k8s-数据卷NFS共享卷

1. k8s数据卷NFS共享卷

• NFS数据卷：提供对NFS挂载支持，可以自动将NFS共享路径挂载到Pod中

• NFS：是一个主流的文件共享服务器。

• 安装示例：

  # yum install nfs-utils -y
  # vi /etc/exports
  /ifs/kubernetes *(rw,no_root_squash)
  # mkdir -p /ifs/kubernetes
  # systemctl start nfs
  # systemctl enable nfs
  

  注：每个Node上都要安装nfs-utils包

• NFS共享卷架构图
  

• 示例：将网站程序通过NFS数据卷共享，让所有Pod使用

• 示例代码：

  apiVersion: apps/v1
  kind: Deployment
  metadata:
    name: web-nfs
  spec:
    selector:
      matchLabels:
        app: nginx-nfs
    replicas: 3
    template:
      metadata:
        labels:
          app: nginx-nfs
      spec:
        containers:
        - name: nginx-nfs
          image: nginx
          volumeMounts:
          - name: wwwroot
            mountPath: /usr/share/nginx/html
          ports:
          - containerPort: 80
        volumes:
        - name: wwwroot
          nfs:
            server: 10.100.24.85
            path: /ifs/kubernetes
  

2. 案例

2.1 安装和配置nfs

• 安装nfs

  [root@k8s-node1 ~]# yum install nfs-utils -y
  [root@k8s-node2 ~]# yum install nfs-utils -y
  [root@k8s-node3 ~]# yum install nfs-utils -y
  

• 用node3做本次的nfs共享磁盘

  • 修改nfs配置文件

    [root@k8s-node3 ~]# vi /etc/exports
    [root@k8s-node3 ~]# cat /etc/exports
    /ifs/kubernetes *(rw,no_root_squash)
    

  • 创建nfs共享目录

    [root@k8s-node3 ~]# mkdir -p /ifs/kubernetes
    

  • 创建index.html文件

    [root@k8s-node3 ~]# cd /ifs/kubernetes/
    [root@k8s-node3 kubernetes]# vim index.html
    [root@k8s-node3 kubernetes]# cat index.html
    <h1>hello world!</h1>
    

• 每个node都启动并设置开机启动

  [root@k8s-node3 ~]# systemctl start nfs      #启动nfs
  [root@k8s-node3 ~]# systemctl enable nfs     # 设置开机启动
  Created symlink from /etc/systemd/system/multi-user.target.wants/nfs-server.service to /usr/lib/systemd/system/nfs-server.service.
  
  

2.2 挂载nfs盘到pod容器

• 创建代码目录

  [root@k8s-master yaml]# mkdir -p nfs/
  [root@k8s-master yaml]# cd nfs/
  

• 编写pod代码

  [root@k8s-master nfs]# vim nfs.yaml
  [root@k8s-master nfs]# cat nfs.yaml
  apiVersion: apps/v1
  kind: Deployment
  metadata:
    name: web-nfs
  spec:
    selector:
      matchLabels:
        app: nginx-nfs
    replicas: 3
    template:
      metadata:
        labels:
          app: nginx-nfs
      spec:
        containers:
        - name: nginx-nfs
          image: nginx
          volumeMounts:
          - name: wwwroot
            mountPath: /usr/share/nginx/html
          ports:
          - containerPort: 80
        volumes:
        - name: wwwroot
          nfs:
            server: 10.100.24.85
            path: /ifs/kubernetes
  

• 启动服务

  [root@k8s-master nfs]# kubectl apply -f  nfs.yaml
  deployment.apps/web-nfs created
  

• 检查服务是否启动

  [root@k8s-master nfs]# kubectl get pods,service -o wide
  NAME                           READY   STATUS    RESTARTS   AGE     IP               NODE        NOMINATED NODE   READINESS GATES
  pod/configmap-demo-pod         1/1     Running   0          2d4h    10.244.107.209   k8s-node3   <none>           <none>
  pod/my-hostpath                1/1     Running   0          4h45m   10.244.107.211   k8s-node3   <none>           <none>
  pod/secret-demo-pod            1/1     Running   0          46h     10.244.107.210   k8s-node3   <none>           <none>
  pod/web-nfs-84f8d7bf8d-6mj75   1/1     Running   0          2m42s   10.244.107.212   k8s-node3   <none>           <none>
  pod/web-nfs-84f8d7bf8d-n4tpk   1/1     Running   0          2m42s   10.244.169.144   k8s-node2   <none>           <none>
  pod/web-nfs-84f8d7bf8d-qvd2z   1/1     Running   0          2m42s   10.244.36.84     k8s-node1   <none>           <none>
  
  NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE   SELECTOR
  service/kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   13d   <none>
  

• 检查内容是否存在

  [root@k8s-master nfs]# curl -I 10.244.107.212
  HTTP/1.1 200 OK
  Server: nginx/1.19.6
  Date: Mon, 28 Dec 2020 12:43:19 GMT
  Content-Type: text/html
  Content-Length: 22
  Last-Modified: Mon, 28 Dec 2020 12:17:10 GMT
  Connection: keep-alive
  ETag: "5fe9ccc6-16"
  Accept-Ranges: bytes
  
  [root@k8s-master nfs]# curl  10.244.107.212
  <h1>hello world!</h1>