Events retrieved via the dynamic client when converted between unstructured.Unstructured and corev1.Event are missing involvedObject

[TylerHelmuth]

I have a situation where a dynamic client is retrieving events in the cluster. The received events look like

{
    "Type": "ADDED",
    "Object": {
        "apiVersion": "events.k8s.io/v1",
        "deprecatedCount": 1,
        "deprecatedFirstTimestamp": "2023-07-20T20:27:06Z",
        "deprecatedLastTimestamp": "2023-07-20T20:27:06Z",
        "deprecatedSource": {
            "component": "replicaset-controller"
        },
        "eventTime": null,
        "kind": "Event",
        "metadata": {
            "creationTimestamp": "2023-07-20T20:27:06Z",
            "managedFields": [
                {
                    "apiVersion": "v1",
                    "fieldsType": "FieldsV1",
                    "fieldsV1": {
                        "f:count": {},
                        "f:firstTimestamp": {},
                        "f:involvedObject": {},
                        "f:lastTimestamp": {},
                        "f:message": {},
                        "f:reason": {},
                        "f:source": {
                            "f:component": {}
                        },
                        "f:type": {}
                    },
                    "manager": "kube-controller-manager",
                    "operation": "Update",
                    "time": "2023-07-20T20:27:06Z"
                }
            ],
            "name": "testing-refinery-7df6cbbdb9.1773ad4bde97125f",
            "namespace": "default",
            "resourceVersion": "34802",
            "uid": "31f2fde4-a1a1-4861-9b99-1c291ab600ee"
        },
        "note": "Created pod: testing-refinery-7df6cbbdb9-lh7c7",
        "reason": "SuccessfulCreate",
        "regarding": {
            "apiVersion": "apps/v1",
            "kind": "ReplicaSet",
            "name": "testing-refinery-7df6cbbdb9",
            "namespace": "default",
            "resourceVersion": "34777",
            "uid": "7f7fd90e-c747-4623-ac65-c32d7d9d4bb5"
        },
        "type": "Normal"
    }
}

This representation of the event uses regarding instead of involvedObject.

I try to convert these objects to corev1.Events:

func someFunction(e *watch.Event) {
    udata := e.Object.(*unstructured.Unstructured)
    unstructure := udata.UnstructuredContent()
    var event corev1.Event
    runtime.DefaultUnstructuredConverter.FromUnstructured(unstructure, &event)
        ...
}

and I am left with an event without an involvedObject:

{
    "kind": "Event",
    "apiVersion": "events.k8s.io/v1",
    "metadata": {
        "name": "testing-refinery-7df6cbbdb9.1773ad4bde97125f",
        "namespace": "default",
        "uid": "31f2fde4-a1a1-4861-9b99-1c291ab600ee",
        "resourceVersion": "34802",
        "creationTimestamp": "2023-07-20T20:27:06Z",
        "managedFields": [
            {
                "manager": "kube-controller-manager",
                "operation": "Update",
                "apiVersion": "v1",
                "time": "2023-07-20T20:27:06Z",
                "fieldsType": "FieldsV1",
                "fieldsV1": {
                    "f:count": {},
                    "f:firstTimestamp": {},
                    "f:involvedObject": {},
                    "f:lastTimestamp": {},
                    "f:message": {},
                    "f:reason": {},
                    "f:source": {
                        "f:component": {}
                    },
                    "f:type": {}
                }
            }
        ]
    },
    "involvedObject": {},
    "reason": "SuccessfulCreate",
    "source": {},
    "firstTimestamp": null,
    "lastTimestamp": null,
    "type": "Normal",
    "eventTime": null,
    "reportingComponent": "",
    "reportingInstance": ""
}

I believe the issue is that the event returned by the dynamic client has regarding instead of involvedObject like the corev1.Event struct expects.

Please let me know if this is actually an issue for the unstructured package.

[liggitt]

you are retrieving events in events.k8s.io/v1 version (corresponding to https://github.com/kubernetes/api/blob/86e8180c2c5fc26b0903248e2ec19bd30ee203bc/events/v1/types.go#L33) but then trying to coerce into v1 version objects (corresponding to https://github.com/kubernetes/api/blob/86e8180c2c5fc26b0903248e2ec19bd30ee203bc/core/v1/types.go#L6179)

You are correct the field names differ. For this to work properly, use the go types corresponding to the API group/version you are fetching (https://github.com/kubernetes/api/blob/86e8180c2c5fc26b0903248e2ec19bd30ee203bc/events/v1/types.go#L33).

[TylerHelmuth]

@liggitt thank for the explanation. Which version of the event should be preferred, v1 or events.k8s.io/v1?