為Kubernetes dashboard訪問使用者新增許可權控制

[TOC]

1. 需求

在開發環境給開發人員建立應用部署管理許可權，可以使用dashboard的token和kubeconfig檔案登入，並在開發人員機器上安裝kubectl命令，可以使用kubectl port-forward命令。

2. 方案

因為我們用到了dashboard和kubeapps，所以他們的rbac許可權都要分配。
建立namespace：dev
建立ServiceAccount：dev-user1
給相應許可權，並繫結ServiceAccount。

3. 實現

3.1 分配dashboard許可權

kubectl apply -f dev-user1.yaml

---
# ServiceAccount
apiVersion: v1
kind: ServiceAccount
metadata:
  name: dev-user1
  namespace: dev

---
# role
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  namespace: dev
  name: role-dev-user1
rules:
- apiGroups: [""]
  resources: ["pods"]
  verbs: ["get", "list", "watch", "delete", "update", "patch"]
- apiGroups: [""]
  resources: ["pods/portforward", "pods/proxy"]
  verbs: ["get", "list", "watch", "create", "update", "patch", "delete"]
- apiGroups: [""]
  resources: ["pods/log"]
  verbs: ["get", "list", "watch", "delete"]
- apiGroups: ["extensions", "apps"]
  resources: ["deployments"]
  verbs: ["get", "list", "watch", "create", "update", "patch", "delete"]
- apiGroups: [""]
  resources: ["namespaces"]
  verbs: ["get", "watch", "list"]
- apiGroups: [""]
  resources: ["events"]
  verbs: ["get", "watch", "list"]
- apiGroups: ["apps", "extensions"]
  resources: ["replicasets"]
  verbs: ["get", "watch", "list", "create", "update", "pathch", "delete"]
- apiGroups: [""]
  resources: ["configmaps"]
  verbs: ["get", "watch", "list", "create", "update", "pathch", "delete"]
- apiGroups: [""]
  resources: ["persistentvolumeclaims"]
  verbs: ["get", "watch", "list"]
- apiGroups: [""]
  resources: ["secrets"]
  verbs: ["get", "watch", "list"]
- apiGroups: [""]
  resources: ["services"]
  verbs: ["get", "watch", "list", "create", "update", "pathch", "delete"]
- apiGroups: ["extensions"]
  resources: ["ingresses"]
  verbs: ["get", "watch", "list"]
- apiGroups: ["apps"]
  resources: ["daemonsets"]
  verbs: ["get", "watch", "list"]
- apiGroups: ["batch"]
  resources: ["jobs"]
  verbs: ["get", "watch", "list"]
- apiGroups: ["batch"]
  resources: ["cronjobs"]
  verbs: ["get", "watch", "list"]
- apiGroups: [""]
  resources: ["replicationcontrollers"]
  verbs: ["get", "watch", "list"]
- apiGroups: ["apps"]
  resources: ["statefulsets"]
  verbs: ["get", "watch", "list"]
- apiGroups: [""]
  resources: ["endpoints"]
  verbs: ["get", "watch", "list"]

---
# role bind
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: role-bind-dev-user1
  namespace: dev
subjects:
- kind: ServiceAccount
  name: dev-user1
  namespace: dev
roleRef:
  kind: Role
  name: role-dev-user1
  apiGroup: rbac.authorization.k8s.io

#---
## clusterrole
#kind: ClusterRole
#apiVersion: rbac.authorization.k8s.io/v1
#metadata:
#  namespace: dev
#  name: clusterrole-dev-user1
#rules:
#- apiGroups: [""]
#  resources: ["namespaces"]
#  verbs: ["get", "watch", "list"]
#
#---
## clusterrole bind
#kind: ClusterRoleBinding
#apiVersion: rbac.authorization.k8s.io/v1
#metadata:
#  name: clusterrole-bind-dev-user1
#  namespace: dev
#subjects:
#- kind: ServiceAccount
#  name: dev-user1
#  namespace: dev
#roleRef:
#  kind: ClusterRole
#  name: clusterrole-dev-user1
#  apiGroup: rbac.authorization.k8s.io
 

