How to handle deserialization errors?

[benkeil]

If there is a configuration that doesn’t match the actual class you specify for your reconciler, the whole application crashes.
How do you handle this? Why I can’t just deserialize the body inside the reconciler?

[csviri]

Hi @benkeil ,

this mostly comes from fabric8 Kubernetes client. There are various approaches to cope with some deserialization issue. If there are some new backwards compatible changes, you can just simply ignore those fields, by marking:

@JsonIgnoreProperties(ignoreUnknown = true)
public class MyCustomResourceSpec {
    // fields...
}

You can also customize the json ObjectMapper for the client:

new KubernetesClientBuilder().withKubernetesSerialization(...)

Having these at hand I don't see why would be a better approach to deserialize it inside the body, given also that the framework heavily relies on resource metadata (like owner references, resourceVersion, labels, etc), before event the resource triggers the reconiliation.

Note, if none above works for you, you can use still GenericKubernetesResource for Informers:

see: https://github.com/fabric8io/kubernetes-client/blob/main/kubernetes-model-generator/kubernetes-model-core/src/main/java/io/fabric8/kubernetes/api/model/GenericKubernetesResource.java

We might support this also for primary resources, but for that we need to see a strong case described, see:
#2716

hope it helps

[csviri]

Note that failing on deserialization error was a conscious decision, after quite a bit of discussion with various parties, if none of the above helps, it mean there is a fundamental issue / mismatch in you cluster and controller ( like could be missing conversion hooks some cases).