unstructuredJSONScheme#Decode is inconsistent about requiring Kind but not APIVersion

[liggitt]

What happened?

While making decoding paths consistent for strict and non-strict server-side decoding, we ran into an inconsistency between different parts of the decoding stack.

When submitting an unstructured request for a custom resource, both apiVersion and kind are required in the request.

When unmarshaling json into an unstructured object, the decoder requires kind to be set, but not apiVersion:

kubernetes/staging/src/k8s.io/apimachinery/pkg/apis/meta/v1/unstructured/helpers.go

Lines 340 to 342 in fbcfa33

	if len(gvk.Kind) == 0 {
	return nil, &gvk, runtime.NewMissingKindErr(string(data))
	}

Attempts to require apiVersion there as well exposed some places in unit tests that are not setting this. One of those places was kubectl edit tests, which replay real request/response fixtures.

Ideally, our decoding would consistently require kind and apiVersion, but we need to understand whether there are any currently working scenarios that are omitting apiVersion from unstructured data before we do so.

What did you expect to happen?

kind and apiVersion are consistently required

How can we reproduce it (as minimally and precisely as possible)?

n/a

Anything else we need to know?

No response

Kubernetes version

$ kubectl version
# paste output here

Cloud provider

OS version

# On Linux:
$ cat /etc/os-release
# paste output here
$ uname -a
# paste output here

# On Windows:
C:\> wmic os get Caption, Version, BuildNumber, OSArchitecture
# paste output here

Install tools

Container runtime (CRI) and version (if applicable)

Related plugins (CNI, CSI, ...) and versions (if applicable)

[apelisse]

/cc @kevindelgado
/triage accepted

[k8s-triage-robot]

This issue has not been updated in over 1 year, and should be re-triaged.

You can:

• Confirm that this issue is still relevant with /triage accepted (org members only)
• Close this issue with /close

For more details on the triage process, see https://www.kubernetes.dev/docs/guide/issue-triage/

/remove-triage accepted

[cici37]

/triage accepted

[k8s-triage-robot]

This issue has not been updated in over 1 year, and should be re-triaged.

You can:

• Confirm that this issue is still relevant with /triage accepted (org members only)
• Close this issue with /close

For more details on the triage process, see https://www.kubernetes.dev/docs/guide/issue-triage/

/remove-triage accepted

[cici37]

/triage accepted