How to Change the Replicas for the Deployment — Kubernetes Assignment 3

You have been asked to:

● Use the previous deployment

● Change the replicas to 5 for the deployment

How to Change the Replicas for the Deployment — Kubernetes Assignment 3

Check the Git Hub Repository for this Assignment to Copy the Commands:

GitHub - visaltyagi/Kubernetes-Assignment-3: How to Change the Replicas for the Deployment …

Problem (1) Solution: Use the previous deployment

Before working on this assignment, you have to check the Kubernetes Assignment 1, where we have created a Kubernetes Cluster with 3 nodes & create 3 replica using the deployment.yaml file. Please check that assignment, now we will change the 3 replica to the 5 replicas.

We will use a new t2.medium machine with 3 replica node because t2.medium is chargeable, not possible to run the machine everytime.

Deployment with 3 Replicas

Problem (2) Solution: Change the replicas to 5 for the deployment

Step 1: Open the deployment.yaml file using this command:

nano deployment.yaml

Open the deployment.yaml file

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.16.1
        ports:
        - containerPort: 80

deployment.yaml file

Note: We are not using the sudo command because we are not working as a root user, only work as a normal user. Take care if you are working as a root user then use sudo otherwise start command without sudo. Otherwise, in the deployment creation, you will face the issue.

Step 2: Replace replicas as 3 to 5.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 5
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.16.1
        ports:
        - containerPort: 80

Change Replica Number from 3 to 5

Do “CTRL+X” to “Exit” & Type “Yes” to save the file. Press “Enter” from the keyboard after typing “Yes”.

Step 3: Now, again run the below-given command:

kubectl apply –f deployment.yaml

Run the below-given command to check the deployment status:

kubectl get deploy

A deployment with 5 replicas will be successfully created.

Step 4: If you run the below-given command, you will notice that 5 pods are successfully running.

kubectl get po

Five Running Pods

This means our replica have been successfully changed from 3 to 5.

More Assignments:

How to Create A NodePort Service & Deploy NGINX on It — Kubernetes Assignment 2

How to Change the NodePort Service to Cluster IP — Kubernetes Assignment 4

How to Deploy Ingress Service Using MiniKube in Kubernetes — Kubernetes Assignment 5

How to Deploy a Sample Website on Kubernetes Using Ingress — Kubernetes Case Study