Difficult to extend exception handler

[domainname]

@yue9944882 @brendandburns

It's difficult to extend exception handler in ReflectorRunnable. Controller does not expose a property for developer to inject a customized exception handler. Nor does SharedInformerFactory. One probably has to write his/her own SharedInformerFactory and Controller, in order to inject a customized exception handler.

[brendandburns]

Can you give an example of the code you would like to write or the function signature you are looking for?

We can definitely look to improve things.

Thanks!

[domainname]

Hi @brendanburns. This is a typical way to write a informer. There is nowhere to inject an exception handler.

        SharedIndexInformer<V1Deployment> deploymentInformer =
            factory.sharedIndexInformerFor(
                (CallGeneratorParams params) -> api.listDeploymentForAllNamespacesCall(
                    null, null, null, null, null,
                    null, params.resourceVersion, null, params.timeoutSeconds, params.watch,
                    null),
                V1Deployment.class, V1DeploymentList.class);
        deploymentInformer.addEventHandler(deploymentEventHandler);

The function signature is

public class SharedInformerFactory {
  ...
  public synchronized <ApiType extends KubernetesObject, ApiListType extends KubernetesListObject>
      SharedIndexInformer<ApiType> sharedIndexInformerFor(
          CallGenerator callGenerator,
          Class<ApiType> apiTypeClass,
          Class<ApiListType> apiListTypeClass);
  ...
}

I hope to see a signature like this:

  public synchronized <ApiType extends KubernetesObject, ApiListType extends KubernetesListObject>
      SharedIndexInformer<ApiType> sharedIndexInformerFor(
          CallGenerator callGenerator,
          Class<ApiType> apiTypeClass,
          Class<ApiListType> apiListTypeClass,
          BiConsumer<Class<ApiType>, Throwable> exceptionHandler);

[brendandburns]

I think I'm still confused. The DefaultSharedIndexInformer doesn't have any catch blocks in it, the ReflectorRunnable has a parameter where you can pass in the handler.

Are you talking about the Controller class, it is true that doesn't make it easy to pass in an exception handler, we could certainly add a parameter there.

Thanks!

[domainname]

SharedInformerFactory builds an instance of DefaultSharedIndexInformer. And DefaultSharedIndexInformer constructs an instance of Controller. Finally Controller instantiates ReflectorRunnable at

java/util/src/main/java/io/kubernetes/client/informer/cache/Controller.java

Line 116 in fbf4652

reflector = new ReflectorRunnable<ApiType, ApiListType>(apiTypeClass, listerWatcher, queue);

.

There is no way to pass my own exception handler to ReflectorRunnable from SharedInformerFactory. I have to write my own Controller, SharedIndexInformer and SharedInformerFactory.

[brendandburns]

Ah, yes. That path is twisty :)

We can plumb something in here. Thanks for the patience.

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[domainname]

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[domainname]

@brendandburns Hi Brendan, do you have any plan to do some improvements in custom exception handler?

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