fix: include node events with null involvedObject.uid in describe output

[vigneshakaviki]

What type of PR is this?

/kind bug

What this PR does / why we need it

kubectl describe node omits events where involvedObject.uid is unset/null. This happens with kubelet-emitted node status events on some clusters (e.g. EKS), where kubelet creates events with involvedObject.uid: null but valid involvedObject.kind=Node and involvedObject.name=<node>.

Currently NodeDescriber.Describe() searches for events using two UIDs:

1. The node's real UID (for controller events)
2. The node name as UID (for kubelet events using the name workaround)

Neither matches events where involvedObject.uid is null/empty.

How does this PR fix it

Adds a third search with empty UID (matching by kind+name only) and deduplicates the merged results using event UIDs to avoid showing duplicate entries.

Which issue(s) this PR fixes

Fixes #1838

Does this PR introduce a user-facing change?

Fixed kubectl describe node to show events where involvedObject.uid is null, such as kubelet-emitted node status events on some clusters.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: vigneshakaviki / name: vigneshakaviki (e976d59)

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[vigneshakaviki]

Hi @marinoborges, I took a shot at fixing this. The approach adds a third event search with an empty UID (matching by kind+name only) alongside the existing two searches (real UID and name-as-UID), then deduplicates the merged results.

Could a sig/cli reviewer take a look and let me know if this approach is reasonable? Happy to adjust if there's a preferred way to handle this.

/cc @soltysh

[vigneshakaviki]

Verified end-to-end on a local minikube cluster

Setup: Created a test event with involvedObject.uid unset:

apiVersion: v1
kind: Event
metadata:
  name: test-null-uid-event
  namespace: default
involvedObject:
  apiVersion: v1
  kind: Node
  name: minikube
type: Warning
reason: TestNullUID
message: "This is a test event with null involvedObject.uid"

Confirmed involvedObject has no uid field:

{"apiVersion": "v1", "kind": "Node", "name": "minikube"}

Stock kubectl — event is missing:

$ kubectl describe node minikube | grep TestNullUID
(no output — bug confirmed)

Patched kubectl (built with this PR's changes) — event is shown:

$ ./kubectl-patched describe node minikube
Events:
  Type     Reason                   Age                  From             Message
  ----     ------                   ----                 ----             -------
  Normal   Starting                 110s                 kube-proxy       
  Warning  TestNullUID              17h                                   This is a test event with null involvedObject.uid
  Normal   Starting                 115s                 kubelet          Starting kubelet.
  Normal   NodeHasSufficientMemory  115s (x8 over 115s)  kubelet          Node minikube status is now: NodeHasSufficientMemory
  ...

[soltysh]

/close

@vigneshakaviki please open this PR against https://github.com/kubernetes/kubernetes/

This repository is only a read-only copy from https://github.com/kubernetes/kubernetes/tree/master/staging/src/k8s.io/kubectl/. You can read more about it in https://github.com/kubernetes/kubectl/blob/master/README.md

[k8s-ci-robot]

@soltysh: Closed this PR.

Details

In response to this:

/close

@vigneshakaviki please open this PR against https://github.com/kubernetes/kubernetes/

This repository is only a read-only copy from https://github.com/kubernetes/kubernetes/tree/master/staging/src/k8s.io/kubectl/. You can read more about it in https://github.com/kubernetes/kubectl/blob/master/README.md

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[vigneshakaviki]

Reopened at kubernetes/kubernetes#138362 per @soltysh's direction. Thanks for the pointer!