kubernetes 存储volume，pv和pvc的使用

emptyDIR 临时目录

hostPath :使用主机的路径

网络存储：

　　传统的设备存储：NAS,SAN

　　分布式存储：glusterfs，rbd，cephfs

    　云存储：EBS,Azure，阿里云的 

一、emptyDir 的类型：一个pod里面2个容易，挂载同一个目录，

注意：emptyDir的生命周期同pod周期，简单来说，pod删除了，emptyDir也随之删除

apiVersion: v1
kind: Pod
metadata:
  name: pod-demo
  namespace: default
  labels:
    app: myapp
    tier: frontend
spec:
  containers:
  - name: myapp
    image: ikubernetes/myapp:v1
    ports:
    - name: http
      containerPort: 80
    volumeMounts:  #容器挂载
    - name: html
      mountPath: /data/web/html/
  - name: busybox
    image: busybox:latest
    command: ["/bin/sh" ,"-c","sleep 3600"]
    volumeMounts:   #容器挂载
    - name: html
      mountPath: /data/
  volumes:     #定义存储
  - name: html
    emptyDir: {}

二、hostPath 类型存储

apiVersion: v1
kind: Pod
metadata:
  name: nginx-volume
  namespace: default
spec:
  containers:
  - name: nginx
    image: nginx
    ports:
    - containerPort: 80
    volumeMounts:
    - name: html
      mountPath: /usr/share/nginx/html/
  volumes:
  - name: html
    hostPath:
      path: /data/nginx/v1/
      type: DirectoryOrCreate

三、nfs 类型存储

首先要准备好nfs，我在172.17.1.36的机器上安装nfs，到处的目录为/nfs/data

yum install nfs-utils

vim vim /etc/exports   

/nfs/data/    172.17.0.0/16(rw,no_root_squash)   

systemctl start nfs

nfs准备好了，注意，在pod的节点机器要一定确定可以挂载nfs类型的，否则创建pod会出错。执行yum install nfs-utils  就可以挂载了

nfs pod 的yaml文件：

apiVersion: v1
kind: Pod
metadata:
  name: nginx-volume-nfs
  namespace: default
spec:
  containers:
  - name: nginx-nfs
    image: nginx
    ports:
    - containerPort: 80
    volumeMounts:
    - name: html
      mountPath: /usr/share/nginx/html/
  volumes:
  - name: html
    nfs:
      path: /nfs/data/
      server: 172.17.1.36

四、pv，pvc的使用

对于pv和pvc，首先要准备存储的，我用的是nfs，在172.17.1.36的节点上划分了5个路径作为存储的设备。

mkdir /data/{v1,v2,v3,v4,v5} -pv

vim /etc/exports

添加如下的内容：

/data/v1 172.17.0.0/16(rw,no_root_squash)
/data/v2 172.17.0.0/16(rw,no_root_squash)
/data/v3 172.17.0.0/16(rw,no_root_squash)
/data/v4 172.17.0.0/16(rw,no_root_squash)
/data/v5 172.17.0.0/16(rw,no_root_squash)

保存，导出下。

exportfs -avr

查看下是否正常。

nfs的存储的好了。下一步要先创建pv，yaml文件如下

apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv01
  labels:
    name: pv01
spec:
  nfs:
    path: /data/v1/
    server: 172.17.1.36
  accessModes: ["ReadWriteOnce","ReadWriteMany"]
  capacity:
    storage: 5Gi
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv02
  labels:
    name: pv02
spec:
  nfs:
    path: /data/v2/
    server: 172.17.1.36
  accessModes: ["ReadWriteOnce","ReadWriteMany"]
  capacity:
    storage: 3Gi
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv03
  labels:
    name: pv03
spec:
  nfs:
    path: /data/v3/
    server: 172.17.1.36
  accessModes: ["ReadWriteOnce","ReadWriteMany"]
  capacity:
    storage: 5Gi
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv04
  labels:
    name: pv04
spec:
  nfs:
    path: /data/v4/
    server: 172.17.1.36
  accessModes: ["ReadWriteOnce","ReadWriteMany"]
  capacity:
    storage: 10Gi
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv05
  labels:
    name: pv05
spec:
  nfs:
    path: /data/v5/
    server: 172.17.1.36
  accessModes: ["ReadWriteOnce","ReadWriteMany"]
  capacity:
    storage: 10Gi

 kubectl apply -f pv-nfs.yaml

显示，pv创建完成

接下来创建pvc 和pod，yaml文件如下

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mypvc
  namespace: default
spec:
  accessModes: ["ReadWriteMany"]
  resources:
    requests:
      storage: 5Gi               #到这里是创建pvc的
---
apiVersion: v1
kind: Pod
metadata:
  name: nginx-volume-pvc
  namespace: default
spec:
  containers:
  - name: nginx-pvc
    image: nginx
    ports:
    - containerPort: 80
    volumeMounts:
    - name: html
      mountPath: /usr/share/nginx/html/
  volumes:               #这里是选择volume的类型
  - name: html
    persistentVolumeClaim:
      claimName: mypvc

 显示pvc创建好了，同时pvc绑定了一个pv，到此pv和pvc的安装部署完成。

ps：pv和pvc是一对一绑定的。但是多个pod可以挂载同一个pvc  

通常使用的流程是，首先创建存储，在创建pv，接着创建pvc，pod挂载到相应的pvc。