一、kubernetes存储卷类型分类

kubernetes存储卷可支持的类型有如下所示：

[root@master1 ~]# kubectl explain pods.spec.volumes
KIND:     Pod
VERSION:  v1

RESOURCE: volumes <[]Object>

DESCRIPTION:
     List of volumes that can be mounted by containers belonging to the pod.
     More info: https://kubernetes.io/docs/concepts/storage/volumes

     Volume represents a named volume in a pod that may be accessed by any
     container in the pod.

FIELDS:
   awsElasticBlockStore	<Object>
     AWSElasticBlockStore represents an AWS Disk resource that is attached to a
     kubelet's host machine and then exposed to the pod. More info:
     https://kubernetes.io/docs/concepts/storage/volumes#awselasticblockstore

   azureDisk	<Object>
     AzureDisk represents an Azure Data Disk mount on the host and bind mount to
     the pod.

   azureFile	<Object>
     AzureFile represents an Azure File Service mount on the host and bind mount
     to the pod.

   cephfs	<Object>
     CephFS represents a Ceph FS mount on the host that shares a pod's lifetime

   cinder	<Object>
     Cinder represents a cinder volume attached and mounted on kubelets host
     machine. More info: https://examples.k8s.io/mysql-cinder-pd/README.md

   configMap	<Object>
     ConfigMap represents a configMap that should populate this volume

   csi	<Object>
     CSI (Container Storage Interface) represents storage that is handled by an
     external CSI driver (Alpha feature).

   downwardAPI	<Object>
     DownwardAPI represents downward API about the pod that should populate this
     volume

   emptyDir	<Object>
     EmptyDir represents a temporary directory that shares a pod's lifetime.
     More info: https://kubernetes.io/docs/concepts/storage/volumes#emptydir

   fc	<Object>
     FC represents a Fibre Channel resource that is attached to a kubelet's host
     machine and then exposed to the pod.

   flexVolume	<Object>
     FlexVolume represents a generic volume resource that is
     provisioned/attached using an exec based plugin.

   flocker	<Object>
     Flocker represents a Flocker volume attached to a kubelet's host machine.
     This depends on the Flocker control service being running

   gcePersistentDisk	<Object>
     GCEPersistentDisk represents a GCE Disk resource that is attached to a
     kubelet's host machine and then exposed to the pod. More info:
     https://kubernetes.io/docs/concepts/storage/volumes#gcepersistentdisk

   gitRepo	<Object>
     GitRepo represents a git repository at a particular revision. DEPRECATED:
     GitRepo is deprecated. To provision a container with a git repo, mount an
     EmptyDir into an InitContainer that clones the repo using git, then mount
     the EmptyDir into the Pod's container.

   glusterfs	<Object>
     Glusterfs represents a Glusterfs mount on the host that shares a pod's
     lifetime. More info: https://examples.k8s.io/volumes/glusterfs/README.md

   hostPath	<Object>
     HostPath represents a pre-existing file or directory on the host machine
     that is directly exposed to the container. This is generally used for
     system agents or other privileged things that are allowed to see the host
     machine. Most containers will NOT need this. More info:
     https://kubernetes.io/docs/concepts/storage/volumes#hostpath

   iscsi	<Object>
     ISCSI represents an ISCSI Disk resource that is attached to a kubelet's
     host machine and then exposed to the pod. More info:
     https://examples.k8s.io/volumes/iscsi/README.md

   name	<string> -required-
     Volume's name. Must be a DNS_LABEL and unique within the pod. More info:
     https://kubernetes.io/docs/concepts/overview/working-with-objects/names/#names

   nfs	<Object>
     NFS represents an NFS mount on the host that shares a pod's lifetime More
     info: https://kubernetes.io/docs/concepts/storage/volumes#nfs

   persistentVolumeClaim	<Object>
     PersistentVolumeClaimVolumeSource represents a reference to a
     PersistentVolumeClaim in the same namespace. More info:
     https://kubernetes.io/docs/concepts/storage/persistent-volumes#persistentvolumeclaims

