1. 概述

在日常学习与企业内网环境中，可能并没有条件使用Ceph等分布式存储，这时可以使用NFS作为StorageClass。

NFS代表网络文件系统（Network File System），它是一种允许计算机通过网络共享文件和存储设备的协议。

2. 环境说明

本文nfs server所在服务器的操作系统为Ubuntu 22.04.2, IP为192.168.3.10

kubernetes版本为1.27.2
kubernetes节点的操作系统为RockyLinux 9.2 x64

3. k8s集群外部署NFS server

1. 安装nfs server

apt install -y nfs-kernel-server 

2. 配置nfs server

mkdir /data/nfs
chmod a+rw /data/nfs/
echo '/data/nfs *(rw,sync,no_subtree_check,no_root_squash,insecure)' >> /etc/exports
# 使配置生效
exportfs -r
# 查看当前配置
exportfs

systemctl restart rpcbind
systemctl enable rpcbind
systemctl restart nfs-server
systemctl enable nfs-server

# 查看rpc服务的注册情况
rpcinfo -p localhost |grep nfs
showmount -e 192.168.3.10

4. k8s集群内创建Storage class

官方文档: https://github.com/kubernetes-sigs/nfs-subdir-external-provisioner

4.1 所有k8s节点安装nfs client

# centos/rockylinux
yum install -y nfs-utils

4.2 为NFS设置rbac

创建文件rbac.yaml

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

kubectl apply -f rbac.yaml

输出

serviceaccount/nfs-client-provisioner created
clusterrole.rbac.authorization.k8s.io/nfs-client-provisioner-runner created
clusterrolebinding.rbac.authorization.k8s.io/run-nfs-client-provisioner created
role.rbac.authorization.k8s.io/leader-locking-nfs-client-provisioner created
rolebinding.rbac.authorization.k8s.io/leader-locking-nfs-client-provisioner created

4.3 创建nfs subdir external provisioner

创建文件nfs-subdir-external-provisioner.yaml

kind: Deployment
apiVersion: apps/v1
metadata:
  name: nfs-client-provisioner
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nfs-client-provisioner
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: nfs-client-provisioner
    spec:
      serviceAccountName: nfs-client-provisioner
      containers:
        - name: nfs-client-provisioner
          # image: registry.k8s.io/sig-storage/nfs-subdir-external-provisioner:v4.0.2
          image: k8s.dockerproxy.com/sig-storage/nfs-subdir-external-provisioner:v4.0.2
          volumeMounts:
            - name: nfs-client-root
              mountPath: /persistentvolumes
          env:
            - name: PROVISIONER_NAME
              value: k8s-sigs.io/nfs-subdir-external-provisioner
            - name: NFS_SERVER
              # value: <YOUR NFS SERVER HOSTNAME>
              value: 192.168.3.10
            - name: NFS_PATH
              # value: /var/nfs
              value: /data/nfs
      volumes:
        - name: nfs-client-root
          nfs:
            # server: <YOUR NFS SERVER HOSTNAME>
            server: 192.168.3.10
            path: /data/nfs

kubectl apply -f nfs-subdir-external-provisioner.yaml

4.4 部署storage class

创建文件nfs-storage-class.yaml

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: nfs-client
provisioner: k8s-sigs.io/nfs-subdir-external-provisioner # or choose another name, must match deployment's env PROVISIONER_NAME'
parameters:
  pathPattern: "${.PVC.namespace}/${.PVC.annotations.nfs.io/storage-path}" # 此处也可以使用 "${.PVC.namespace}/${.PVC.name}" 来使用pvc的名称作为nfs中真实目录名称
  onDelete: delete

kubectl apply -f nfs-storage-class.yaml

5. 测试nfs storage class

5.1 创建一个PVC

创建文件nfs-pvc.yaml

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: test-claim
  annotations:
    nfs.io/storage-path: "test-path" # not required, depending on whether this annotation was shown in the storage class description
spec:
  storageClassName: nfs-client
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 50Mi

kubectl apply -f nfs-pvc.yaml

查看pvc

kubectl get pvc

输出

NAME         STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
test-claim   Bound    pvc-e9a9f6ad-45f8-4e3f-9b1e-abdc5f59c7ef   50Mi       RWX            nfs-client     11s

5.2 在NFS server查看

登录服务器192.168.3.10

可以看到在/data/nfs/目录下有一个default目录,这表示default命名空间

default目录下有一个test-path目录，这个就是创建pvc时在annotations指定的 nfs.io/storage-path: "test-path"；

tree /data/nfs/

/data/nfs/
├── default
│   └── test-path