Pod PV and PVC implement automatic migration, MySQL data persistence

MySQL data persistence based PV and PVC

Demonstrates how to provide persistent storage for the MySQL database, the following steps:

1. Creating PV and PVC.
2. Deploy MySQL.
3. Add data to MySQL.
4. Fault simulation node goes down, Kubernetes MySQL will automatically migrate to another node.
5. Verify data consistency.

The first step: a control node deployment NFS

[root@ken1 ~]# cat /etc/exports
/ken/mysql *(rw,no_root_squash)

Note: This is not meant to be added no_root_squash reduce root privileges, without this being given as follows:

chown: changing ownership of '/var/lib/mysql/': Operation not permitted

When no_root_squash access the shared directory, if the user is root access to the shared directory also have root privileges

root_squash if access to the shared directory is the root user's permissions on the shared directory permissions will be compressed into a user's right nfsnobody

Whether you all_squash user access to the shared directory of who they are, it must be compressed to nfsnobody user permissions

Step two: First create PV and PVC, configuration is as follows:

pv.yml

[root@ken1 ~]# cat pv.yml 
apiVersion: v1
kind: PersistentVolume
metadata:
 name: mypv
spec:
 capacity:
 storage: 1Gi
 accessModes: 
 - ReadWriteMany
 nfs:
 path: /ken
 server: 192.168.64.11

pvc.yml

[root@ken1 ~]# cat pvc.yml 
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
 name: mypvc
spec:
 volumeName: mypv
 accessModes:
 - ReadWriteMany
 resources:
 requests:
 storage: 1Gi

Step 3: Create pv and pvc

[root@ken1 ~]# kubectl apply -f pv.yml 
persistentvolume/mypv unchanged
[root@ken1 ~]# kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
mypv 1Gi RWX Retain Available 8d
[root@ken1 ~]# kubectl apply -f pvc.yml 
persistentvolumeclaim/mypvc created
[root@ken1 ~]# kubectl get pvc
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
mypvc Bound mypv 1Gi RWX 3s

Step Four: Next to deploy MySQL, the configuration file as follows

[root@ken1 ~]# cat mysql.yml
apiVersion: v1
kind: Service
metadata:
 name: mysql-svc
spec:
 type: NodePort
 selector:
 run: mysql
 ports:
 - port: 80
 targetPort: 3306
 NodePort: 3306
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
 name: mysql
spec:
 template:
 metadata:
 labels:
 run: mysql
 spec:
 containers:
 - name: mysql
 image: mysql
 imagePullPolicy: IfNotPresent
 env:
 - name: MYSQL_ROOT_PASSWORD
 value: ken 
 ports:
 - name: mysql
 containerPort: 3306
 volumeMounts:
 - name: mysql
 mountPath: /var/lib/mysql
 volumes:
 - name: mysql
 persistentVolumeClaim:
 claimName: mypvc

Step five: View pod

[root@ken1 ~]# kubectl get po -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
mysql-587dbd4dd6-79tn5 1/1 Running 0 9m20s 10.244.1.60 ken2 <none> <none>

Step Six: Create a database login database ken

[root@ken1 ~]# kubectl exec -it mysql-587dbd4dd6-79tn5 bash
root@mysql-587dbd4dd6-79tn5:/# mysql -uroot -pken
mysql> create database ken;
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| ken |
| mysql |
| performance_schema |
| sys |
+--------------------+
5 rows in set (0.00 sec)

Step Seven: run off the pod ken2 node simulated fault

poweroff

Eighth step: after a period of time the pod k8s mobile node to ken3

[root@ken1 ~]# kubectl get po -o wide -w
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
mysql-587dbd4dd6-79tn5 1/1 Running 0 14m 10.244.1.60 ken2 <none> <none>
mysql-587dbd4dd6-79tn5 1/1 Terminating 0 18m 10.244.1.60 ken2 <none> <none>
mysql-587dbd4dd6-gxnpq 0/1 Pending 0 0s <none> <none> <none> <none>
mysql-587dbd4dd6-gxnpq 0/1 Pending 0 0s <none> ken3 <none> <none>
mysql-587dbd4dd6-gxnpq 0/1 ContainerCreating 0 0s <none> ken3 <none> <none>
mysql-587dbd4dd6-gxnpq 1/1 Running 0 3s 10.244.2.139 ken3 <none> <none>

Step 9: Verify database consistency in the login node data ken3

[root@ken3 ~]# docker exec -it 2aaf1b234ebf bash
root@mysql-587dbd4dd6-gxnpq:/# mysql -uroot -pken
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| ken |
| mysql |
| performance_schema |
| sys |
+--------------------+
5 rows in set (0.02 sec)

MySQL service recovery, data also intact.