kubeconfig的使用

1. kubeconfig说明

默认情况下，kubectl 在 $HOME/.kube 目录下查找名为 config 的文件。你可以通过设置 KUBECONFIG 环境变量或者设置 --kubeconfig参数来指定其他 kubeconfig 文件。

kubeconfig内容示例：

以下证书以文件的形式读取。

apiVersion: v1
kind: Config
clusters:
- cluster:
    certificate-authority: */ca.crt
    server: https://******
  name: demo
contexts:
- context:
    cluster: demo
    user: demo
  name: demo
current-context: demo
preferences: {}
users:
- name: demo
  user:
    client-certificate: */client.crt
    client-key: */client.key

2. 将 Kubeconfig 中的证书文件转为证书数据

2.1. 证书文件转为证书数据

如果需要将证书文件替换为证书数据格式，可以通过base64的命令解码成data数据，同时修改相应的参数。

获取证书文件的 base64 编码：

cat "证书文件" | base64

将输出结果的换行符去掉，填到对应证书的data中。

将 certificate-authority 改为 certificate-authority-data，并且将 */ca.crt 证书文件经 base64 编码后的字符串填入该位置。
将 client-certificate 改为 client-certificate-data，并且将 */client.crt 证书文件经 base64 编码后的字符串填入该位置。
将 client-key 改为 client-key-data，并且将 */client.key 证书文件 base64 编码后的字符串填入该位置。

例如：

apiVersion: v1
kind: Config
clusters:
- cluster:
    certificate-authority-data: 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
    server: https://******
  name: demo
contexts:
- context:
    cluster: demo
    user: demo
  name: demo
current-context: demo
preferences: {}
users:
- name: demo
  user:
    client-certificate-data: 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
    client-key-data: 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

2.2. 证书数据转成证书文件

grep 'certificate-authority-data' /etc/kubernetes/admin.conf | head -n 1 | awk '{print $2}' | base64 -d > ca.crt
grep 'client-key-data' /etc/kubernetes/admin.conf | head -n 1 | awk '{print $2}' | base64 -d > client.key
grep 'client-certificate-data' /etc/kubernetes/admin.conf | head -n 1 | awk '{print $2}' | base64 -d > client.crt

3. 生成集群级别的kubeconfig

3.1. 创建ServiceAccount

# 1. 创建用户
cat<<EOF | kubectl apply -f -
apiVersion: v1
kind: ServiceAccount
metadata:
  namespace: ${ServiceAccountNS}
  name: ${ServiceAccountName}
EOF

# 2. 创建Secret绑定ServiceAccount
# k8s 1.24后的版本不再自动生成secret，绑定后当删除ServiceAccount时会自动删除secret
cat<<EOF | kubectl apply -f -
apiVersion: v1
kind: Secret
metadata:
  name: ${SecretName}
  namespace: ${ServiceAccountNS}
  annotations:
    kubernetes.io/service-account.name: "${ServiceAccountName}"   
type: kubernetes.io/service-account-token
EOF

3.2. 创建和绑定权限

如果不创建自定义权限，可以使用自带的ClusterRole: cluster-admin/admin/edit/view。如果需要生成集群admin的权限，可以绑定 cluster-admin的权限。建议权限授权时遵循最小权限原则。即需要使用的权限授权，不需要使用的权限不授权，对于删除等敏感权限慎重授权。

如果要创建自定义权限，使用ClusterRole和ClusterRoleBinding的对象。

只读权限：verbs: ["get","list","watch"]
可写权限：verbs: ["create","update","patch","delete","deletecollection"]
全部权限：verbs: ["*"]

# 3. 创建权限: 可以自定义权限，或者使用clusterrole: cluster-admin/admin/edit/view权限
# 只读权限：verbs: ["get","list","watch"]
# 可写权限：verbs: ["create","update","patch","delete","deletecollection"]
# 全部权限：verbs: ["*"]
cat<<EOF | kubectl apply -f -
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: ${ClusterRoleName}
rules:
- apiGroups: ["*"]
  resources: ["pods","deployments"]
  verbs: ["*"]
EOF

