k8s-持久卷pv和pvc使用

1. k8s-持久卷概述

• PersistentVolume（PV）：对存储资源创建和使用的抽象，使得存储作为集群中的资源管理
• PersistentVolumeClaim（PVC）：让用户不需要关心具体的Volume实现细节

2. pv与pvc使用流程

• 官网参考地址： 支持持久卷的存储插件：https://kubernetes.io/docs/concepts/storage/persistent-volumes/

2.1 示例代码

• 数据卷定义pv

  apiVersion: v1
  kind: PersistentVolume         # 创建pv
  metadata:
    name: my-pv               # 创建名称
  spec:
    capacity:
      storage: 5Gi            # pv容量5G磁盘内容
    accessModes:
      - ReadWriteMany
    nfs:
      path: /ifs/kubernetes
      server: 10.100.24.85
  
  

• 卷需求模板pvc

  apiVersion: v1
  kind: PersistentVolumeClaim
  metadata:
    name: my-pvc
  spec:
    accessModes:
      - ReadWriteMany
    resources:
      requests:
        storage: 5Gi
  

• 容器pod应用pvc卷

  apiVersion: v1
  kind: Pod
  metadata:
    name: my-pod
  spec:
    containers:
    - name: nginx
      image: nginx:latest
      ports:
      - containerPort: 80
      volumeMounts:
      - name: www
        mountPath: /usr/share/nginx/html
    volumes:
      - name: www
        persistentVolumeClaim:
          claimName: my-pvc
  

3. 案例

3.1 配置pv卷

• 创建pv的yaml文件目录

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

• 编写pv卷磁盘大小

  [root@k8s-master pv]# vim pv.yaml
  [root@k8s-master pv]# cat pv.yaml
  apiVersion: v1
  kind: PersistentVolume         # 创建pv
  metadata:
    name: my-pv               # 创建名称
  spec:
    capacity:
      storage: 5Gi            # pv容量5G磁盘内容
    accessModes:
      - ReadWriteMany
    nfs:
      path: /ifs/kubernetes
      server: 10.100.24.85
  

• 启动配置文件

  [root@k8s-master pv]# kubectl apply -f pv.yaml 
  persistentvolume/my-pv created
  

• 验证服务是否启动

  [root@k8s-master pv]# kubectl get pv
  NAME    CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM   STORAGECLASS   REASON   AGE
  my-pv   5Gi        RWX            Retain           Available                                   5s
  

3.2 配置pvc卷

• 创建pvc的yaml文件目录

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

• 编写pvc配置文件

  [root@k8s-master pvc]# vim pvc.yaml
  [root@k8s-master pvc]# cat pvc.yaml
  apiVersion: v1
  kind: PersistentVolumeClaim
  metadata:
    name: my-pvc
  spec:
    accessModes:
      - ReadWriteMany
    resources:
      requests:
        storage: 5Gi
  

• 启动pvc配置文件

  [root@k8s-master pvc]# kubectl apply -f pvc.yaml 
  persistentvolumeclaim/my-pvc created
  

• 验证pvc是否启动

  [root@k8s-master pvc-pod]# kubectl get pvc
  NAME     STATUS   VOLUME   CAPACITY   ACCESS MODES   STORAGECLASS   AGE
  my-pvc   Bound    my-pv    5Gi        RWX                           3s
  

3.3 配置容器使用pvc卷

• 创建pvc容器卷的目录

  [root@k8s-master yaml]# mkdir pvc-pod
  [root@k8s-master yaml]# cd pvc-pod/
  

• 创建pvc配置文件

  [root@k8s-master pvc-pod]# vim pod.yaml 
  [root@k8s-master pvc-pod]# cat pod.yaml 
  apiVersion: v1
  kind: Pod
  metadata:
    name: my-pod
  spec:
    containers:
    - name: nginx
      image: nginx:latest
      ports:
      - containerPort: 80
      volumeMounts:
      - name: www
        mountPath: /usr/share/nginx/html
    volumes:
      - name: www
        persistentVolumeClaim:
          claimName: my-pvc
  

• 启动配置文件

  [root@k8s-master pvc-pod]# kubectl apply -f pod.yaml 
  pod/my-pod created
  

• 验证服务是否启动

  [root@k8s-master pvc-pod]# kubectl get pods -o wide
  NAME                       READY   STATUS    RESTARTS   AGE     IP               NODE        NOMINATED NODE   READINESS GATES
  configmap-demo-pod         1/1     Running   0          3d17h   10.244.107.209   k8s-node3   <none>           <none>
  my-hostpath                1/1     Running   4          41h     10.244.107.211   k8s-node3   <none>           <none>
  my-pod                     1/1     Running   0          5m12s   10.244.36.86     k8s-node1   <none>           <none>
  secret-demo-pod            1/1     Running   0          3d11h   10.244.107.210   k8s-node3   <none>           <none>
  web-nfs-84f8d7bf8d-6mj75   1/1     Running   0          37h     10.244.107.212   k8s-node3   <none>           <none>
  web-nfs-84f8d7bf8d-n4tpk   1/1     Running   0          37h     10.244.169.144   k8s-node2   <none>           <none>
  web-nfs-84f8d7bf8d-qvd2z   1/1     Running   0          37h     10.244.36.84     k8s-node1   <none>           <none>
  

• curl请求一下

  [root@k8s-master pvc-pod]# curl 10.244.36.86
  <h1>hello world!</h1>