Which Knative version is compatible with Fabric8 Kubernetes Client 7.1.0

[iampratapak]

After upgrading the Kubernetes client to version 7.1.0, we encounter the following error when updating Knative Services:

Caused by: java.lang.RuntimeException: io.fabric8.kubernetes.client.KubernetesClientException: Failure executing: POST at: https://10.96.0.1:443/apis/serving.knative.dev/v1/namespaces/dx-prod/services. Message: admission webhook "webhook.serving.knative.dev" denied the request: mutation failed: cannot decode incoming new object: json: cannot unmarshal object into Go struct field Condition.status.conditions.lastTransitionTime of type string. Received status: Status(apiVersion=v1, code=400, details=null, kind=Status, message=admission webhook "webhook.serving.knative.dev" denied the request: mutation failed: cannot decode incoming new object: json: cannot unmarshal object into Go struct field Condition.status.conditions.lastTransitionTime of type string, metadata=ListMeta(_continue=null, remainingItemCount=null, resourceVersion=null, selfLink=null, additionalProperties={}), reason=BadRequest, status=Failure, additionalProperties={})

The lastTransitionTime field type in knative-model:7.1.0 has changed from string to VolatileTime. This change is the root cause.

We verified that the lastTransitionTime field type is string in both Knative Serving CRDs 1.15.2 and 1.16.2.
v1.15.2/serving-crds.yaml
v1.16.2/serving-crds.yaml

Therefore, which Knative Serving version is compatible with Kubernetes client 7.1.0?

Note: Editing the Knative Service via kubectl does not produce this error. This issue occurs only with the Fabric8 Kubernetes client.

@manusa @rohanKanojia

[andreaTP]

@iampratapak quick question, have you attempted to use the java-generator targeting the exact CRD version that is installed in your cluster?

[manusa]

The model is generated from Go sources
I understand the problem came from #6448

Which changed this line:

kubernetes-client/extensions/knative/model/src/generated/java/io/fabric8/knative/pkg/apis/Condition.java

Lines 104 to 110 in c5f6674

	/**
	* Condition defines a readiness condition for a Knative resource. See: https://github.com/kubernetes/community/blob/master/contributors/devel/sig-architecture/api-conventions.md#typical-status-properties
	*/
	@JsonProperty("lastTransitionTime")
	public VolatileTime getLastTransitionTime() {
	return lastTransitionTime;
	}

This is a bug since the Go side doesn't know how to unmarshal this.

[manusa]

I opened #6906

[iampratapak]

Thanks, @manusa. Can we expect the fix in the next Kubernetes client release?

[manusa]

If everything goes well, yes

[iampratapak]

@andreaTP Unfortunately, no. I have never attempted this. Do you have documentation on how to do it? We are currently using Knative v1.15.2, and it appears that the lastTransitionTime field changed from string to date-time in v1.2.0
v1.2.0/serving-crds.yaml

[andreaTP]

@iampratapak you can follow the official documentation and there are a bunch of examples in the wild ( e.g. ), if the project you are working on is open source I can have a quick look too.

[iampratapak]

Thanks, @andreaTP. My project isn't open source. I'll read through the documentation.