# 4. 绑定权限
cat<<EOF | kubectl apply -f -
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: ${ClusterRoleBindingName}
subjects:
- kind: ServiceAccount
  name: ${ServiceAccountName}
  namespace: ${ServiceAccountNS}
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: ${ClusterRoleName}
EOF

3.3. 创建kubeconfig

# 5. 基于secret获取token
TOKEN=$(kubectl get secret ${SecretName} -n ${ServiceAccountNS} -o jsonpath={".data.token"} | base64 -d)

# 6. 创建kubeconfig文件
kubectl --kubeconfig=${KubeDir}/${USER}.yaml config set-cluster ${KubeConfigCluster} \
  --server=https://${APISERVER} \
  --certificate-authority=${CaFilePath} \
  --embed-certs=true
kubectl --kubeconfig=${KubeDir}/${USER}.yaml config set-credentials ${USER} --token=${TOKEN}
kubectl --kubeconfig=${KubeDir}/${USER}.yaml config set-context ${USER}@${KubeConfigCluster} --cluster=${KubeConfigCluster} --user=${USER}
kubectl --kubeconfig=${KubeDir}/${USER}.yaml config use-context ${USER}@${KubeConfigCluster}
kubectl --kubeconfig=${KubeDir}/${USER}.yaml config view

4. 生成namespace的kubeconfig

4.1. 创建ServiceAccount

创建ServiceAccout同上，没有区别。

4.2. 创建和绑定权限

创建namespace级别的权限用Role和RoleBinding的对象。一个ServiceAccount可以绑定多个权限，可以通过创建ClusterRoleBinding或RoleBinding来实现对多个namespace的权限控制。

# 3. 创建权限: 可以自定义权限，或者使用clusterrole: admin/edit/view权限
cat<<EOF | kubectl apply -f -
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  namespace: ${USER_NAMESPACE}
  name: ${RoleName}
rules:
- apiGroups: ["*"] 
  resources: ["pods"]
  verbs: ["*"]
EOF

# 4. 绑定权限
cat<<EOF | kubectl apply -f -
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: ${RoleBindingName}
  namespace: ${USER_NAMESPACE}
subjects:
- kind: ServiceAccount
  name: ${ServiceAccountName}
  namespace: ${ServiceAccountNS}
roleRef:
  kind: Role
  name: ${RoleName}
  apiGroup: rbac.authorization.k8s.io
EOF

4.3. 创建kubeconfig

# 5. 基于secret获取token
TOKEN=$(kubectl get secret ${SecretName} -n ${ServiceAccountNS} -o jsonpath={".data.token"} | base64 -d)

# 6. 创建kubeconfig文件
kubectl --kubeconfig=${KubeDir}/${USER}.yaml config set-cluster ${KubeConfigCluster} \
  --server=https://${APISERVER} \
  --certificate-authority=${CaFilePath} \
  --embed-certs=true
kubectl --kubeconfig=${KubeDir}/${USER}.yaml config set-credentials ${USER} --token=${TOKEN}
# 与cluster级别kubeconfig不同的增加了--namespace
kubectl --kubeconfig=${KubeDir}/${USER}.yaml config set-context ${USER}@${KubeConfigCluster} \
  --cluster=${KubeConfigCluster} --user=${USER} --namespace=${USER_NAMESPACE}
kubectl --kubeconfig=${KubeDir}/${USER}.yaml config use-context ${USER}@${KubeConfigCluster}
kubectl --kubeconfig=${KubeDir}/${USER}.yaml config view

5. 创建token来访问apiserver

以上方式是通过创建ServiceAccount的Secret的方式来获取token，该token是永久生效的，如果要使token失效可以删除对应的Secret对象，

如果要使用指定过期期限的token权限，可以通过以下命令生成：

# 生成过期时间365天的token
TOKEN=$(kubectl -n ${NAMESPACE} create token ${USER} --duration 8760h)
kubectl --kubeconfig=${KubeDir}/${USER}.yaml config set-credentials ${USER} --token=${TOKEN}

参考：

如何将 Kubeconfig 中的证书文件转为证书数据 - CODING 帮助中心

Feedback

Was this page helpful?

Glad to hear it! Please tell us how we can improve.

Sorry to hear that. Please tell us how we can improve.

最后修改 December 18, 2024: create kubeconfig (9e7ff3d)