DevOps CI/CD Pipeline with Jenkins, Docker & AWS ECR 🚀

This repository demonstrates a real-world DevOps CI/CD pipeline using Jenkins, Docker, and AWS ECR, deployed on a single EC2 instance.
It’s designed for learning purposes, showing how code from GitHub can automatically be built, pushed to ECR, and deployed as a container.

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🏗 Architecture

GitHub → Jenkins (EC2) → Docker → AWS ECR → EC2 (runs container)

• Jenkins: Installed on EC2, orchestrates the pipeline.
• Docker: Containerizes the application.
• AWS ECR: Stores Docker images for deployment.
• EC2: Hosts both Jenkins and the running container.

⚡ Simple, production-like setup for learning CI/CD without using EKS or Kubernetes.

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⚙️ Requirements

• Ubuntu 22.04 EC2 instance
• Docker installed
• Jenkins installed
• AWS CLI configured with credentials
• AWS ECR repository

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📝 Setup Instructions

1️⃣ Launch EC2

• OS: Ubuntu 22.04
• Instance type: t2.micro
• Storage: 20 GB
• Security Group: Open ports
  • 22 (SSH)
  • 8080 (Jenkins)
  • 80 (App)

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2️⃣ Connect to EC2

ssh -i your-key.pem ubuntu@<your-ec2-public-ip>

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3️⃣ Install Required Software

sudo apt update -y

# Docker
sudo apt install docker.io -y
sudo systemctl start docker
sudo systemctl enable docker
sudo usermod -aG docker ubuntu

# Java for Jenkins
sudo apt install openjdk-17-jdk -y

# Jenkins
curl -fsSL https://pkg.jenkins.io/debian-stable/jenkins.io-2023.key | sudo tee /usr/share/keyrings/jenkins-keyring.asc > /dev/null
echo deb [signed-by=/usr/share/keyrings/jenkins-keyring.asc] https://pkg.jenkins.io/debian-stable binary/ | sudo tee /etc/apt/sources.list.d/jenkins.list > /dev/null
sudo apt update
sudo apt install jenkins -y
sudo systemctl start jenkins

# AWS CLI
sudo apt install unzip -y
curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip"
unzip awscliv2.zip
sudo ./aws/install

# Permissions
sudo usermod -aG docker jenkins
sudo systemctl restart jenkins

# Verify
docker --version
aws --version

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4️⃣ Setup Jenkins UI

• Open: http://<EC2-IP>:8080
• Get initial password:

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

• Install suggested plugins
• Create admin user

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5️⃣ Configure AWS CLI

aws configure

Enter:

• Access Key ID
• Secret Access Key
• Default region (e.g., us-east-1)

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6️⃣ Create ECR Repository

aws ecr create-repository --repository-name devops-app

Copy repository URL:
<account-id>.dkr.ecr.<region>.amazonaws.com/devops-app

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7️⃣ Prepare GitHub Repository

Include:

• Jenkinsfile
• Dockerfile
• Application code (app.js, package.json)

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8️⃣ Create Jenkins Pipeline

• Jenkins → New Item → Pipeline → Name: devops-cicd
• Pipeline script from SCM → Git → URL: your repo → Script Path: Jenkinsfile

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9️⃣ Jenkinsfile Example

pipeline {
    agent any

    environment {
        AWS_REGION = "us-east-1"
        ECR_REPO = "<your-ecr-repo>"
        IMAGE_NAME = "devops-app"
        CONTAINER_NAME = "app"
    }

    stages {

        stage('Clone') {
            steps {
                git '<your-github-repo-url>'
            }
        }

        stage('Build Image') {
            steps {
                sh 'docker build -t $IMAGE_NAME .'
            }
        }

        stage('ECR Login') {
            steps {
                sh '''
                aws ecr get-login-password --region $AWS_REGION | \
                docker login --username AWS --password-stdin $ECR_REPO
                '''
            }
        }

        stage('Tag Image') {
            steps {
                sh 'docker tag $IMAGE_NAME:latest $ECR_REPO:latest'
            }
        }

        stage('Push Image') {
            steps {
                sh 'docker push $ECR_REPO:latest'
            }
        }

        stage('Deploy') {
            steps {
                sh '''
                docker stop $CONTAINER_NAME || true
                docker rm $CONTAINER_NAME || true
                docker run -d -p 80:3000 --name $CONTAINER_NAME $ECR_REPO:latest
                '''
            }
        }
    }
}

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🔧 10️⃣ Run Pipeline

• Click Build Now in Jenkins
• Pipeline will:
  1. Pull code from GitHub
  2. Build Docker image
  3. Push image to ECR
  4. Deploy container on EC2

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🌐 11️⃣ Test Deployment

Open in browser:
http://<EC2-IP>
You should see your application running.

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🔁 12️⃣ Automate GitHub Pushes

• GitHub → Settings → Webhooks
• Payload URL: http://<EC2-IP>:8080/github-webhook/
• Content type: application/json
• Events: Just the push event

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📸 Screenshots

1. Jenkins dashboard showing pipeline devops-cicd

2. Pipeline stage view with all stages green

3. Build logs of a successful run

4. EC2 terminal showing docker ps with running container

5. Browser showing app running at http://<EC2-IP>

6. AWS ECR console showing pushed image

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🗒 Notes

• This project is for learning Jenkins and CI/CD pipelines.
• No complex orchestration like EKS/Kubernetes — simplicity for understanding pipeline flow.
• Can be recreated on any EC2 for practice.

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🎯 Key Learning Outcomes

• Jenkins pipeline creation & stages
• Docker image build and management
• AWS ECR integration
• Continuous deployment to EC2
• GitHub webhook triggers

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