9. kubernetes资源——pv/pvc持久卷

一、volume数据卷

用于pod中的数据的持久化存储
支持很多的卷类型, 例如EmptyDir、hostPath、NAS、SAN、CEPH

1、hostPath

挂载物理机上的目录做持久化

apiVersion: apps/v1
kind: Deployment
metadata:name: test1-hostpath
spec:replicas: 1selector:matchLabels:app: hostpathtemplate:metadata:labels:app: hostpathspec:containers:- name: test1-hostpathimage: centos:7imagePullPolicy: IfNotPresentcommand:- sleep- "3600"volumeMounts:													// 挂载卷- name: test1-volumemountPath: /test1volumes:																	// 创建卷，名称为test1-volume， 类型为hostpath- name: test1-volumehostPath:path: /test/data

[root@k8s-master ~]# kubectl get pod -o wide
NAME                              READY   STATUS    RESTARTS   AGE    IP              NODE                   NOMINATED NODE   READINESS GATES
test1-hostpath-584f599fcf-wzt2q   1/1     Running   0          117s   10.88.201.193   k8s-node01.linux.com   <none>           <none>
[root@k8s-master ~]# 
[root@k8s-master ~]# kubectl exec -ti test1-hostpath-584f599fcf-wzt2q bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
[root@test1-hostpath-584f599fcf-wzt2q /]# 
[root@test1-hostpath-584f599fcf-wzt2q /]# touch /test1/{1..10}
[root@test1-hostpath-584f599fcf-wzt2q /]# ls /test1/
1  10  2  3  4  5  6  7  8  9
[root@test1-hostpath-584f599fcf-wzt2q /]# 
[root@test1-hostpath-584f599fcf-wzt2q /]# exit
exit

2、挂载nfs实现持久化

apiVersion: apps/v1
kind: Deployment
metadata:name: test2-pod-nfs
spec:replicas: 1selector:matchLabels:app: nfstemplate:metadata:labels:app: nfsspec:containers:- name: test2-pod-nfsimage: centos:7imagePullPolicy: IfNotPresentcommand:- sleep- "3600"volumeMounts:- name: test2-nfs-volumemountPath: /test2volumes:- name: test2-nfs-volumenfs:server: "192.168.140.13"path: "/test2"

二、pv/pvc 持久卷/持久卷声明

1、pv/pvc介绍

pv， 持久卷，后端真实存储空间的映射
pvc， 持久卷声明，使用存储的申请

使用流程:
1、创建pv，描述后端真实的存储空间
2、创建pvc，描述使用存储的申请
3、创建pod，挂载pvc使用存储

2、pv/pvc的使用流程

2.1 创建pv

apiVersion: v1
kind: PersistentVolume
metadata:name: pv-2g
spec:capacity:storage: 2GaccessModes:- ReadWriteManypersistentVolumeReclaimPolicy: Recyclenfs:server: "192.168.140.13"path: "/test6"

apiVersion: v1
kind: PersistentVolume
metadata:name: pv-3g
spec:capacity:storage: 3GaccessModes:- ReadWriteOncepersistentVolumeReclaimPolicy: Recyclenfs:server: "192.168.140.13"path: "/test7"

accessModes：用于指定PV的访问模式，共有四种

• ReadWriteOnce
  被单个节点以读写模式挂载

• ReadWriteMany
  被多个节点以读写模式挂载

• ReadOnlyMany
  被多个节点以只读模式挂载

• ReadOnlyOnce, k8s 1.29
  被单节点以只读模式挂载

persistentVolumeReclaimPolicy:
指定回收模式是自动回收，当空间被释放时，K8S自动清理，然后可以继续绑定使用

[root@k8s-master pvTest]# kubectl get pv
NAME    CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM   STORAGECLASS   VOLUMEATTRIBUTESCLASS   REASON   AGE
pv-2g   2G         RWX            Recycle          Available                          <unset>                          2m26s
pv-3g   3G         RWO            Recycle          Available                          <unset>                          46s

2.2 创建pvc

apiVersion: v1
kind: PersistentVolumeClaim
metadata:name: pvc-1g
spec:accessModes:- ReadWriteManyresources:requests:storage: 1G

[root@k8s-master pvTest]# kubectl get pvc
NAME     STATUS   VOLUME   CAPACITY   ACCESS MODES   STORAGECLASS   VOLUMEATTRIBUTESCLASS   AGE
pvc-1g   Bound    pv-2g    2G         RWX                           <unset>                 10s```bash
[root@k8s-master pvTest]# kubectl get pv
NAME    CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM            STORAGECLASS   VOLUMEATTRIBUTESCLASS   REASON   AGE
pv-2g   2G         RWX            Recycle          Bound       default/pvc-1g                  <unset>                          10m
pv-3g   3G         RWO            Recycle          Available                                   <unset>                          8m34s

2.3 创建pod，使用pv做持久化

apiVersion: apps/v1
kind: Deployment
metadata:name: test1-pod
spec:replicas: 1selector:matchLabels:app: pvtemplate:metadata:labels:app: pvspec:containers:- name: test1-podimage: centos:7imagePullPolicy: IfNotPresentcommand:- sleep- "3600"volumeMounts:- name: test1-pod-pv-volumemountPath: /test1volumes:- name: test1-pod-pv-volumepersistentVolumeClaim:														// 通过关联pvc创建数据卷claimName: pvc-1g