Simple CI/CD Demo

A simple Node.js web application demonstrating CI/CD concepts with Jenkins and Docker.

🎯 What This Project Demonstrates

• Continuous Integration: Automated testing on every code change
• Continuous Deployment: Automated deployment pipeline
• Jenkins Pipeline: Complete CI/CD workflow using Jenkinsfile
• Docker: Jenkins running in a containerized environment
• Automated Testing: Jest unit tests with CI integration

📁 Project Structure

simple-cicd-demo/
├── app.js              # Express.js web application
├── app.test.js         # Jest unit tests
├── package.json        # Node.js dependencies and scripts
├── Jenkinsfile         # Jenkins pipeline configuration
├── .gitignore          # Git ignore rules
└── README.md           # This documentation

🚀 Local Development

Prerequisites

• Node.js 18+ (we use 24.4.1 in CI)
• npm package manager

Quick Start

# Install dependencies
npm install

# Run tests
npm test

# Start the application
npm start

Available Scripts

• npm start - Start the Express server on port 3000
• npm test - Run Jest test suite

🌐 API Endpoints

• GET / - Returns hello world message with timestamp

  {
    "message": "Hello CI/CD World!",
    "version": "1.0.0",
    "timestamp": "2025-01-17T15:30:45.123Z"
  }

• GET /health - Health check endpoint

  {
    "status": "healthy",
    "uptime": 47.8329652
  }

🔧 CI/CD Pipeline

Our Jenkins pipeline includes these automated stages:

1. 📥 Checkout - Get latest code from GitHub
2. ⚙️ Setup - Verify Node.js 24.4.1 environment
3. 📦 Install Dependencies - Run npm install
4. 🧪 Run Tests - Execute Jest unit tests
5. 🏗️ Build - Prepare application for deployment
6. 🚀 Deploy to Staging - Simulate deployment process

Pipeline Configuration

The pipeline is defined in Jenkinsfile and includes:

• Automatic Node.js 24.4.1 installation
• Dependency caching
• Test result reporting
• Build artifacts
• Deployment simulation

🛠️ Technologies Used

Technology	Purpose
Node.js 24.4.1	Runtime environment
Express.js	Web framework
Jest	Testing framework
Supertest	HTTP testing utilities
Jenkins	CI/CD automation platform
Docker	Container platform for Jenkins
Git/GitHub	Version control and source hosting

📋 Setup Instructions

1. Clone Repository

git clone https://github.com/b95702041/simple-cicd-demo.git
cd simple-cicd-demo

2. Local Development

npm install
npm test
npm start

3. Jenkins Setup

1. Install Docker Desktop
2. Run Jenkins in Docker:

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

3. Access Jenkins: http://localhost:8080
4. Install NodeJS Plugin
5. Configure Node.js 24.4.1 tool
6. Create Pipeline job pointing to this repository

✅ Pipeline Results

Latest Build Status: ✅ SUCCESS

✅ Node.js: v24.4.1
✅ npm: v11.4.2
✅ Dependencies: 346 packages installed
✅ Tests: 2/2 passing
✅ Build: Completed successfully
✅ Deployment: Simulated successfully

🧪 Test Coverage

Test Suites: 1 passed, 1 total
Tests:       2 passed, 2 total
Snapshots:   0 total
Time:        1.672 s

Test Cases

• ✅ GET / returns correct hello message
• ✅ GET /health returns healthy status

📝 Learning Outcomes

This project demonstrates:

• Setting up a complete CI/CD pipeline from scratch
• Automated testing integration
• Docker containerization for development tools
• Git workflow with automated builds
• Jenkins pipeline configuration
• Node.js application development and testing

🔄 Workflow

1. Developer pushes code → GitHub repository
2. Jenkins detects changes → Triggers pipeline
3. Pipeline runs automatically → Tests, builds, deploys
4. Results reported → Success/failure notifications
5. Application deployed → Ready for use

🎓 Next Steps

To extend this project, consider:

• Adding more comprehensive tests
• Implementing real deployment to cloud platforms
• Adding code quality checks (linting, security scans)
• Setting up multiple environments (dev, staging, production)
• Adding notification integrations (Slack, email)
• Implementing blue-green deployments

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Created as a hands-on learning exercise for CI/CD concepts with Jenkins and Docker.

For questions or improvements, please open an issue or submit a pull request.