ManagedKubernetesClient configuration policy should be REQUIRE

[mattrpav]

Describe the bug

ManagedKubernetesClient does not handle activate( ) method being called with null properties. The Configuration policy should be set to 'REQUIRE' in order to only activate when a config is present.

Fabric8 Kubernetes Client version

5.5.0

Steps to reproduce

1. Deploy kubernetes-client in osgi w/o a config file
2. Observe NPE

Caused by: java.lang.NullPointerException
	at io.fabric8.kubernetes.client.osgi.ManagedKubernetesClient.activate(ManagedKubernetesClient.java:143) ~[kubernetes-client-5.3.1-bundle.jar:?]
	... 73 more

Expected behavior

Do not try to activate a ManagedKubernetesClient without a configuration file

Runtime

Kubernetes (vanilla)

Kubernetes API Server version

1.20.12

Environment

macOS

Fabric8 Kubernetes Client Logs

No response

Additional context

No response

[rohanKanojia]

@mattrpav : I have a question in the context of #3864 . Do you have some reproducer project which I can try out and reproduce for ManagedOpenShiftClient?

[rohanKanojia]

@mattrpav : I wanted to ask another question, Have you upgraded to Fabric8 Kubernetes Client 6.x version and checked whether this fix is working for you?

I'm trying to prepare a reproducer for #3864 but at the moment I'm getting this exception with ManagedKubernetesClient:

llPointerException - null]
[INFO] k8s: java.lang.NullPointerException: null
[INFO] k8s: 	at io.fabric8.kubernetes.client.osgi.NamespacedKubernetesClientAdapter.getClient(NamespacedKubernetesClientAdapter.java:120) ~[!/:?]
[INFO] k8s: 	at io.fabric8.kubernetes.client.osgi.NamespacedKubernetesClientAdapter.resources(NamespacedKubernetesClientAdapter.java:131) ~[!/:?]

I'm not sure whether I'm using ManagedKubernetesClient correctly or not. Could you please review my reproducer and provide some feedback ?

[mattrpav]

@rohanKanojia I don't use OpenShift, so not sure how it'll behave.

I'm happy to test out 6.x-- it'll be a bit later this week. I've got 3 other oss fixes in the queue.

[rohanKanojia]

@mattrpav : You don't have to worry about OpenShift. I will fix that as part of #3864

My question is regarding your OSGI project setup in ManagedKubernetesClient (any rough code snippet would be super helpful). I can replicate that onto OpenShift. Could you please review my reproducer to see if's trying to reproduce correctly https://github.com/rohankanojia-forks/kubernetes-client-osgi-demo/blob/main/src/main/java/org/eclipse/jkube/quickstart/karaf/K8sBookGenerator.java#L42?

[rohanKanojia]

@mattrpav : May I ask which OSGi framework are you using? I'm trying Apache Karaf. I'm trying to add ManagedKuberntesClient via org.osgi.service.component.annotations.Reference

  @Reference
  ManagedKubernetesClient kubernetesClient;

I've provided it in OSGI-INF/blueprint/camel-log.xml (not sure whether it's the right syntax)

    <bean id="kubernetesClient" class="io.fabric8.kubernetes.client.osgi.ManagedKubernetesClient" factory-method="activate">
        <argument value="java.util.Map" />
    </bean>

But I keep getting NullPointerException, it doesn't look like ManagedKubernetesClient is getting initialized or activated.

[rohanKanojia]

@mattrpav : polite ping, Did you manage to find time to look into this? It would be really helpful if you could provide a simple reproducer .

The reproducer I prepared doesn't seem to be calling ManagedKubernetesClient.activate() method which results in NPE