创建nfs服务，并在K8s中挂载为SC

（storeageclass设为默认）

一、在Ubuntu搭建nfs服务器

1、安装nfs服务器

sudo apt install nfs-kernel-server

2、创建nfs服务器共享目录

创建一个目录用于nfs服务器将文件共享给客户端，这个目录将会写入到nfs配置文件中：

mkdir /data/nfs-demo

3、修改nfs服务器配置文件

打开nfs服务器配置文件/etc/exports，指定nfs服务器共享目录及其属性，内容如下：

/data/nfs-demo  *(rw,sync,no_root_squash)

......
/data/nfs-demo：指定/nfsroot为nfs服务器的共享目录
*：允许所有的网段访问，也可以使用具体的IP
rw：挂接此目录的客户端对该共享目录具有读写权限
sync：资料同步写入内存和硬盘
no_root_squash：root用户具有对根目录的完全管理访问权限
no_subtree_check：不检查父目录的权限
......

4、重启nfs服务器

sudo service nfs-kernel-server restart
或者
sudo /etc/init.d/nfs-kernel-server restart

到此，Ubuntu安装nfs服务器的过程就完成了，可以执行下面这个命令查看nfs服务器的共享目录：

showmount -e localhost

在10.101.17.11上挂载该目录

sudo mount -t nfs 10.101.17.13:/data/nfs-demo /data/nfs-demo

二、k8s基于nfs创建storageclass

创建命名空间

kubectl create namespace nfs

1、使用以下文档配置account及相关权限

rbac.yaml: #唯一需要修改的地方只有namespace,根据实际情况定义

apiVersion: v1
kind: ServiceAccount
metadata:
  name: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: nfs        #根据实际环境设定namespace,下面类同
---
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: nfs
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: nfs
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
  namespace: nfs
subjects:
  - kind: ServiceAccount
    name: nfs-client-provisioner
    # replace with namespace where provisioner is deployed
    namespace: nfs
roleRef:
  kind: Role
  name: leader-locking-nfs-client-provisioner
  apiGroup: rbac.authorization.k8s.io

2、创建NFS provisioner

nfs-provisioner.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nfs-client-provisioner
  labels:
    app: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: nfs #与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: nfs-storage  #provisioner名称,请确保该名称与 nfs-StorageClass.yaml文件中的provisioner名称保持一致
            - name: NFS_SERVER
              value: 10.101.17.13   #NFS Server IP地址
            - name: NFS_PATH  
              value: /data/nfs-demo    #NFS挂载卷
      volumes:
        - name: nfs-client-root
          nfs:
            server: 10.101.17.13  #NFS Server IP地址
            path: /data/nfs-demo     #NFS 挂载卷

3、创建NFS资源的StorageClass

nfs-StorageClass.yaml

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: managed-nfs-storage
provisioner: nfs-storage #这里的名称要和provisioner配置文件中的环境变量PROVISIONER_NAME保持一致parameters:  archiveOnDelete: "false"

4、执行命令

kubectl apply -f rbac.yaml
kubectl apply -f nfs-provisioner.yaml
kubectl apply -f nfs-StorageClass.yaml

三、配置默认 StorageClass

列出集群中的 StorageClass

kubectl get storageclass

标记默认 StorageClass 非默认：

kubectl patch storageclass openebs-hostpath -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"false"}}}'

标记一个 StorageClass 为默认：

kubectl patch storageclass managed-nfs-storage -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"true"}}}'

四、测试

测试pvc
test-claim.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: 1Mi

kubectl create -f test-claim.yaml
kubectl get pvc
......
NAME         STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS          AGE
test-claim   Bound    pvc-40afffdb-13e1-429a-bf15-6798487694a8   1Mi        RWX            managed-nfs-storage   5s

遇见如下情况，发现pvc的状态一直是pending，说明没有创建pv，也未能与pv进行绑定
.......
NAME         STATUS    VOLUME   CAPACITY   ACCESS MODES   STORAGECLASS          AGE
test-claim   Pending                                      managed-nfs-storage   9s
.......


1、通过kubectl describe命令查看错误提示信息，
信息中有：waiting for a volume to be created, either by external provisioner “nfs-storage” or manually created by system administrator
2、通过kubectl logs命令查看pod（nfs-client-provisioner）日志，
日志中有：unexpected error getting claim reference: selfLink was empty, can’t make reference。
3、使用第二步骤的信息去网上查找，按照链接中的步骤解决该问题https://blog.csdn.net/qq_41793064/article/details/123111934

测试pod
test-pod.yaml

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

kubectl create -f test-pod.yaml
kubectl get pods 
NAME       READY   STATUS    RESTARTS   AGE
test-pod   0/1     Pending   0          9s

清除环境

kubectl delete -f test-pod.yaml
kubectl delete -f test-claim.yaml