1、搭建nfs存储

[root@docker-k8s01 ~]# yum -y install nfs-utils

[root@docker-k8s01 ~]# mkdir /nfsdata/mysql -p

[root@docker-k8s01 ~]# cat /etc/exports

/nfsdata *(rw,sync,no_root_squash)

[root@docker-k8s01 ~]# systemctl restart nfs-server

[root@docker-k8s01 ~]# systemctl enable rpcbind

[root@docker-k8s01 ~]# systemctl enable nfs-server

[root@docker-k8s01 ~]# showmount -e

Export list for docker-k8s01:

/nfsdata *

2、创建PV

//编写pv的yaml文件

kind: PersistenVolume

apiVersion: v1

metadata:

name: mysql-pv

spec:

accessModes:

- ReadWriteOnce

capacity:

storage: 1Gi

persistentVolumeReclaimPolicy: Retain

storageClassName: nfs

nfs:

path: /nfsdata/mysql

server: 192.168.171.151

//执行yaml文件

[root@docker-k8s01 mysql]# kubectl apply -f mysql-pv.yaml

3、创建PVC

//编写PVC的yaml文件

kind: PersistentVolumeClaim

apiVersion: v1

metadata:

name: mysql-pvc

spec:

accessModes:

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

resources:

requests:

storage: 1Gi

storageClassName: nfs //这里指定关联的PV名称

[root@docker-k8s01 mysql]# kubectl apply -f mysql-pvc.yaml

4、确认pv及pvc的状态

//可以看到pv及pvc的状态都是Bound

[root@docker-k8s01 mysql]# kubectl get pv

NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE

mysql-pv 1Gi RWO Retain Bound default/mysql-pvc nfs 6m21s

[root@docker-k8s01 mysql]# kubectl get pvc

NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE

mysql-pvc Bound mysql-pv 1Gi RWO nfs 2m4s

5、创建pod+svc(service)

这个pod是提供的MySQL服务，并将其映射到宿主机，可以做和client端通信

//编写deployment及service的yaml文件

---

apiVersion: extensions/v1beta1

kind: Deployment

metadata:

name: mysql

spec:

selector:

matchLabels:

app: mysql

template:

metadata:

labels:

app: mysql

spec:

containers:

- name: mysql

image: mysql:5.7

env: //配置变量，设置mysql的密码

- name: MYSQL_ROOT_PASSWORD

value: 123.com

ports:

- containerPort: 3306

volumeMounts:

- name: mysql-persistent-storage

mountPath: /var/lib/mysql //MySQL容器的数据都是存在这个目录的，要对这个目录做数据持久化

volumes:

- name: mysql-persistent-storage

persistentVolumeClaim:

claimName: mysql-pvc //指定pvc名称

---

apiVersion: v1

kind: Service

metadata:

name: mysql

spec:

type: NodePort

ports:

- port: 3306

targetPort: 31111

selector:

app: mysql

[root@docker-k8s01 mysql]# kubectl apply -f mysql-pod.yaml

//确定pod运行正常

[root@docker-k8s01 mysql]# kubectl get pod -w

NAME READY STATUS RESTARTS AGE

mysql-6d898f8bcb-fc7bb 1/1 Running 0 60s

6、进入MySQL数据库，添加测试数据

mysql> create database test;

mysql> use test

mysql> create table my_id(id int(11));

mysql> insert my_id values(1234);

mysql> select * from test.my_id; //确定数据添加成功

+------+

| id |

+------+

| 1234 |

+------+

7、手动删除节点上的容器，验证数据库内的数据是否还存在

//查看Pod运行在哪个节点

[root@docker-k8s01 mysql]# kubectl get pod -o wide

NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES

mysql-6d898f8bcb-fc7bb 1/1 Running 0 7m6s 10.244.1.2 docker-k8s02

[root@docker-k8s02 ~]# docker ps // 查看mysql容器的id

//删除mysql容器

[root@docker-k8s02 ~]# docker rm -f 7ba3f9d9ad35

//由于Deployment的保护策略，当删除容器后，它会根据pod的yaml文件生成一个新的容器，但新容器的ID号就变了

//回到master节点，登录到数据库，查看数据是否还存在

[root@docker-k8s01 mysql]# kubectl exec -it mysql-6d898f8bcb-fc7bb -- mysql -uroot -p123.com

mysql> select * from test.my_id;

+------+

| id |

+------+

| 1234 |

+------+

1 row in set (0.01 sec)

证明:当使用PV来做数据持久化的话，容器的新陈代谢并不会造成丢失数据的。

8、模拟MySQL容器所在的节点宕机，验证数据是否会丢失

//查看容器所在节点

[root@docker-k8s01 mysql]# kubectl get pod -o wide

NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES

mysql-6d898f8bcb-fc7bb 1/1 Running 0 13m 10.244.1.2 docker-k8s02

//将docker-k8s02节点宕机，动态查看Pod的状态

//大概node01关机五分钟左右，可以看到pod就被转移到node02上运行了

[root@docker-k8s01 ~]# kubectl get pod -w

NAME READY STATUS RESTARTS AGE

mysql-6d898f8bcb-fc7bb 1/1 Running 0 22m

mysql-6d898f8bcb-fc7bb 1/1 Running 0 22m

mysql-6d898f8bcb-fc7bb 1/1 Terminating 0 27m

mysql-6d898f8bcb-2h47v 0/1 Pending 0 0s

mysql-6d898f8bcb-2h47v 0/1 Pending 0 0s

mysql-6d898f8bcb-2h47v 0/1 ContainerCreating 0 0s

mysql-6d898f8bcb-2h47v 1/1 Running 0 33s

9、client端访问MySQL数据库

因为我们在创建pod的yaml文件中，将其svc的端口映射类型是nodeport，所以，我们是可以通过访问群集内的任意主机的31111端口(yaml文件中自定义的端口)来登录到数据库的。

[root@docker-k8s01 ~]# mysql -uroot -p123.com -h 192.168.171.151 -P 31111

MySQL [(none)]> select * from test.my_id; #查看数据

+------+

| id |

+------+

| 1234 |

+------+

1 row in set (0.01 sec)