完成下列实验需搭建k8s集群环境如下：

* master节点IP：192.168.45.129

* node01节点IP：192.168.45.141

* node02节点IP：192.168.45.142

注：这里实验环境提前搭建好了如想搭建k8s集群前参考博文：kubeadm部署kubernetes(k8s)集群

1)搭建NFS共享存储

本次案例直接在master节点上创建NFS存储！

[[email protected] ~]# yum -y install nfs-utils rpcbind

[[email protected] ~]# vim /etc/exports

/nfsdata *(rw,sync,no_root_squash)

[[email protected] ~]# systemctl start nfs-server

[[email protected] ~]# systemctl start rpcbind

[[email protected] ~]# showmount -e

Export list for master:

/nfsdata *

2)创建PV资源对象

[[email protected] ~]# vim mysql-pv.yaml //编写pv的yaml文件

apiVersion: v1

kind: PersistentVolume

metadata:

name: mysql-pv

spec:

capacity:

storage: 1Gi

accessModes:

- ReadWriteOnce //访问模式定义为只能以读写的方式挂载到单个节点

persistentVolumeReclaimPolicy: Retain //注意指定的回收策略为手动回收

storageClassName: nfs

nfs:

path: /nfsdata/mysql-pv

server: 192.168.45.129

[[email protected] ~]# kubectl apply -f mysql-pv.yaml //执行yaml文件

[[email protected] ~]# kubectl get pv

NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE

mysql-pv 1Gi RWO Retain Available nfs 7s

[[email protected] ~]# mkdir -p /nfsdata/mysql-pv

3)创建PVC资源对象

[[email protected] ~]# vim mysql-pvc.yaml //编写pvcyaml文件

apiVersion: v1

kind: PersistentVolumeClaim

metadata:

name: mysql-pvc

spec:

accessModes:

- ReadWriteOnce

resources:

requests:

storage: 1Gi

storageClassName: nfs //这里指定关联的PV名称

[[email protected] ~]# kubectl apply -f mysql-pvc.yaml //执行yaml文件

[[email protected] ~]# kubectl get pv,pvc

//查看pv和pvc已经关联上了

//PV和PVC的状态类应该全是Bound。

NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE

persistentvolume/mysql-pv 1Gi RWO Retain Bound default/mysql-pvc nfs 108s

NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE

persistentvolumeclaim/mysql-pvc Bound mysql-pv 1Gi RWO nfs 21s

4)创建pod资源

[[email protected] ~]# vim mysql-pod.yaml //编写pod的yaml文件

apiVersion: extensions/v1beta1

kind: Deployment

metadata:

name: mysql-pod

spec:

selector: //设置给予等值的标签选择器

matchLabels:

app: mysql

template:

metadata:

labels:

app: mysql

spec:

containers:

- image: mysql:5.6

name: mysql

env: //设置环境变量，数据库root用户的密码

- name: MYSQL_ROOT_PASSWORD

value: 123.com

volumeMounts:

- name: mysql-storage

mountPath: /var/lib/mysql //这个目录是数据库存放数据的目录(指定的是容器中的目录)

volumes:

- name: mysql-storage

persistentVolumeClaim:

claimName: mysql-pvc //指定pvc的名称

[[email protected] ~]# kubectl apply -f mysql-pod.yaml

[[email protected] ~]# kubectl get pod

NAME READY STATUS RESTARTS AGE

mysql-pod-6cc889468b-g8cw6 1/1 Running 0 39s

5)测试数据持久化效果

[[email protected] ~]# kubectl get pod -o wide //查看容器的ID

NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES

mysql-pod-6cc889468b-g8cw6 1/1 Running 0 3m54s 10.244.2.2 node01

[[email protected] ~]# kubectl exec -it mysql-pod-6cc889468b-g8cw6 -- mysql -u root -p123.com

//直接登录运行mysql数据库的pod中的mysql

//插入数据进行测试

mysql> create database bjq;

Query OK, 1 row affected (0.00 sec)

mysql> use bjq;

Database changed

mysql> create table my_id( id int(4) );

Query OK, 0 rows affected (0.03 sec)

mysql> insert my_id values (9527);

Query OK, 1 row affected (0.01 sec)

mysql> select * from my_id;

+------+

| id |

+------+

| 9527 |

+------+

1 row in set (0.00 sec)

[[email protected] ~]# ls /nfsdata/mysql-pv/ //查看pod对应的NFS的目录，确实有了数据

auto.cnf bjq ibdata1 ib_logfile0 ib_logfile1 mysql performance_schema

6)模拟MySQL容器所在的节点宕机，验证数据是否会丢失

[[email protected] ~]# kubectl get pod -o wide

//查看到pod是运行在node01节点上的

//模拟node01宕机，步骤省略，关机、挂起都可以！

NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES

mysql-pod-6cc889468b-g8cw6 1/1 Running 0 8m48s 10.244.2.2 node01

[[email protected] ~]# systemctl restart kubelet.service

//重启node02的kubelet服务

//接下来耐心等待pod的转移，可能需要差不多5分钟请耐性等待

[[email protected] ~]# kubectl get pod -o wide //可以看到pod已经运行在node02上

NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES

mysql-pod-6cc889468b-25ltd 1/1 Running 0 65s 10.244.1.2 node02

mysql-pod-6cc889468b-g8cw6 1/1 Terminating 0 19m 10.244.2.2 node01

[[email protected] ~]# kubectl exec -it mysql-pod-6cc889468b-25ltd -- mysql -u root -p123.com

//再次登录到pod中运行的mysql(注意：pod的名称)

//查看数据是否还存在，发现数据依然存在

mysql> select * from bjq.my_id;

+------+

| id |

+------+

| 9527 |

+------+

1 row in set (0.01 sec)

原文：https://blog.51cto.com/14306186/2522162