K8S storageclass

一、簡介

要使用 StorageClass，就得安裝對應的自動配置程序，比如這里存儲后端使用的是 nfs，那么就需要使用到一個 nfs-client 的自動配置程序，也叫它 Provisioner，這個程序使用我們已經配置好的 nfs 服務器，來自動創建持久卷，也就是自動創建 PV。

• 自動創建的 PV 以${namespace}-${pvcName}-${pvName}這樣的命名格式創建在 NFS 服務器上的共享數據目錄中

二、測試storageclass效果

1、rbac.yaml

[root@k8s-master storage]# cat rbac.yaml 
apiVersion: v1
kind: ServiceAccount
metadata:
  name: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: default        #根據實際環境設定namespace,下面類同
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: nfs-client-provisioner-runner
rules:
  - apiGroups: [""]
    resources: ["persistentvolumes"]
    verbs: ["get", "list", "watch", "create", "delete"]
  - apiGroups: [""]
    resources: ["persistentvolumeclaims"]
    verbs: ["get", "list", "watch", "update"]
  - apiGroups: ["storage.k8s.io"]
    resources: ["storageclasses"]
    verbs: ["get", "list", "watch"]
  - apiGroups: [""]
    resources: ["events"]
    verbs: ["create", "update", "patch"]
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: run-nfs-client-provisioner
subjects:
  - kind: ServiceAccount
    name: nfs-client-provisioner
    # replace with namespace where provisioner is deployed
    namespace: default
roleRef:
  kind: ClusterRole
  name: nfs-client-provisioner-runner
  apiGroup: rbac.authorization.k8s.io
---
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: leader-locking-nfs-client-provisioner
    # replace with namespace where provisioner is deployed
  namespace: default
rules:
  - apiGroups: [""]
    resources: ["endpoints"]
    verbs: ["get", "list", "watch", "create", "update", "patch"]
---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: leader-locking-nfs-client-provisioner
subjects:
  - kind: ServiceAccount
    name: nfs-client-provisioner
    # replace with namespace where provisioner is deployed
    namespace: default
roleRef:
  kind: Role
  name: leader-locking-nfs-client-provisioner
  apiGroup: rbac.authorization.k8s.io

2、創建provisioner.yaml

[root@k8s-master storage]# cat prvisor-deployment.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nfs-client-provisioner
  labels:
    app: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: default  #與RBAC文件中的namespace保持一致
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nfs-client-provisioner
  strategy:
    type: Recreate
  selector:
    matchLabels:
      app: nfs-client-provisioner
  template:
    metadata:
      labels:
        app: nfs-client-provisioner
    spec:
      serviceAccountName: nfs-client-provisioner
      containers:
        - name: nfs-client-provisioner
          image: quay.io/external_storage/nfs-client-provisioner:latest
          volumeMounts:
            - name: nfs-client-root
              mountPath: /persistentvolumes
          env:
            - name: PROVISIONER_NAME
              value: wuchang-nfs-storage  #provisioner名稱,請確保該名稱與 nfs-StorageClass.yaml文件中的provisioner名稱保持一致
            - name: NFS_SERVER
              value: 192.168.48.250   #NFS Server IP地址
            - name: NFS_PATH  
              value: /nfsdata    #NFS掛載卷
      volumes:
        - name: nfs-client-root
          nfs:
            server: 192.168.48.250  #NFS Server IP地址
            path: /nfsdata     #NFS 掛載卷

3、准備工作好了之后創建storageclass.yaml

[root@k8s-master storage]# cat storageclass.yaml 
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: managed-nfs-storage
provisioner: wuchang-nfs-storage #這里的名稱要和provisioner配置文件中的環境變量PROVISIONER_NAME保持一致
parameters:
  archiveOnDelete: "false"

4、創建測試的pvc，pvc-test

[root@k8s-master storage]# cat test-pvc.yaml 
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: test-claim
  annotations:
    volume.beta.kubernetes.io/storage-class: "managed-nfs-storage"   #與nfs-StorageClass.yaml metadata.name保持一致
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 1Mi

5、創建測試的pod，test-pd

[root@k8s-master storage]# cat pod-demo.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: test-pd
spec:
  containers:
  - image: ikubernetes/myapp:v1
    name: test-container
    volumeMounts:
    - mountPath: /test-pd
      name: nfs-pvc
  volumes:
    - name: nfs-pvc
      persistentVolumeClaim:
        claimName: test-claim  #與PVC名稱保持一致

6、進入test-pd進行訪問，創建文件wuchang

[root@k8s-master storage]# kubectl exec -it test-pd /bin/sh
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
/ # ls
bin      dev      etc      home     lib      media    mnt      proc     root     run      sbin     srv      sys      test-pd  tmp      usr      var
/ # cd test-pd/
/test-pd # ls
SUCCESS  hello
/test-pd # touch wuchang
/test-pd # ls
SUCCESS  hello    wuchang
/test-pd # 

7、在nfs服務器上查看文件

二、在statefulset上測試文件storageclass

1、創建stateful-nginx.yaml 

[root@k8s-master storage]# cat stateful-nginx.yaml 
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: nfs-web
spec:
  selector:
    matchLabels:
      app: nfs-web
  serviceName: "nginx"
  replicas: 2
  template:
    metadata:
      labels:
        app: nfs-web
    spec:
      terminationGracePeriodSeconds: 10
      containers:
      - name: nginx
        image: nginx:1.7.9
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80
          name: web
        volumeMounts:
        - name: www
          mountPath: /usr/share/nginx/html
  volumeClaimTemplates:
  - metadata:
      name: www
      annotations:
        volume.beta.kubernetes.io/storage-class: managed-nfs-storage   //指明storageclass的名稱
    spec:
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 1Gi

2、已經自動創建兩個大小為1G的PV和PVC

3、查看nfs服務器，存在兩個新的文件夾，格式為${namespace}-${pvcName}-${pvName}