Kubernetes: kubeadm は ABAC を正しくサポートしていません

これはバグレポートですか、それとも機能要求ですか? :
/種類のバグ

何が起こった:
以下の構成ファイルを使用して ABAC 認証を有効にして、 kubeadmツールを使用してクラスターを作成しようとしました。

~/config.yaml

apiVersion: kubeadm.k8s.io/v1alpha1
kind: MasterConfiguration
networking:
  podSubnet: 10.244.0.0/16
authorizationModes:
- Node
- RBAC
- ABAC
apiServerExtraArgs:
  basic-auth-file: /etc/kubernetes/basic_auth.csv
  authorization-policy-file: /etc/kubernetes/abac_policy.json

~/basic_auth.csv

admin,admin,1,"system:masters"

~/abac_policy.json

{"apiVersion": "abac.authorization.kubernetes.io/v1beta1", "kind": "Policy", "spec": {"user":"*", "nonResourcePath": "*", "readonly": true}}
{"apiVersion": "abac.authorization.kubernetes.io/v1beta1", "kind": "Policy", "spec": {"user":"admin", "namespace": "*", "resource": "*", "apiGroup": "*"}}
{"apiVersion": "abac.authorization.kubernetes.io/v1beta1", "kind": "Policy", "spec": {"group":"system:serviceaccounts", "namespace": "*", "resource": "*", "apiGroup": "*", "nonResourcePath": "*"}}

kubeadmコマンドは、次の出力でハングします...

[init] Using Kubernetes version: v1.9.3
[init] Using Authorization modes: [Node RBAC ABAC]
[preflight] Running pre-flight checks.
        [WARNING FileExisting-crictl]: crictl not found in system path
[preflight] Starting the kubelet service
[certificates] Generated ca certificate and key.
[certificates] Generated apiserver certificate and key.
[certificates] apiserver serving cert is signed for DNS names [k8s-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [####### #######]
[certificates] Generated apiserver-kubelet-client certificate and key.
[certificates] Generated sa key and public key.
[certificates] Generated front-proxy-ca certificate and key.
[certificates] Generated front-proxy-client certificate and key.
[certificates] Valid certificates and keys now exist in "/etc/kubernetes/pki"
[kubeconfig] Wrote KubeConfig file to disk: "admin.conf"
[kubeconfig] Wrote KubeConfig file to disk: "kubelet.conf"
[kubeconfig] Wrote KubeConfig file to disk: "controller-manager.conf"
[kubeconfig] Wrote KubeConfig file to disk: "scheduler.conf"
[controlplane] Wrote Static Pod manifest for component kube-apiserver to "/etc/kubernetes/manifests/kube-apiserver.yaml"
[controlplane] Wrote Static Pod manifest for component kube-controller-manager to "/etc/kubernetes/manifests/kube-controller-manager.yaml"
[controlplane] Wrote Static Pod manifest for component kube-scheduler to "/etc/kubernetes/manifests/kube-scheduler.yaml"
[etcd] Wrote Static Pod manifest for a local etcd instance to "/etc/kubernetes/manifests/etcd.yaml"
[init] Waiting for the kubelet to boot up the control plane as Static Pods from directory "/etc/kubernetes/manifests".
[init] This might take a minute or longer if the control plane images have to be pulled.

kube-apiserverコンテナは常に再起動されているようです。

kube-apiserverコンテナーからのログ出力は、

I0306 12:39:33.179719       1 server.go:121] Version: v1.9.3
invalid authentication config: open /etc/kubernetes/basic_auth.csv: no such file or directory

あなたが期待したこと:
kube-apiserverが始まると思っていました。

それを再現する方法 (最小限かつ正確に) :

mkdir -p /etc/kubernetes
cp ~/basic_auth.csv /etc/kubernetes
cp ~/abac_policy.json /etc/kubernetes
kubeadm init --config ~/config.yaml

他に知っておくべきことはありますか? :

環境:

• Kubernetes バージョン ( kubectl version ): v1.9.3
• クラウドプロバイダーまたはハードウェア構成: ベアメタル
• OS (例: /etc/os-release から): 16.04.4 LTS (Xenial Xerus)
• カーネル (例: uname -a ): Linux k8s-master 4.4.0-116-generic #140-Ubuntu SMP Mon Feb 12 21:23:04 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
• ツールをインストールします。
• その他: