4. 存储 10%¶

1. 了解存储类、持久卷¶

Understand storage classes, persistent volumes

PV
集群中的一块存储 emptyDir # 容器中 hostPath # 宿主机中 local
PVC
用户对存储的请求
StorageClass
存储 "类"的描述方法，通过描述存储类，提供动态分配存储的能力

2. 了解卷模式、访问模式和卷回收策略¶

Understand volume mode, access modes and reclaim policies for volumes

volume mode
- Filesystem（文件系统）
- Block（块）
access modes
- ReadWriteOnce -- 卷可以被一个节点以读写方式挂载；
- ReadOnlyMany -- 卷可以被多个节点以只读方式挂载；
- ReadWriteMany -- 卷可以被多个节点以读写方式挂载。
reclaim policies
- Retain -- 手动回收
- Recycle -- 基本擦除 (rm -rf /thevolume/*)
- Delete -- 诸如 AWS EBS、GCE PD、Azure Disk 或 OpenStack Cinder 卷这类关联存储资产也被删除

3. 理解持久容量声明原语¶

Understand persistent volume claims primitive

apiVersion: v1
kind: PersistentVolume
metadata:
    name: pv0003
spec:
    volumeMode: Filesystem
    accessModes:
    - ReadWriteOnce
    capacity:
    storage: 5Gi
    persistentVolumeReclaimPolicy: Recycle
    storageClassName: slow
    mountOptions:
    - hard
    - nfsvers=4.1
    nfs:
    path: /tmp
    server: 172.17.0.2

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
    name: myclaim
spec:
    volumeMode: Filesystem
    accessModes:
    - ReadWriteOnce
    storageClassName: slow
    resources:
    requests:
        storage: 8Gi
    selector:
    matchLabels:
        release: "stable"
    matchExpressions:
        - {key: environment, operator: In, values: [dev]}

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
    name: standard
provisioner: kubernetes.io/aws-ebs
parameters:
    type: gp2
reclaimPolicy: Retain
allowVolumeExpansion: true
mountOptions:
    - debug
volumeBindingMode: Immediate

4. 了解如何配置具有持久性存储的应用程序¶

Know how to configure applications with persistent storage

参考¶

PV

StorageClass

题目¶

列出环境内所有的 pv 并以 name 字段排序（使用 kubectl 自带排序功能）
```
kubectl get pv -A --sort-by='.metadata.name'
```

创建一个 pv，类型是 hostPath ，位于 /data 中，大小 1G，模式 ReadOnlyMany

apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv1
  namespace: xx
spec:
  accessModes:
    - ReadOnlyMany
  hostPath:
    path: /data
  capacity:
    storage: 1Gi

创建一个 pod 名称为 test，镜像为 nginx ，Volume 名称 cache-volume 为挂在在 /data 目录下，且 Volume 是 non-Persistent 的

apiVersion: v1
kind: Deployment
metdata:
  name: test
spec:
  template:
    metadata:
      name: test
    spec:
      conatiners:
        - name: nginx
          image: nginx
          volumeMounts:
            name: cache-volume
            mountPath: /data

List all PVs sorted by name,saving the full kubectl output to /opt/KUCC0010/my_volumes. Use kubectl own functionally for sorting the output, and do not manipulate it any further.
pod中挂载volume