四、pv,pvc+StatefulSet

一、基本概念
1、访问模式：
ReadWriteOnce：该卷可以被单个节点以读/写模式挂载
ReadOnlyMany：该卷可以被多个节点以只读模式挂载
ReadWriteMany：该卷可以被多个节点以读/写模式挂载
命令行中，访问模式缩写为：
RWO-ReadWriteOnce
ROX-ReadOnlyMany
RWX-ReadWriteMany

2、回收策略：
Retain(保留)：手动回收
Recycle(回收)：基本擦除（rm -rf ）。注：目前新版本只有HostPath支持
Delete(删除)：关联的存储资产将被删除

3、卷的状态：
Available(可用)：一块空闲资源还没有被任何声明绑定
Bound(已绑定)：卷已经被声明绑定
Released(已释放)：声明被删除，但是资源还未被集群重新声明
Failed(失败)：该卷的自动回收失败

二、实例，NFS的持久化演示
1、安装配置nfs服务端

[root@nginx02 /]# yum install -y nfs-common nfs-utils rpcbind
[root@nginx02 ~]# mkdir /data1
[root@nginx02 ~]# chmod 666 /data1
[root@nginx02 ~]# chown nfsnobody /data1
[root@nginx02 /]# cat etc/exports
/data1 *(rw,no_root_squash,no_all_squash,sync)
/data2 *(rw,no_root_squash,no_all_squash,sync)
/data3 *(rw,no_root_squash,no_all_squash,sync)
/data4 *(rw,no_root_squash,no_all_squash,sync)
[root@nginx02 /]# systemctl restart rpcbind
[root@nginx02 /]# systemctl restart nfs

2、node节点安装nfs工具，所有node节点都要安装

[root@k8s-node01 ~]# yum -y install nfs-utils
[root@k8s-node02 ~]#  yum -y install nfs-utils

3、部署PV

[root@k8s-master01-etcd01 pv-statefulset]# cat nfsdata1.yaml 
apiVersion: v1
kind: PersistentVolume
metadata:
  name: nfsdata1
spec:
  capacity:
    storage: 1Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: nfs
  nfs:
    path: /data1
    server: 10.16.8.156
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: nfsdata2
spec:
  capacity:
    storage: 1.5Gi
  accessModes:
    - ReadOnlyMany
  persistentVolumeReclaimPolicy: Retain
  storageClassName: nfs
  nfs:
    path: /data2
    server: 10.16.8.156

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: nfsdata3
spec:
  capacity:
    storage: 2Gi
  accessModes:
    - ReadWriteMany
  persistentVolumeReclaimPolicy: Retain
  storageClassName: nfs
  nfs:
    path: /data3
    server: 10.16.8.156
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: nfsdata4
spec:
  capacity:
    storage: 1Gi
  accessModes:
    - ReadWriteMany
  persistentVolumeReclaimPolicy: Retain
  storageClassName: nfs
  nfs:
    path: /data4
    server: 10.16.8.156

[root@k8s-master01-etcd01 pv-statefulset]# kubectl apply -f nfsdata1.yaml 

[root@k8s-master01-etcd01 pv-statefulset]# kubectl get pv
NAME       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM   STORAGECLASS   REASON   AGE
nfsdata1   1Gi        RWO            Retain           Available           data1                   8m47s
nfsdata2   1536Mi     ROX            Retain           Available           data2                   49s
nfsdata3   2Gi        RWX            Retain           Available           data3                   49s
nfsdata4   1Gi        RWX            Retain           Available           data4                   49s

4、deployment使用pvc

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mypvc
  namespace: default
spec:
  accessModes: ["ReadWriteMany"]
  storageClassName: "nfs"
  resources:
    requests:
      storage: 1Gi               

---
apiVersion: v1
kind: Service
metadata:
  name: xiangwei-service
  labels:
    app: nginx
spec:
  type: NodePort
  ports:
  - port: 80    
    targetPort: 80
    nodePort: 30801
  selector:
    app: xiangwei-web

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  namespace: default
spec:
  replicas: 3
  selector:
    matchLabels:
      app: xiangwei-web
  template:
    metadata:
      labels:
        app: xiangwei-web
    spec:
      nodeSelector:
        app: dev
      containers:
      - name: nginx
        image: nginx:1.15
        volumeMounts:
        - name: wwwroot
          mountPath: /usr/share/nginx/html
        ports:
        - containerPort: 80
      volumes:
      - name: wwwroot
        persistentVolumeClaim:
          claimName: mypvc

5、StatefulSet控制器使用pvc

apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  ports:
  - port: 80
    name: web
  clusterIP: None
  selector:
    app: nginx
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
spec:
  selector:
    matchLabels:
      app: nginx
  serviceName: "nginx"
  replicas: 3
  template:
    metadata:
      labels:
        app: nginx
    spec:
      nodeSelector:
        app: dev
      containers:
      - name: nginx
        image: nginx:1.15
        ports:
        - containerPort: 80
          name: web
        volumeMounts:
        - name: www
          mountPath: /usr/share/nginx/html
  volumeClaimTemplates:
  - metadata:
      name: www
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: "nfs" 
      resources:
        requests:
          storage: 1Gi