drop rest.ConnectRequest in webhook admission

[mikedanese]

Instead of trying to convert them to something they are not.

This mitigates #59759 by turning an INTERNAL error into a successful
admission request that omits some of the request information. Eventually
we will probably want to forward CONNECT options, but they aren't
currently versioned.

cc @cjcullen @alexcope @kubernetes/sig-api-machinery-pr-reviews

NONE

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[k8s-ci-robot]

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[liggitt]

What object do in-tree admission plugins get in admission attributes for these requests?

[mikedanese]

they get *rest.ConnectRequests:

kubernetes/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/rest.go

Lines 125 to 138 in f1b6611

	if mutatingAdmission, ok := admit.(admission.MutationInterface); ok {
	err = mutatingAdmission.Admit(admission.NewAttributesRecord(connectRequest, nil, scope.Kind, namespace, name, scope.Resource, scope.Subresource, admission.Connect, userInfo))
	if err != nil {
	scope.err(err, w, req)
	return
	}
	}
	if validatingAdmission, ok := admit.(admission.ValidationInterface); ok {
	err = validatingAdmission.Validate(admission.NewAttributesRecord(connectRequest, nil, scope.Kind, namespace, name, scope.Resource, scope.Subresource, admission.Connect, userInfo))
	if err != nil {
	scope.err(err, w, req)
	return
	}
	}

e.g.:

kubernetes/plugin/pkg/admission/exec/admission.go

Line 97 in f1b6611

connectRequest, ok := a.GetObject().(*rest.ConnectRequest)

[fedebongio]

/cc @caesarxuchao

[caesarxuchao]

@mikedanese I'm working on a complete fix at #66807. I tried locally it seemed to work.

[mikedanese]

Let's go with #66807