3.2 分配kubeapps許可權

kubectl apply -f https://raw.githubusercontent.com/kubeapps/kubeapps/master/docs/user/manifests/kubeapps-applications-read.yaml
kubectl create -n dev rolebinding dev-user1-view \
  --clusterrole=kubeapps-applications-read \
  --serviceaccount dev:dev-user1

export KUBEAPPS_NAMESPACE=kubeapps
kubectl apply -n $KUBEAPPS_NAMESPACE -f https://raw.githubusercontent.com/kubeapps/kubeapps/master/docs/user/manifests/kubeapps-repositories-read.yaml
kubectl create -n dev rolebinding dev-user1-edit \
  --clusterrole=edit \
  --serviceaccount dev:dev-user1
kubectl create -n $KUBEAPPS_NAMESPACE rolebinding dev1-user1-kubeapps-repositories-read \
  --role=kubeapps-repositories-read \
  --serviceaccount dev:dev-user1
 

token獲取：

kubectl get -n dev secret $(kubectl get -n dev serviceaccount dev-user1 -o jsonpath='{.secrets[].name}') -o jsonpath='{.data.token}' | base64 --decode

3.3 生成kubeconfig

通過token方式訪問kube-apiserver

# 建立 kubectl config 檔案
# 設定叢集引數
kubectl config set-cluster kubernetes \
  --insecure-skip-tls-verify=true \
  --server="https://192.168.105.99:8443"
# 設定客戶端認證引數
kubectl config set-credentials dev-user1 \
  --token='上文中獲取到的token' 
# 設定上下文引數
kubectl config set-context kubernetes \
  --cluster=kubernetes \
  --user=dev-user1  \
  --namespace=dev 
# 設定預設上下文
kubectl config use-context kubernetes

注意
配置kubeconfig時指定路徑，以免覆蓋已有配置，--kubeconfig=configpath

也可以直接建立檔案config，修改內容即可。

apiVersion: v1
clusters:
- cluster:
    insecure-skip-tls-verify: true
    server: https://192.168.105.99:8443
  name: kubernetes
contexts:
- context:
    cluster: kubernetes
    namespace: dev
    user: dev-user1
  name: kubernetes
current-context: kubernetes
kind: Config
preferences: {}
users:
- name: dev-user1
  user:
    token: eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJkZXYiLCJrdWJlcm5ldGVzLmlvL3NlcnZpY2VhY2NvdW50L3NlY3JldC5uYW1lIjoiZGV2LXVzZXIxLXRva2VuLTJsbDlnIiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9zZX291bnQubmFtZSI6ImRldi11c2VyMSIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50LnVpZCI6IjdiY2Q4N2E1LWM0NGEtMTFlOC1iY2I5LTAwMGMyOWVhM2UzMCIsInN1YiI6InN5c3RlbTpzZXJ2aWNlYWNjb3VudDpkZXY6ZGV2LXVzZXIxIn0.1M84CPHY-GoyeaRFyBcD49GTwG5o0HMhN8lVsH9GDiqdui-1ppyi3JMONRJ9aWdswEF7-wsb5d4MQEk-9z5yiVh2r8SMP0EhcUR5ierntzD1bwwwuYzDxE4vHAuPB1tTxM0fOL3H-BOjt68iBKmOtRJumx8LzSUleQiNBBqR1B_yRLqrO6yslw44WC432O5g1v

4. 測試驗證

windows kubectl命令安裝

命令下載：
https://storage.googleapis.com/kubernetes-release/release/v1.12.0/bin/windows/amd64/kubectl.exe

然後將其放至系統PATH目錄下，比如c:\Windows
命令使用時，可使用cmd、powershell或者其它命令提示行工具。推薦使用Git Bash，因為安裝過Git，則安裝了此工具。

kubeconfig檔案
kubeconfig檔案，即上檔案中生成的config檔案。
檔名為config，檔案放到 ~/.kube/下（~為使用者家目錄），因為kubectl命令預設讀取此檔案，否則每次使用kubectl命令，需要用引數--kubeconfig=configpath指定。

kubectl get pod -n dev
kubectl port-forward svc/dev-mysql-mysqlha 3306:3306 -n dev

參考資料：
[1] https://kubernetes.io/docs/reference/access-authn-authz/rbac/
[2] https://blog.qikqiak.com/post/add-authorization-for-kubernetes-dashboard/
[3] https://github.com/kubeapps/kubeapps/blob/master/docs/user/access-control.md
[4] https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#config
[5] https://kubernetes.io/docs/tasks/tools/install-kubectl/#configure-kubectl