kubernetes-volume存储管理

本地存储

emptyDir

    物理机随机生成目录,挂在到容器中,容器删除则挂在目录删除,不保留数据.

    主要用于容器之间通信,共享数据.

[root@bjcy-200 volume]# cat volume1.yaml 
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: nginx-v1
  name: nginx-v1
spec:
  volumes:
  - name: volume1
    emptyDir: {}
  containers:
  - image: harbor.tcc.com/public/nginx
    name: nginx-v1
    volumeMounts:
    - name: volume1
      mountPath: /dir
    resources: {}
  dnsPolicy: ClusterFirst
  restartPolicy: Always
status: {}

hostPath

   hostpath方式可以实现持久存储.但是不方便管理,和主机耦合性比较强,比较依赖主机.

[root@bjcy-200 volume]# cat hostpath.yaml 
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: nginx-v1
  name: nginx-v1
spec:
  volumes:
  - name: volume1
    hostPath:
      path: /data/volume/nginx
  containers:
  - image: harbor.tcc.com/public/nginx
    name: nginx-v1
    volumeMounts:
    - name: volume1
      mountPath: /dir
    resources: {}
  dnsPolicy: ClusterFirst
  restartPolicy: Always
status: {}

网络存储

   kubernetes支持的网络存储: https://kubernetes.io/docs/concepts/storage/volumes/

NFS

    nfs-server:  /tmp *(rw,async,no_root_squash) 

[root@bjcy-200 volume]# cat nfs.yaml 
apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    run: nginx-v1
  name: nginx-v1
spec:
  volumes:
  - name: volume1
    nfs:
      path: /tmp
      server: 172.17.0.2
  containers:
  - image: harbor.tcc.com/public/nginx
    name: nginx-v1
    volumeMounts:
    - name: volume1
      mountPath: /dir
    resources: {}
  dnsPolicy: ClusterFirst
  restartPolicy: Always
status: {}

iscsi

---
apiVersion: v1
kind: Pod
metadata:
  name: iscsipd
spec:
  containers:
  - name: iscsipd-rw
    image: kubernetes/pause
    volumeMounts:
    - mountPath: "/mnt/iscsipd"
      name: iscsipd-rw
  volumes:
  - name: iscsipd-rw
    iscsi:
      targetPortal: 10.0.2.15:3260
      iqn: iqn.2001-04.com.example:storage.kube.sys1.xyz
      lun: 0
      fsType: xfs
      readOnly: true

持久性存储

    官网地址: https://kubernetes.io/docs/concepts/storage/persistent-volumes/

    persistentvolumes 通过pv关联后端存储,pv对全局可见.用户通过创建vpc使用持久性存储, pvc不是全局可见.

    PVC和PV是一一对应的。

主要参数

accessmode

     pvc和pv关联主要通过: accessmode

参数	说明
ReadWriteOnce	可读可写单node节点挂载
ReadOnlyMany	可读权限单node节点挂载
ReadWriteMany	可读可写多node节点挂载

pv回收策略

    persistentVolumeReclaimPolicy

参数	说明
Recycle	pvc被删除则删除数据,系统会生成一个pod把对应的数据删除掉. pv状态变成Available,此时pv可以被复用.
Retain	不会被删除数据,但是删除pvc后,pv仍然不可用. pv状态长期保持为Released

storageClassName

    类似name值,pvc要和pv关联 storageClassName 值必须相同.

storage 

  pvc指定的 storage 大小不能大于 pv storage 大小.

示例

pv

[root@bjcy-200 volume]# cat nfs-pv.yaml 
apiVersion: v1
kind: PersistentVolume
metadata:
  name: nfs-pv
spec:
  capacity:
    storage: 5Gi
  volumeMode: Filesystem
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Recycle
  storageClassName: slow
  mountOptions:
    - hard
    - nfsvers=4
  nfs:
    path: /vdisk
    server: 172.16.0.141

检查
[root@bjcy-200 volume]# kubectl get pv
NAME     CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM   STORAGECLASS   REASON   AGE
nfs-pv   5Gi        RWO            Recycle          Available           slow                    97

pvc

[root@bjcy-200 volume]# cat pvc.yaml 
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: nfs-pvc2
spec:
  accessModes:
    - ReadWriteOnce
  volumeMode: Filesystem
  resources:
    requests:
      storage: 5Gi
  storageClassName: slow
[root@bjcy-200 volume]# kubectl apply -f pvc.yaml 
persistentvolumeclaim/nfs-pvc2 created
[root@bjcy-200 volume]# kubectl get pv
NAME     CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM              STORAGECLASS   REASON   AGE
nfs-pv   5Gi        RWO            Recycle          Bound    default/nfs-pvc2   slow                    55s
[root@bjcy-200 volume]# kubectl get pvc
NAME       STATUS   VOLUME   CAPACITY   ACCESS MODES   STORAGECLASS   AGE
nfs-pvc2   Bound    nfs-pv   5Gi        RWO            slow           9s