How to Deploy an Application on a Kubernetes Cluster

This document provides step-by-step instructions for deploying an application on a Kubernetes cluster.

Step 1: Prerequisites

Ensure the following are set up before proceeding:

• Kubernetes cluster is up and running.

• kubectl is configured to interact with your cluster.

• Docker image of your application is available in a container registry (e.g., Docker Hub).

• Proper access to the cluster and namespace (if using role-based access control).

First of all deploy a kubernetes cluster download its config file and

export it on your local server with command:-

export KUBECONFIG=test.yml

After that install the kubectl packages with command:-

snap install kubectl --classic

Kubectl get nodes

You will see your connected nodes on server

Step 2: Create a Deployment YAML

Create a YAML file for your application’s Deployment. Below is an

example for an application using the nginx image:

Save this file as deployment.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
        - name: nginx
          image: nginx:latest
          ports:
            - containerPort: 80

Step 3: Create a Service YAML

To expose your application, create a Service YAML file. For a

LoadBalancer:

Save this file as service.yaml:

apiVersion: v1
kind: Service
metadata:
  name: nginx-service
spec:
  selector:
    app: nginx
  ports:
    - protocol: TCP
      port: 80
      targetPort: 80
  type: LoadBalancer

Step 4: Deploy Resources to Kubernetes

Apply the Deployment YAML:

kubectl apply -f deployment.yaml

Apply the Service YAML:

kubectl apply -f service.yaml

Step 5: Verify the Deployment

Check the status of your Deployment:

kubectl get deployments

Example output:

NAME READY UP-TO-DATE AVAILABLE AGE\

nginx-deployment 2/2 2 2 5m

Check the status of the Service:

kubectl get services

Example output:

NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE\

nginx-service LoadBalancer 10.96.22.221 103.189.88.232 80:30080/TCP 5m

Step 6: Access the Application

If you created a LoadBalancer Service, find the EXTERNAL-IP from the

Service output.

Open your browser or use curl to access the application:

http://EXTERNAL-IP:80

Example output:

If successful, you should see the application’s welcome page (e.g.,

Nginx default page).

Step 7: Troubleshooting

Check pod status if something isn't working:

kubectl get pods

Example output:

NAME READY STATUS RESTARTS AGE\

nginx-deployment-7c79c4bf97-w8md8 1/1 Running 0 5m

Describe the pod for detailed logs:

kubectl describe pod POD-NAME

Review logs of the pod:

kubectl logs <POD-NAME>

Check the Events section in your Service or Deployment description:

kubectl describe svc nginx-service

kubectl describe deployment nginx-deployment

Step 8: Cleanup (Optional)

If you want to remove the deployment and service:

Delete the Deployment:

kubectl delete -f deployment.yaml

Delete the Service:

kubectl delete -f service.yaml

Thank You!