kubernetes - 如何设置 kubernetes RBAC 资源以便 pod 可以通过客户端访问 API？

Question

问题

我有一个简单的 RBAC 配置来访问集群内的 Kubernetes API。然而，我从 kubectl 得到的信息似乎是相互冲突的。部署 list 后，RBAC 似乎已正确设置。

$ kubectl exec -ti pod/controller -- kubectl auth can-i get namespaces
Warning: resource 'namespaces' is not namespace scoped
yes

但是，实际发出请求会产生权限错误

$ kubectl exec -ti pod/controller -- kubectl get namespaces
Error from server (Forbidden): namespaces is forbidden: User "system:serviceaccount:default:controller" cannot list resource "namespaces" in API group "" at the cluster scope
command terminated with exit code 1

list

apiVersion: 'v1'
kind: 'ServiceAccount'
metadata:
  name: 'controller'
---

apiVersion: 'rbac.authorization.k8s.io/v1'
kind: 'Role'
metadata:
  name: 'read-namespaces'
rules:
  - apiGroups:
      - ''
    resources:
      - 'namespaces'
    verbs:
      - 'get'
      - 'watch'
      - 'list'
---

apiVersion: 'rbac.authorization.k8s.io/v1'
kind: 'RoleBinding'
metadata:
  name: 'read-namespaces'
roleRef:
  apiGroup: ''
  kind: 'Role'
  name: 'read-namespaces'
subjects:
  - kind: 'ServiceAccount'
    name: 'controller'
---

apiVersion: 'v1'
kind: 'Pod'
metadata:
  name: 'controller'
  labels:
    'app': 'controller'
spec:
  containers:
    - name: 'kubectl'
      image: 'bitnami/kubectl:latest'
      imagePullPolicy: 'Always'
      command:
        - 'sleep'
        - '3600'
  serviceAccountName: 'controller'
---

其他信息

我尝试过 kubectl auth reconcile -f manifest.yaml 以及 kubectl apply -f manifest.yaml，结果是相同的。

我还将“read-namespaces”RoleBinding.subjects[0].namespace 设置为正确的命名空间(在本例中为“默认”)。输出没有变化。

Answer 1

命名空间是集群范围的资源。因此，您需要一个 ClusterRole 和一个 ClusterRoleBinding。

apiVersion: 'rbac.authorization.k8s.io/v1'
kind: 'ClusterRole'
metadata:
  name: 'read-namespaces'
rules:
  - apiGroups:
      - ''
    resources:
      - 'namespaces'
    verbs:
      - 'get'
      - 'watch'
      - 'list'
---

apiVersion: 'rbac.authorization.k8s.io/v1'
kind: 'ClusterRoleBinding'
metadata:
  name: 'read-namespaces'
roleRef:
  apiGroup: 'rbac.authorization.k8s.io'
  kind: 'ClusterRole'
  name: 'read-namespaces'
subjects:
  - kind: 'ServiceAccount'
    name: 'controller'
---