K8s对于存储解耦的设计是，pv交给存储管理员来管理，我们只管用pvc来消费就好，但这里我们实际还是得一起管理pv和pvc，在实际工作中，我们（存储管理员）可以提前配置好pv的动态供给StorageClass，来根据pvc的消费动态生成pv。
    利用nfs-client-provisioner来生成一个基于nfs的StorageClass，部署配置yaml配置如下，保持为nfs-sc.yaml：

    1. cat nfs-sc.yaml
    3. apiVersion: v1
    4. kind: ServiceAccount
    5. metadata:
    6.   name: nfs-client-provisioner
    7.   namespace: kube-system
    9. ---
    10. kind: ClusterRole
    11. apiVersion: rbac.authorization.k8s.io/v1
    12. metadata:
    13.   name: nfs-client-provisioner-runner
    14. rules:
    15.   - apiGroups: [""]
    16.     resources: ["persistentvolumes"]
    17.     verbs: ["get", "list", "watch", "create", "delete"]
    18.   - apiGroups: [""]
    19.     resources: ["persistentvolumeclaims"]
    20.     verbs: ["get", "list", "watch", "update"]
    21.   - apiGroups: ["storage.k8s.io"]
    22.     resources: ["storageclasses"]
    23.     verbs: ["get", "list", "watch"]
    24.   - apiGroups: [""]
    25.     resources: ["events"]
    26.     verbs: ["list", "watch", "create", "update", "patch"]
    27.   - apiGroups: [""]
    28.     resources: ["endpoints"]
    29.     verbs: ["get", "list", "watch", "create", "update", "patch"]
    31. ---
    32. kind: ClusterRoleBinding
    33. apiVersion: rbac.authorization.k8s.io/v1
    34. metadata:
    35.   name: run-nfs-client-provisioner
    36. subjects:
    37.   - kind: ServiceAccount
    38.     name: nfs-client-provisioner
    39.     namespace: kube-system 
    40. roleRef:
    41.   kind: ClusterRole
    42.   name: nfs-client-provisioner-runner
    43.   apiGroup: rbac.authorization.k8s.io
    45. ---
    46. kind: Deployment
    47. apiVersion: apps/v1
    48. metadata:
    49.   name: nfs-provisioner-01
    50.   namespace: kube-system
    51. spec:
    52.   replicas: 1
    53.   strategy:
    54.     type: Recreate
    55.   selector:
    56.     matchLabels:
    57.       app: nfs-provisioner-01
    58.   template:
    59.     metadata:
    60.       labels:
    61.         app: nfs-provisioner-01
    62.     spec:
    63.       serviceAccountName: nfs-client-provisioner
    64.       containers:
    65.         - name: nfs-client-provisioner
    66.           image: jmgao1983/nfs-client-provisioner:latest
    67.           imagePullPolicy: IfNotPresent
    68.           volumeMounts:
    69.             - name: nfs-client-root
    70.               mountPath: /persistentvolumes
    71.           env:
    72.             - name: PROVISIONER_NAME
    73.               value: nfs-provisioner-01  # 此处供应者名字供storageclass调用
    74.             - name: NFS_SERVER
    75.               value: 10.0.1.201   # 填入NFS的地址
    76.             - name: NFS_PATH
    77.               value: /nfs_dir   # 填入NFS挂载的目录
    78.       volumes:
    79.         - name: nfs-client-root
    80.           nfs:
    81.             server: 10.0.1.201   # 填入NFS的地址
    82.             path: /nfs_dir   # 填入NFS挂载的目录
    84. ---
    85. apiVersion: storage.k8s.io/v1
    86. kind: StorageClass
    87. metadata:
    88.   name: nfs-boge
    89. provisioner: nfs-provisioner-01
    90. # Supported policies: Delete、 Retain ， default is Delete
    91. reclaimPolicy: Retain

    开始创建这个StorageClass：

    1. # kubectl apply -f nfs-sc.yaml 
    2. serviceaccount/nfs-client-provisioner created
    3. clusterrole.rbac.authorization.k8s.io/nfs-client-provisioner-runner created
    4. clusterrolebinding.rbac.authorization.k8s.io/run-nfs-client-provisioner created
    5. deployment.apps/nfs-provisioner-01 created
    6.   orageclass.storage.k8s.io/nfs-boge created
    8. # 注意这个是在放kube-system的namespace下面，这里面放置一些偏系统类的服务
    9. # kubectl -n kube-system get pod -w
    10. NAME                                       READY   STATUS              RESTARTS   AGE
    11. calico-kube-controllers-7fdc86d8ff-dpdm5   1/1     Running             1          24h
    12. calico-node-8jcp5                          1/1     Running             1          24h
    13. calico-node-m92rn                          1/1     Running             1          24h
    14. calico-node-xg5n4                          1/1     Running             1          24h
    15. calico-node-xrfqq                          1/1     Running             1          24h
    16. coredns-d9b6857b5-5zwgf                    1/1     Running             1          24h
    17. metrics-server-869ffc99cd-wfj44            1/1     Running             2          24h
    18. nfs-provisioner-01-5db96d9cc9-qxlgk        0/1     ContainerCreating   0          9s
    19. nfs-provisioner-01-5db96d9cc9-qxlgk        1/1     Running             0          21s
    21. # StorageClass已经创建好了
    22. # kubectl get sc
    23. NAME       PROVISIONER          RECLAIMPOLICY   VOLUMEBINDINGMODE   ALLOWVOLUMEEXPANSION   AGE
    24. nfs-boge   nfs-provisioner-01   Retain          Immediate           false                  37s

    我们来基于StorageClass创建一个pvc，看看动态生成的pv是什么效果：

    # vim pvc-sc.yaml 
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: pvc-sc
spec:
  storageClassName: nfs-boge
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 1Mi

# kubectl  apply -f pvc-sc.yaml 
persistentvolumeclaim/pvc-sc created

# kubectl  get pvc
NAME     STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
pvc-sc   Bound    pvc-63eee4c7-90fd-4c7e-abf9-d803c3204623   1Mi        RWX            nfs-boge       3s
pvc1     Bound    pv1                                        1Gi        RWO            nfs            24m

# kubectl  get pv
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM            STORAGECLASS   REASON   AGE
pv1                                        1Gi        RWO            Recycle          Bound    default/pvc1     nfs                     49m
pvc-63eee4c7-90fd-4c7e-abf9-d803c3204623   1Mi        RWX            Retain

    我们修改下nginx的yaml配置，将pvc的名称换成上面的pvc-sc：

    # vim nginx.yaml 
---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: nginx
  name: nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx
        name: nginx
        volumeMounts:    # 我们这里将nginx容器默认的页面目录挂载
          - name: html-files
            mountPath: "/usr/share/nginx/html"
      volumes:
        - name: html-files
          persistentVolumeClaim:
            claimName: pvc-sc


# kubectl apply -f nginx.yaml 
service/nginx unchanged
deployment.apps/nginx configured

# 这里注意下，因为是动态生成的pv，所以它的目录基于是一串随机字符串生成的，这时我们直接进到pod内来创建访问页面
# kubectl exec -it nginx-57cdc6d9b4-n497g -- bash
root@nginx-57cdc6d9b4-n497g:/# echo 'storageClass used' > /usr/share/nginx/html/index.html
root@nginx-57cdc6d9b4-n497g:/# exit

# curl 10.68.238.54                              
storageClass used

# 我们看下NFS挂载的目录
# ll /nfs_dir/
total 0
drwxrwxrwx 2 root root 24 Nov 27 17:52 default-pvc-sc-pvc-63eee4c7-90fd-4c7e-abf9-d803c3204623
drwxr-xr-x 2 root root  6 Nov 27 17:25 pv1