kubernetes rbac 授权层似乎给出了不正确的结果

Question

我试图更好地理解 Kubernetes 中的 RBAC。遇到这种意外情况，使用kubectl auth can-i进行授权测试和实际结果不同。简而言之，按照这个测试，新创建的用户应该无法获取 pod，但是这个用户实际上可以获取 pod。

版本：

$ kubectl version
Client Version: version.Info{Major:"1", Minor:"11", GitVersion:"v1.11.1", GitCommit:"b1b29978270dc22fecc592ac55d903350454310a", GitTreeState:"clean", BuildDate:"2018-07-17T18:53:20Z", GoVersion:"go1.10.3", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"11", GitVersion:"v1.11.1", GitCommit:"b1b29978270dc22fecc592ac55d903350454310a", GitTreeState:"clean", BuildDate:"2018-07-17T18:43:26Z", GoVersion:"go1.10.3", Compiler:"gc", Platform:"linux/amd64"}

为有问题的用户配置kubectl：

$ kubectl config view --minify
apiVersion: v1
clusters:
- cluster:
    certificate-authority: /home/master/ca.pem
    server: https://192.168.1.111:6443
  name: jdoe
contexts:
- context:
    cluster: jdoe
    user: jdoe
  name: jdoe
current-context: jdoe
kind: Config
preferences: {}
users:
- name: jdoe
  user:
    client-certificate: /home/master/jdoe.pem
    client-key: /home/master/jdoe-key.pem

针对授权层的测试表明 jdoe 无法获取 pod。

$ kubectl auth can-i get pods --as jdoe
no

但是，jdoe 可以获取 pod：

$ kubectl get pods --all-namespaces
NAMESPACE       NAME                                       READY     STATUS    RESTARTS   AGE
ingress-nginx   nginx-ingress-controller-87554c57b-ttgwp   1/1       Running   0          5h
kube-system     coredns-5f7d467445-ngnvf                   1/1       Running   0          1h
kube-system     coredns-5f7d467445-wwf5s                   1/1       Running   0          5h
kube-system     weave-net-25kq2                            2/2       Running   0          5h
kube-system     weave-net-5njbh                            2/2       Running   0          4h

切换回管理上下文后，从身份验证层得到了类似的结果：

$ kubectl config use-context kubernetes
Switched to context "kubernetes".
$ kubectl config view --minify
apiVersion: v1
clusters:
- cluster:
    certificate-authority-data: REDACTED
    server: https://192.168.1.111:6443
  name: kubernetes
contexts:
- context:
    cluster: kubernetes
    user: admin
  name: kubernetes
current-context: kubernetes
kind: Config
preferences: {}
users:
- name: admin
  user:
    client-certificate: /home/master/admin.pem
    client-key: /home/master/admin-key.pem

从这里开始，用户 jdoe 也不应该获得 pod。

$ kubectl auth can-i get pods --as jdoe
no

kubectl config view的输出

$ kubectl config view 
apiVersion: v1
clusters:
- cluster:
    certificate-authority: /home/master/ca.pem
    server: https://192.168.1.111:6443
  name: jdoe
- cluster:
    certificate-authority-data: REDACTED
    server: https://192.168.1.111:6443
  name: kubernetes
- cluster:
    certificate-authority: /home/master/ca.pem
    server: https://192.168.1.111:6443
  name: master
contexts:
- context:
    cluster: jdoe
    user: jdoe
  name: jdoe
- context:
    cluster: kubernetes
    user: admin
  name: kubernetes
- context:
    cluster: master
    user: master
  name: master
current-context: kubernetes
kind: Config
preferences: {}
users:
- name: admin
  user:
    client-certificate: /home/master/admin.pem
    client-key: /home/master/admin-key.pem
- name: jdoe
  user:
    client-certificate: /home/master/jdoe.pem
    client-key: /home/master/jdoe-key.pem
- name: master
  user:
    client-certificate: /home/master/master.pem
    client-key: /home/master/master-key.pem

Answer 1

kubectl get pods 没有特定的 pod 名称实际上是一个列表。有关给定请求对应的动词的详细信息，请参阅https://kubernetes.io/docs/reference/access-authn-authz/authorization/#determine-the-request-verb。

can-i list pods 返回什么？