Automating Deployments Using Jenkins & AWS S3

0 Required Tools & Accounts

Ensure you have the following ready before starting the deployment lab.

1 Setting up our Jenkins Robot

We are going to run Jenkins inside a Docker Container. Open your terminal and paste this command to start it up:

docker run -d --name jenkins-server -p 8080:8080 -p 50000:50000 -v jenkins_data:/var/jenkins_home jenkins/jenkins:lts

Jenkins secures itself on the first boot. You need the initial admin password to proceed. Run this to view the logs:

docker logs jenkins-server

2 Giving Jenkins the Right Tools

By default, Jenkins doesn't know how to talk to Amazon Web Services. We need to install the AWS Command Line tool directly inside our container.

# Step 1: Drop into the container's terminal as root user
docker exec -u root -it jenkins-server /bin/bash

# Step 2: Install the AWS CLI package
apt-get update && apt-get install -y awscli

# Step 3: Exit back to your host machine
exit

3 Setting Up AWS (The Destination)

We need a place to put our website, and we need to give Jenkins a secure "ID Badge" to enter our AWS account.

4 Linking AWS to Jenkins

Now we hand that ID badge over to Jenkins securely so it isn't hardcoded in our scripts.

1. Open your Jenkins dashboard at http://localhost:8080.
2. Navigate to Manage Jenkins -> Credentials.
3. Click on (global), then click + Add Credentials.
4. Set Kind to Username with password.
5. Username: Paste your AWS Access Key ID.
6. Password: Paste your AWS Secret Access Key.
7. ID: Type exactly aws-credentials (We will reference this ID in code).
8. Click Create.

5 Writing the Automation Instructions

Create a new Pipeline job in Jenkins, configure it to Poll SCM every minute (* * * * *), and paste this Groovy script into the Pipeline box. Make sure to replace your GitHub URL and Bucket Name!

pipeline {
    agent any

    environment {
        // Set this to the region where you created your S3 bucket
        AWS_DEFAULT_REGION = 'ap-south-1' 
    }

    stages {
        stage('Grab Code from GitHub') {
            steps {
                // Jenkins downloads the latest code from your main branch
                git branch: 'main', url: 'https://github.com/YourUsername/YourRepoName.git'
            }
        }

        stage('Upload to AWS S3') {
            steps {
                // Jenkins uses the secure credentials we saved earlier
                withCredentials([usernamePassword(credentialsId: 'aws-credentials', passwordVariable: 'AWS_SECRET_ACCESS_KEY', usernameVariable: 'AWS_ACCESS_KEY_ID')]) {
                    sh '''
                        echo "Starting website upload..."
                        
                        # Syncs our code files to the AWS bucket, skipping the hidden .git folder
                        aws s3 sync . s3://your-actual-bucket-name --exclude ".git/*" --delete
                        
                        echo "Upload complete! Your website is updated."
                    '''
                }
            }
        }
    }
}

6 The Final Test (Go Live)