread.java:1583)

Expected Behavior

kube-api discovery should be working in namespace default, with builtin name=kubernetes service.

Steps To Reproduce

1. helm install cryostat cryostat-charts/cryostat;
2. kubectl logs cryostat-v4-5df98d8c48-9c9jg;

Environment

- OS: macOS 15.3.2
- Environment: OrbStack 1.10.3
- Version: Cryostat 4.0.0

Anything else?

this kubernetes service in default namespace has no selector, so the endpoint is not ref to any pod.

apiVersion: v1
kind: Endpoints
metadata:
  creationTimestamp: "2024-11-14T23:05:38Z"
  labels:
    endpointslice.kubernetes.io/skip-mirror: "true"
  name: kubernetes
  namespace: default
  resourceVersion: "72"
  uid: 3f90a71d-3843-4a13-ba40-9bf1d274c8b2
subsets:
- addresses:
  - ip: 198.19.249.2
  ports:
  - name: https
    port: 26443
    protocol: TCP

not like other service, for example

apiVersion: v1
kind: Endpoints
metadata:
  annotations:
    endpoints.kubernetes.io/last-change-trigger-time: "2025-05-09T18:11:56Z"
  creationTimestamp: "2025-05-09T17:36:16Z"
  labels:
    app.kubernetes.io/component: cryostat
    app.kubernetes.io/instance: cryostat
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/name: cryostat
    app.kubernetes.io/part-of: cryostat
    app.kubernetes.io/version: 4.0.0
    helm.sh/chart: cryostat-2.0.0
  name: cryostat
  namespace: default
  resourceVersion: "36099"
  uid: 71457534-39fc-46c2-981b-450d8e02f4e5
subsets:
- addresses:
  - ip: 192.168.194.46
    nodeName: orbstack
    targetRef:
      kind: Pod
      name: cryostat-v4-5df98d8c48-9c9jg
      namespace: default
      uid: 40531965-e0c5-45a3-85f0-35f46422c7d1
  ports:
  - appProtocol: http
    name: http
    port: 4180
    protocol: TCP

[andrewazores]

Related: #740 . I think I might already have a fix in there, if not I can include one.