Step-by-Step Guide: Installing Jenkins on AWS EC2 and Deploying to Kubernetes

````markdown name=installing-jenkins-on-aws-ec2.md

In this guide, we'll go through the detailed steps to set up Jenkins on an AWS EC2 instance, install necessary plugins, and configure Jenkins for deploying applications to a Kubernetes cluster.

1️⃣ Install Jenkins on AWS EC2

Step 1: Update Your System

First, let's make sure your system is up to date. Run the following command to update your package list and upgrade your installed packages:

sh
sudo apt update && sudo apt upgrade -y

✅ This ensures your system is up-to-date.

Step 2: Install Java (Required for Jenkins)

Jenkins requires Java to run. Install OpenJDK 11 by running:

sh
sudo apt install openjdk-11-jdk -y

Verify the Java installation:

sh
java -version

✅ Expected output:

plaintext
openjdk version "11.0.xx"

Step 3: Install Jenkins

Add the Jenkins repository:

sh
wget -q -O - https://pkg.jenkins.io/debian-stable/jenkins.io.key | sudo tee /etc/apt/trusted.gpg.d/jenkins.asc > /dev/null

Add the Jenkins package source:

sh
echo "deb http://pkg.jenkins.io/debian-stable binary/" | sudo tee /etc/apt/sources.list.d/jenkins.list > /dev/null

Update the package list and install Jenkins:

sh
sudo apt update
sudo apt install jenkins -y

Step 4: Start and Enable Jenkins

Start the Jenkins service:

sh
sudo systemctl start jenkins

Enable Jenkins to start on boot:

sh
sudo systemctl enable jenkins

Check the status of Jenkins:

sh
sudo systemctl status jenkins

✅ You should see "active (running)".

Step 5: Access Jenkins Dashboard

Find your EC2 public IP:

sh
curl ifconfig.me

Now, open your browser and go to:

plaintext
http://<your-ec2-public-ip>:8080

Jenkins should be running! 🎉

Step 6: Unlock Jenkins

Find the admin password:

sh
sudo cat /var/lib/jenkins/secrets/initialAdminPassword

Copy and paste it into the Jenkins setup page. Click "Install suggested plugins" and create an admin user.

✅ Now you have Jenkins running! 🎯

2️⃣ Install Kubernetes and Docker Plugins in Jenkins

Jenkins needs plugins to communicate with Kubernetes.

Step 1: Install Docker & Kubernetes Plugins

Go to Jenkins Dashboard → Manage Jenkins → Manage Plugins. Search for and install the following plugins:

• Docker
• Kubernetes
• Pipeline
• GitHub

After installing the plugins, restart Jenkins.

3️⃣ Configure Jenkins to Deploy to Kubernetes

Jenkins will automate deployments to your Kubernetes cluster.

Step 1: Create a Service Account in Kubernetes

On your EC2 instance, run:

sh
kubectl create serviceaccount jenkins
kubectl create clusterrolebinding jenkins --clusterrole=cluster-admin --serviceaccount=default:jenkins

Step 2: Get Kubernetes API Token

Run the following command to get the Kubernetes API token:

sh
kubectl get secret $(kubectl get serviceaccount jenkins -o jsonpath="{.secrets[0].name}") -o jsonpath="{.data.token}" | base64 --decode

Copy this token.

Step 3: Configure Jenkins Credentials

Go to Jenkins Dashboard → Manage Jenkins → Manage Credentials. Under Global Credentials, add:

• Type: Kubernetes Configuration (Secret Text)
• Secret: Paste the token from Step 2
• ID: k8s-api-token

4️⃣ Create a Jenkins Pipeline to Deploy to Kubernetes

Go to Jenkins Dashboard → New Item → Pipeline. Name it K8s-Deployment and choose Pipeline.

In the Pipeline Script section, paste the following script:

groovy
pipeline {
    agent any

    environment {
        KUBECONFIG = credentials('k8s-api-token')
    }

    stages {
        stage('Checkout Code') {
            steps {
                git 'https://github.com/YOUR_GITHUB_REPO.git'  // Replace with your repo
            }
        }

        stage('Build Docker Image') {
            steps {
                sh 'docker build -t myapp:latest .'
            }
        }

        stage('Push Image to Docker Hub') {
            steps {
                withDockerRegistry([credentialsId: 'docker-hub', url: 'https://index.docker.io/v1/']) {
                    sh 'docker tag myapp:latest YOUR_DOCKER_USERNAME/myapp:latest'
                    sh 'docker push YOUR_DOCKER_USERNAME/myapp:latest'
                }
            }
        }

        stage('Deploy to Kubernetes') {
            steps {
                sh 'kubectl apply -f deployment.yaml'
            }
        }
    }
}

✅ Replace:

• YOUR_GITHUB_REPO with your GitHub repository
• YOUR_DOCKER_USERNAME with your Docker Hub username

5️⃣ Create Kubernetes Deployment Manifest

Create a file named deployment.yaml:

sh
nano deployment.yaml

Paste the following content:

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

✅ Replace YOUR_DOCKER_USERNAME/myapp:latest with your Docker Hub image.

Apply the deployment:

sh
kubectl apply -f deployment.yaml

✅ Your app is now running on Kubernetes! 🎉

🎯 Final Test

Run the following commands to verify the deployment:

sh
kubectl get pods
kubectl get deployments

✅ You should see your myapp deployment running.

Congratulations! You've successfully set up Jenkins on AWS EC2 and configured it to deploy to a Kubernetes cluster. Happy CI/CD! 🚀

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