return fmt.Errorf("expected a single webhook for default revision")
	}
	webhook := whs[0]
	for i := range webhook.Webhooks {
		wh := webhook.Webhooks[i]
		// this is an abomination, but if this isn't a per-revision webhook, we want to make it ineffectual
		// without deleting it. Add a nonsense match.
		wh.NamespaceSelector = util.NeverMatch
		wh.ObjectSelector = util.NeverMatch
		webhook.Webhooks[i] = wh
	}

		if len(wh.Webhooks) != tc.numWebhooks {
			t.Errorf("expected %d webhook(s) in MutatingWebhookConfiguration, found %d",
				tc.numWebhooks, len(wh.Webhooks))
		}
		tag, exists := wh.ObjectMeta.Labels[IstioTagLabel]
		if !exists {
			t.Errorf("expected tag webhook to have %s label, did not find", IstioTagLabel)
		}
		if tag != tc.tagName {

  //
  // Never: the webhook will not be called more than once in a single admission evaluation.
  //
  // IfNeeded: the webhook will be called at least one additional time as part of the admission evaluation
  // if the object being admitted is modified by other admission plugins after the initial webhook call.
  // Webhooks that specify this option *must* be idempotent, able to process objects they previously admitted.

	// Get a list of control planes which are installed in remote clusters
	// In this case, it is possible that they only have webhooks installed.
	webhooks, err := Webhooks(context.Background(), client)
	if err != nil {
		return nil, fmt.Errorf("error while listing mutating webhooks: %v", err)
	}
	for _, hook := range webhooks {
		rev := renderWithDefault(hook.GetLabels()[label.IoIstioRev.Name], DefaultRevisionName)

  // Allowed values are "Never" and "IfNeeded".
  //
  // Never: the webhook will not be called more than once in a single admission evaluation.
  //
  // IfNeeded: the webhook will be called at least one additional time as part of the admission evaluation
  // if the object being admitted is modified by other admission plugins after the initial webhook call.

		row.Cells = append(row.Cells, table.NewCell(wa.Reason))
		return row
	})
	w.AddHeader("WEBHOOK", "REVISION", "INJECTED", "REASON")
	injectedTotal := 0
	for _, ws := range was {
		if ws.Injected {
			injectedTotal++
		}
		w.AddRow(ws)
	}
	w.Flush()
	if injectedTotal > 1 {
		fmt.Fprintf(writer, "ERROR: multiple webhooks will inject, which can lead to errors")
	}
	return nil
}

      operator: NotIn
      values:
      - "false"
    - key: istio.io/rev
      operator: In
      values:
      - "{{ $tagName }}"

{{- /* When the tag is "default" we want to create webhooks for the default revision */}}
{{- /* These webhooks should be kept in sync with istio-discovery/templates/mutatingwebhook.yaml */}}
{{- if (eq $tagName "default") }}

{{- /* Case 1: Namespace selector enabled, and object selector is not injected */}}

apiVersion: admissionregistration.k8s.io/v1
kind: MutatingWebhookConfiguration
metadata:
  labels:
    app: sidecar-injector
  name: w-istio-sidecar-injector-istio-system

webhooks:
- admissionReviewVersions:
  - v1beta1
  - v1
  clientConfig:
    service:
      name: istiod
      namespace: istio-system
      path: /inject
      port: 443
  failurePolicy: Fail

	"istio.io/istio/pkg/kube"
)

func TestTagList(t *testing.T) {
	tcs := []struct {
		name          string
		webhooks      admitv1.MutatingWebhookConfigurationList
		namespaces    corev1.NamespaceList
		outputMatches []string
		error         string
	}{
		{
			name: "TestBasicTag",
			webhooks: admitv1.MutatingWebhookConfigurationList{
				Items: []admitv1.MutatingWebhookConfiguration{
					{

    - pods
    scope: '*'
  sideEffects: None
  timeoutSeconds: 10
---
# same webhook but with different name, will result in a duplicate
apiVersion: admissionregistration.k8s.io/v1
kind: MutatingWebhookConfiguration
metadata:
  labels:
    app: sidecar-injector
    istio.io/tag: default
  name: w2-istio-sidecar-injector-istio-system

webhooks:
- admissionReviewVersions:
  - v1beta1
  - v1
  clientConfig:
    service: