【K8s存储】使用外部制备器创建NFS存储类说明

参考：
https://github.com/kubernetes-sigs/nfs-subdir-external-provisioner

部署清单

RBAC清单

apiVersion: v1
kind: ServiceAccount
metadata:
  name: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: default
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: nfs-client-provisioner-runner
rules:
  - apiGroups: [""]
    resources: ["nodes"]
    verbs: ["get", "list", "watch"]
  - 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
  # replace with namespace where provisioner is deployed
  namespace: default
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

Deployment清单

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nfs-client-provisioner
  labels:
    app: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: default
spec:
  replicas: 1
  strategy:
    type: Recreate  ## 更新策略为删除再创建
  selector:
    matchLabels:
      app: nfs-client-provisioner
  template:
    metadata:
      labels:
        app: nfs-client-provisioner
    spec:
      serviceAccountName: nfs-client-provisioner
      containers:
        - name: nfs-client-provisioner
          image: k8s.gcr.io/sig-storage/nfs-subdir-external-provisioner:v4.0.2  ## 实际中可以使用阿里云海外构建所需镜像
          volumeMounts:
            - name: nfs-client-root
              mountPath: /persistentvolumes
          env:
            - name: PROVISIONER_NAME
              value: k8s-sigs.io/nfs-subdir-external-provisioner  ## 后面存储类的provisioner值要和这个保持一致
            - name: NFS_SERVER
              value: 10.3.243.101  ## 必须和volumes设置保持一致
            - name: NFS_PATH
              value: /ifs/kubernetes  ## 必须和volumes设置保持一致
      volumes:
        - name: nfs-client-root
          nfs:
            server: 10.3.243.101
            path: /ifs/kubernetes

StorageClass清单

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: managed-nfs-storage
  annotations:
    storageclass.kubernetes.io/is-default-class: "false"  ## 是否设置为默认的存储类
provisioner: k8s-sigs.io/nfs-subdir-external-provisioner  ## 必须匹配deployment中环境变量PROVISIONER_NAME的值
parameters:
  archiveOnDelete: "false"
mountOptions: 
  - hard
  - nfsvers=4

parameters说明：

• onDelete：如果存在且有delete值，则删除该目录，如果存在且有retain值，则保留该目录。默认将在共享上以此名称归档：archived-<volume.Name>
• archiveOnDelete：如果它存在并且值为false，则删除该目录。 如果 onDelete 存在，archiveOnDelete 将被忽略。默认将在共享上以此名称归档：archived-<volume.Name>
• pathPattern：指定用于通过 PVC 元数据（例如标签、注释、名称或命名空间）创建目录路径的模板。 要指定元数据，请使用 ${.PVC.}。 示例：如果文件夹应命名为 -，则使用 ${.PVC.namespace}-${.PVC.name} 作为 pathPattern。 默认不适用。

简单测试

特别注意：必须在集群所有节点安装nfs-common。

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: test-claim
spec:
  storageClassName: managed-nfs-storage  ## 设置上面创建的存储类
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 1Mi
---
kind: Pod
apiVersion: v1
metadata:
  name: test-pod
spec:
  containers:
  - name: test-pod
    image: gcr.io/google_containers/busybox:1.24
    command:
      - "/bin/sh"
    args:
      - "-c"
      - "touch /mnt/SUCCESS && exit 0 || exit 1"
    volumeMounts:
      - name: nfs-pvc
        mountPath: "/mnt"
  restartPolicy: "Never"
  volumes:
    - name: nfs-pvc
      persistentVolumeClaim:
        claimName: test-claim  ## 设置上面创建的PVC

局限性

• 不保证配置的存储。 您可以分配超过 NFS 共享的总大小。 共享也可能没有足够的存储空间来实际容纳请求。
• 未实施预配的存储限制。 无论供应的大小如何，应用程序都可以扩展以使用所有可用存储。
• 目前不支持任何形式的存储调整大小/扩展操作。 您最终将处于此错误状态： Ignoring the PVC: didn't find a plugin capable of expanding the volume; waiting for an external controller to process this PVC.