使用 nfs 作为kubernetes动态 storageClass 存储

1、StorageClass介绍

参考网址：https://github.com/kubernetes-retired/external-storage

​ https://blog.51cto.com/xuexinhuan/5394844

StorageClass对象会定义下面两部分内容:

1: PV的属性.比如,存储类型,Volume的大小等
2: 创建这种PV需要用到的存储插件
有了这两个信息之后，Kubernetes 就能够根据用户提交的 PVC，找到一个对应的 StorageClass，之后Kubernetes 就会调用该 StorageClass 声明的存储插件，进而创建出需要的 PV。

但是其实使用起来是一件很简单的事情,你只需要根据自己的需求，编写YAML文件即可，然后使用kubectl create命令执行即可。

创建StorageClass流程

• 创建一个可用的 NFS Serve
• 创建 Service Account. 这是用来管控 NFS provisioner 在k8s集群中运行的权限
• 创建 StorageClass. 负责建立PVC并调用 NFS provisioner 进行预定的工作, 并让 PV 与 PVC 建立管理
• 创建 NFS provisioner. 有两个功能,一个是在 NFS 共享目录下创建挂载点(volume), 另一个则是建了 PV 并将 PV 与 NFS 的挂载点建立关联

2、安装配置 NFS Serve

安装：

yum install -y nfs-utils
mkdir /data/nfs-volume
chmod 755 /data/nfs-volume
#chown nfsnobody:nfsnobody /data/nfs-volume
echo "/data/nfs-volume    192.168.1.0/24(rw,sync,all_squash)" > /etc/exports
systemctl enable nfs
systemctl start nfs

验证共享存储是否生效：

showmount -e

3、创建account及相关权限

创建external_storage命名空间

kubectl create ns external-storage

创建RBAC权限，nfs-client-rbac.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: external-storage
---
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: external-storage
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: external-storage
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: external-storage
subjects:
  - kind: ServiceAccount
    name: nfs-client-provisioner
    # replace with namespace where provisioner is deployed
    namespace: external-storage
roleRef:
  kind: Role
  name: leader-locking-nfs-client-provisioner
  apiGroup: rbac.authorization.k8s.io

创建基于NFS资源的StorageClass

nfs-client-class.yaml

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: managed-nfs-storage
provisioner: fuseim.pri/ifs # or choose another name, must match deployment's env PROVISIONER_NAME'
parameters:
  archiveOnDelete: "false"

创建NFS provisioner Deployment

nfs-client-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: external-storage
spec:
  replicas: 1
  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: registry.cn-beijing.aliyuncs.com/mydlq/nfs-subdir-external-provisioner:v4.0.0
          volumeMounts:
            - name: nfs-client-root
              mountPath: /persistentvolumes
          env:
            - name: PROVISIONER_NAME
              value: fuseim.pri/ifs
            - name: NFS_SERVER
              value: 192.168.1.66
            - name: NFS_PATH
              value: /data/nfs-volume
      volumes:
        - name: nfs-client-root
          nfs:
            server: 192.168.1.66
            path: /data/nfs-volume

依次应用资源配置清单：

kubectl apply -f nfs-client-rbac.yaml
kubectl apply -f nfs-client-class.yaml
kubectl apply -f nfs-client-deployment.yaml

4、创建PVC，POD验证

创建pvc，并验证：

nfs-client-pvc-test.yaml

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: test-claim
  annotations:
    volume.beta.kubernetes.io/storage-class: "managed-nfs-storage"
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 100Mi

如图所示：

创建测试pod,查看是否可以正常挂载

nfs-client-pod-test.yaml

kind: Pod
apiVersion: v1
metadata:
  name: test-pod
spec:
  containers:
  - name: test-pod
    image: busybox:1.36.0
    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

验证：在nfs服务器验证