Kubernetes服务帐户没有分配角色？

编程问答 2022-08-12

问题描述

我在kubernetes中有一个服务帐户：

apiVersion: v1
kind: ServiceAccount
Metadata:
  name: testsa
  namespace: project-1

我已将其分配给view角色：

apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
Metadata:
  name: testsa-view
  namespace: project-1
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: view
subjects:
- kind: ServiceAccount
  name: testsa
  namespace: project-1

这应授予服务帐户对所有资源的读取权限。在project-1命名空间的容器中，我试图运行以下Python代码：

>>> from kubernetes import client,config
>>> config.load_incluster_config()
>>> api = client.CoreV1Api()
>>> api.list_pod_for_all_namespaces()

但这失败，并出现403错误：

kubernetes.client.rest.ApiException: (403)
Reason: Forbidden
[...]
HTTP response body: {"kind":"Status","apiVersion":"v1","Metadata":{},"status":"Failure","message":"pods is forbidden: User \"system:serviceaccount:project-1:testsa\" cannot list resource \"pods\" in API group \"\" at the cluster scope","reason":"Forbidden","details":{"kind":"pods"},"code":403}

吊舱与服务帐户相关联：

apiVersion: v1
kind: Pod
Metadata:
  labels:
    run: testsa
  name: testsa-2-l929g
  namespace: project-1
spec:
  serviceAccountName: testsa
  automountServiceAccountToken: true
  containers:
  - image: larsks/testsa
    imagePullPolicy: Always
    name: testsa
    ports:
    - containerPort: 8080
      protocol: TCP
    resources: {}

在容器内，我可以看到安装的机密：

/src $ find /run/secrets/ -type f
/run/secrets/kubernetes.io/serviceaccount/..2020_09_04_16_30_26.292719465/ca.crt
/run/secrets/kubernetes.io/serviceaccount/..2020_09_04_16_30_26.292719465/token
/run/secrets/kubernetes.io/serviceaccount/..2020_09_04_16_30_26.292719465/service-ca.crt
/run/secrets/kubernetes.io/serviceaccount/..2020_09_04_16_30_26.292719465/namespace
/run/secrets/rhsm/ca/redhat-uep.pem
/run/secrets/rhsm/ca/redhat-entitlement-authority.pem

我在这里想念什么？

解决方法

错误提示cannot list resource \"pods\" in API group \"\" at the cluster scope，因为您试图访问群集中所有名称空间的所有Pod，而不是仅访问project-1名称空间的所有Pod。

因此将Role更改为ClusterRoleBinding 

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: testsa-view
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: view
subjects:
- kind: ServiceAccount
  name: testsa
  namespace: project-1

从示例here RoleBinding引用开始，即使在引用其中的ClusterRole时，也始终授予仅限于该特定名称空间的名称空间范围资源。

您可以使用以下命令检查服务帐户的权限

kubectl auth can-i --list --as=system:serviceaccount:project-1:testsa
kubectl auth can-i --list --as=system:serviceaccount:project-1:testsa -n project-1
kubectl auth list pods --as=system:serviceaccount:project-1:testsa
kubectl auth list pods --as=system:serviceaccount:project-1:testsa -n project-1
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