forbidden: User , "code": 使用 curl 访问 kube-apiserver 时出现 403 错误

Question

Kubernetes 版本：v1.19.0

我已经创建了一个用户并使用角色 cluster-admin 执行了 clusterrolebinding。

[root@project1-master ~]# kubectl describe clusterrole cluster-admin
Name:         cluster-admin
Labels:       kubernetes.io/bootstrapping=rbac-defaults
Annotations:  rbac.authorization.kubernetes.io/autoupdate: true
PolicyRule:
  Resources  Non-Resource URLs  Resource Names  Verbs
  ---------  -----------------  --------------  -----
  *.*        []                 []              [*]
             [*]                []              [*]

[root@project1-master ~]# kubectl describe clusterrolebinding sajeesh  cluster-admin
Name:         sajeesh
Labels:       <none>
Annotations:  <none>
Role:
  Kind:  ClusterRole
  Name:  cluster-admin
Subjects:
  Kind  Name     Namespace
  ----  ----     ---------
  User  sajeesh


Name:         cluster-admin
Labels:       kubernetes.io/bootstrapping=rbac-defaults
Annotations:  rbac.authorization.kubernetes.io/autoupdate: true
Role:
  Kind:  ClusterRole
  Name:  cluster-admin
Subjects:
  Kind   Name            Namespace
  ----   ----            ---------
  Group  system:masters

I am able to run kubectl with this useraccount and get pods information :

[root@project1-master ~]# kubectl get pods --as sajeesh
NAME    READY   STATUS    RESTARTS   AGE
busyb   1/1     Running   3          21h

But when i try to access kube-apiserver using curl it show forbidden error as following :

[root@project1-master ~]# curl --cacert /etc/kubernetes/pki/ca.crt --cert sajeesh.crt --key sajeesh.key https://$IP:6443/api/v1/namespaces/default/pods/busyb
{
  "kind": "Status",
  "apiVersion": "v1",
  "metadata": {

  },
  "status": "Failure",
  "message": "pods \"busyb\" is forbidden: User \"system:anonymous\" cannot get resource \"pods\" in API group \"\" in the namespace \"default\"",
  "reason": "Forbidden",
  "details": {
    "name": "busyb",
    "kind": "pods"
  },
  "code": 403

I have re-verified the cacert , cert & key i am providing with that user account .They are correct.

Any suggestions why this is happening and how to fix it.

Answer 1

clusterrolebinding sajeesh 具有名称 sajeesh 和组 system:masters。因此证书需要 sajeesh 作为通用名称 (CN) 和 system:masters作为组织（O）。当请求转到 kubernetes API 服务器时，它将检查证书并将 CN 与 name 和 O 与 clusterrolebinding 中的 Group 匹配，如果它不匹配你得到 403 Forbidden 错误。

您可以通过运行下面的命令

验证以上内容

openssl x509 -in sajeesh.crt -text -noout

Answer 2

最终发现 problem.it 与 kubernetes 无关，但我正在使用 curl 命令。

curl --cacert /etc/kubernetes/pki/ca.crt --cert sajeesh.crt --key sajeesh.key https://$IP:6443/api/v1/namespaces/default/pods/busyb

当我将 -v 开关与命令一起使用时，它显示：

* Initializing NSS with certpath: sql:/etc/pki/nssdb
*   CAfile: /etc/kubernetes/pki/ca.crt
  CApath: none
* warning: certificate file name "sajeesh.crt" handled as nickname; please use "./sajeesh.crt" to force file name
* NSS: client certificate not found: newsajeesh.crt
* SSL connection using TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384

所以基本上它是在寻找绝对路径作为参数的输入 --cert & --key

curl --cacert /etc/kubernetes/pki/ca.crt --cert ./sajeesh.crt --key ./sajeesh.key https://$IP:6443/api/v1/namespaces/default/pods/busyb

在给出绝对路径后它工作正常，我能够得到输出。

forbidden: User , "code": 使用 curl 访问 kube-apiserver 时出现 403 错误

forbidden: User , "code": 403 error while accessing kube-apiserver using curl

rbac

kubernetes

kube-apiserver