   photonPersistentDisk	<Object>
     PhotonPersistentDisk represents a PhotonController persistent disk attached
     and mounted on kubelets host machine

   portworxVolume	<Object>
     PortworxVolume represents a portworx volume attached and mounted on
     kubelets host machine

   projected	<Object>
     Items for all in one resources secrets, configmaps, and downward API

   quobyte	<Object>
     Quobyte represents a Quobyte mount on the host that shares a pod's lifetime

   rbd	<Object>
     RBD represents a Rados Block Device mount on the host that shares a pod's
     lifetime. More info: https://examples.k8s.io/volumes/rbd/README.md

   scaleIO	<Object>
     ScaleIO represents a ScaleIO persistent volume attached and mounted on
     Kubernetes nodes.

   secret	<Object>
     Secret represents a secret that should populate this volume. More info:
     https://kubernetes.io/docs/concepts/storage/volumes#secret

   storageos	<Object>
     StorageOS represents a StorageOS volume attached and mounted on Kubernetes
     nodes.

   vsphereVolume	<Object>
     VsphereVolume represents a vSphere volume attached and mounted on kubelets
     host machine

二、存储卷使用演示实例

1.emptyDir

自主式pod演示emptyDir存储卷类型的使用方法如下：

apiVersion: v1
kind: Pod
metadata:
  name: pod-vol
  namespace: default
  labels:
    app: myapp
    tier: frontend
  annotations:
    qjbj.com/created-by: "cluster admin"
spec:
  containers:
  - name: myapp
    image: ikubernetes/myapp:v1
    ports:
    - name: http
      containerPort: 80
    volumeMounts:
    - name: html
      mountPath: /usr/share/nginx/html/
  - name: busybox
    image: busybox:latest
    imagePullPolicy: IfNotPresent
    volumeMounts:
    - name: html
      mountPath: /data/
    command:
    - "/bin/sh"
    - "-c"
    - "while true; do echo $(date) >> /data/index.html; sleep 5; done"
  volumes:
  - name: html
    emptyDir: {}

2.hostPath

hostPath的存储卷会直接使用node节点的存储资源来存储数据，其中type为DirectoryOrCreate表示若没有此路径，则自动创建。

apiVersion: v1
kind: Pod
metadata:
  name: podvolhostpath
  namespace: default
spec:
  containers:
  - name: myappvol
    image: ikubernetes/myapp:v1
    volumeMounts:
    - name: html
      mountPath: /usr/share/nginx/html/
  volumes:
  - name: html
    hostPath:
      path: /data/pod/volume1
      type: DirectoryOrCreate

在目录/data/pod/volume1下创建测试文件index.html，添加内容如”i am host content.”，测试结果如下：

[root@node1 /]# curl 10.244.2.45
i am host content.

3.nfs

nfs服务器安装部署nfs参考：linux服务器安装部署和使用nfs总结

apiVersion: v1
kind: Pod
metadata:
  name: podvolnfs
  namespace: default
spec:
  containers:
  - name: myappvol
    image: ikubernetes/myapp:v1
    volumeMounts:
    - name: html
      mountPath: /usr/share/nginx/html/
  volumes:
  - name: html
    nfs:
      path: /data/volumes
      server: 192.168.222.153

在nfs服务器共享目录/data/volumes下创建index.html文件，添加内容如”i am nfs server.”，用生成的pod资源的IP地址直接访问，如下：

[root@node1 ~]# curl 10.244.2.47
i am nfs server.

4.pv和pvc【重点】

模拟准备：在nfs服务器上模拟出3个共享目录，如下：

root@storage01:/data/volumes# exportfs -arv
exporting *:/data/volumes/v3
exporting *:/data/volumes/v2
exporting *:/data/volumes/v1
root@storage01:/data/volumes# showmount -e
clnt_create: RPC: Unknown host
root@storage01:/data/volumes# showmount -e 192.168.222.153
Export list for 192.168.222.153:
/data/volumes/v3 *
/data/volumes/v2 *
/data/volumes/v1 *

创建pv