}

		if errors.IsNotFound(err) {
			return nil
		}

		return err
	}, newRetryOptions(opts...)...)
}

// NamespaceExists returns true if the given namespace exists.
func NamespaceExists(a kubernetes.Interface, ns string) bool {
	allNs, err := a.CoreV1().Namespaces().List(context.TODO(), metav1.ListOptions{})
	if err != nil {
		return false
	}

	"k8s.io/client-go/kubernetes"
	corev1listers "k8s.io/client-go/listers/core/v1"
	api "k8s.io/kubernetes/pkg/apis/core"
)

// PluginName indicates name of admission plugin.
const PluginName = "NamespaceExists"

// Register registers a plugin
func Register(plugins *admission.Plugins) {
	plugins.Register(PluginName, func(config io.Reader) (admission.Interface, error) {
		return NewExists(), nil
	})
}

	autoprovision.PluginName,                // NamespaceAutoProvision
	lifecycle.PluginName,                    // NamespaceLifecycle
	exists.PluginName,                       // NamespaceExists
	antiaffinity.PluginName,                 // LimitPodHardAntiAffinityTopology
	limitranger.PluginName,                  // LimitRanger
	serviceaccount.PluginName,               // ServiceAccount

		prefix:   name,
		name:     name,
		skipDump: cfg.SkipDump,
	}

	id := ctx.TrackResource(n)
	n.id = id

	if err := n.forEachCluster(func(_ int, c cluster.Cluster) error {
		if !kube2.NamespaceExists(c.Kube(), name) {
			return n.createInCluster(c, cfg)
		}
		return nil
	}); err != nil {
		return nil, err
	}

	return n, nil
}

- If you upgrade your apiserver to 1.4.x but leave your kubelets at 1.3.x, they will not report init container status, but init containers will work properly.  Upgrading kubelets to 1.4.x fixes this.
- The NamespaceExists and NamespaceAutoProvision admission controllers have been removed, use the NamespaceLifecycle admission controller instead (#31250, @derekwaynecarr)

    * NOTE: anonymous access is enabled by default. If you rely on authentication alone to authorize access, change to use an authorization mode other than AlwaysAllow, or or set '--anonymous-auth=false'.
* The NamespaceExists and NamespaceAutoProvision admission controllers have been removed. ([#31250](https://github.com/kubernetes/kubernetes/pull/31250), [@derekwaynecarr](https://github.com/derekwaynecarr))