K8s — How To Deploy MySQL Using Persistent Volume

Hello Readers !!! In this blog we’ll see How To Deploy MySQL Using Persistent Volume . You may found this article quite interesting while performing. Hope you’ll enjoy learning this new topic .

So let’s Get Start !!!

INTRODUCTION

This MySQL application deployment demonstrates how to provide persistent storage for a MySQL database.

Prerequisites

• A K8s cluster with AWS EFS CSI driver installed
• A ready to use AWS EFS file system

Steps

To deploy MySQL using Persistent Volume one should follow these steps to do so :

1. Create Storage Class
2. Create PVC (PersistentVolumeClaim) for MySQL.
3. Deploy MySQL (Deployment and Service).
4. Add data to MySQL.
5. Simulate a node failure, and K8s automatically migrates MySQL to other nodes.

Now let’s see How we can perform the above steps one by one :

STEP-1 Create Storage Class

To create persistent volumes dynamically, you need to define a StorageClass first. Below the the sample YAML file to create storageclass:

# storage_class.yml

kind: StorageClass

apiVersion: storage.k8s.io/v1

metadata:

  name: efs-sc

provisioner: k8s.io/minikube-hostpath 

volumeBindingMode: Immediate

parameters:

 type: gp2 # This configures SSDs (recommended).

allowVolumeExpansion: true

reclaimPolicy: Retain

  

I will perform all this under MySQL namespace. So create namespace by running the following command:

kubectl create ns mysql

Create the above StorageClass by running the following command:

kubectl apply -f storageclass.yaml -n mysql


kubectl get storageclass -n mysql

STEP-2 Create PVC for MySQL

Now you should create pvc for mysql . The yaml file looks like :

# mysql-pvc.yml

apiVersion: v1

kind: PersistentVolumeClaim

metadata:

  name: mysql-pvc

spec:

  accessModes:

    - ReadWriteMany

  storageClassName: efs-sc

  resources:

    requests:
    
      storage: 5Gi

Create the PVC by :

kubectl create -f mysqlpvc.yaml -n mysql

kubectl get pvc -n mysql 

STEP – 3 Deploy MySQL App

Now, let’s deploy the MySQL application, the YAML definition is as follows:

# mysql-deployment.yml

apiVersion: apps/v1

kind: Deployment

metadata:

  name: mysql

spec:

  replicas: 1

  selector:

    matchLabels:

      app: mysql

  template:

    metadata:

      labels:

        app: mysql

    spec:

      containers:

      - name: mysql

        image: mysql:5.7

        securityContext:

          runAsUser: 1000

          allowPrivilegeEscalation: false

        env:

        - name: MYSQL_ROOT_PASSWORD

          value: password

        ports:

        - containerPort: 3306

          name: mysql

        volumeMounts:

        - name: mysql-persistent-storage

          mountPath: /var/lib/mysql
      volumes:

      - name: mysql-persistent-storage

        persistentVolumeClaim:
        
          claimName: mysql-pvc

Deploy this deployment file by running the command:

kubectl create -f mysql-deployment.yaml -n mysql

kubectl get pods -n mysql 

kubectl logs mysql-5d646c5467-9ghgd -n mysql

You we’ll see something like this :

STEP – 4 Deploy MySQL Service

Next step is to deploy the mysql service . The mysql-service.yaml looks like:

apiVersion: v1

kind: Service

metadata:

  name: mysql

spec:

  ports:

  - port: 3306

  selector:
  
    app: mysql

Deploy this yaml by running the following command:

kubectl create -f mysql-service.yml -n mysql

STEP – 5 Simulate Node Failure

Now MySQL is deployed to node , and we can accesses the MySQL service through the client mysql. Run the following command:

kubectl run -it --rm --image=mysql:5.7 --restart=Never mysql-client -- mysql
 
-h mysql -ppassword

Let’s update the database and add some data:

let’s shutdown the mysql database as:

STEP – 6 Verfiy Consistency

Let’s shut down the node and yes we have done .

CONCLUSION

Here in this blog we have seen How To Deploy MySQL Using Persistent Volume .Hope you learn something new and interesting . In case of any problem you can ask me .

Thankyou

Keep Learning !!!

REFERENCE

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