Jenkinsfile中定义的podTemplate中的容器执行kubectl命令权限不够问题解决

信息说明

    笔者k8s环境是v1.16版本，Jenkins以pod形式在kube-ops的命名空间中运行，在通过动态Jenkins slave实现CI/CD时，通过Jenkinsfile自定义pod模板信息，在Jenkins slave中执行kubectl命令时，出现权限不够的报错。

    经过笔者多次调试，出现不同的权限报错信息，如下：

### 1

+ kubectl get pods

Error from server (Forbidden): pods is forbidden: User "system:serviceaccount:kube-ops:default" cannot list resource "pods" in API group "" in the namespace "kube-ops"

### 2

Error from server (Forbidden): pods is forbidden: User "system:serviceaccount:kube-ops:default" cannot list resource "pods" in API group "" in the namespace "kube-ops"

问题解决

    笔者之前在Jenkins的系统配置里添加过kubernets的pod模板信息，能正常执行kubectl命令，但是将其整合到自定义的Jenkinsfile文件中，便出现此报错。

    个人根据原有的页面pod配置和Jenkinsfile中的pod配置对比，发现前者比后者多了项 serverAccout 的配置，故我试着在Jenkinsfile的podTemplate中添加 serverAccout，如图：

　 

    因为在不同的kubernets集群中，jenkins的rbac权限可能不同，故有些人加了 serviceAccount: 'jenkins' 也没解决问题，究其原因是 jenkins 的rbac权限配置未达到执行kubectl命令的要求，故提供下述yaml文件，并在k8s中应用即可。

# cat rbac-jenkins.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: jenkins
  namespace: kube-ops

---

kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: jenkins
rules:
  - apiGroups: ["extensions", "apps"]
    resources: ["deployments"]
    verbs: ["create", "delete", "get", "list", "watch", "patch", "update"]
  - apiGroups: [""]
    resources: ["services"]
    verbs: ["create", "delete", "get", "list", "watch", "patch", "update"]
  - apiGroups: [""]
    resources: ["pods"]
    verbs: ["create","delete","get","list","patch","update","watch"]
  - apiGroups: [""]
    resources: ["pods/exec"]
    verbs: ["create","delete","get","list","patch","update","watch"]
  - apiGroups: [""]
    resources: ["pods/log"]
    verbs: ["get","list","watch"]
  - apiGroups: [""]
    resources: ["secrets"]
    verbs: ["get"]
  - apiGroups: [""]
    resources: ["events"]
    verbs: ["get","list","watch"]

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: jenkins
  namespace: kube-ops
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: jenkins
subjects:
  - kind: ServiceAccount
    name: jenkins
    namespace: kube-ops

# kubectl apply -f rbac-jenkins.yaml

# 添加完成后触发构建，显示正常，如图：

参考文档

https://github.com/jenkinsci/kubernetes-plugin/blob/master/README.md