📦 Simple Node.js Application – Jenkins CI/CD Demo

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📌 Project Overview

This project demonstrates a complete CI/CD pipeline setup using Jenkins for a simple Node.js application.

It’s designed to help:

• 🧑‍💻 DevOps beginners
• 🧪 Students
• 🎯 Interview candidates

💡 While the app is intentionally simple, the goal is to learn Jenkins automation, Docker containerization, and real-world DevOps flow — essential for junior DevOps roles.

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🚀 What You’ll Learn

✅ Connect Jenkins to a GitHub repo
✅ Automate builds, tests, and deployments using a Jenkinsfile
✅ Containerize apps using Docker
✅ Trigger builds via GitHub push or Jenkins UI

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🛠️ Tech Stack

Tool	Purpose
Node.js	Application Runtime
npm	Dependency Management
Jenkins	Continuous Integration Tool
Docker	Containerization
GitHub	Source Code Hosting

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🧪 Quick Start Guide

🔁 1. Clone the Repository

git clone https://github.com/<YOUR-USERNAME>/<YOUR-REPO-NAME>.git
cd <YOUR-REPO-NAME>

💻 2. Run Locally (Optional)

npm install
npm start

🔗 Visit: http://localhost:3000

🐳 3. Build Docker Image (Optional)

docker build -t simple-node-app .
docker run -p 3000:3000 simple-node-app

👷 Jenkins CI/CD Pipeline

🔄 Pipeline Flow

GitHub Push ➜ Jenkins Trigger ➜ Checkout ➜ Install ➜ Test ➜ Docker Build ➜ Run Container

🧱 Pipeline Stages (from Jenkinsfile)

Checkout Pull latest code from GitHub

Install Run npm install to install dependencies

Test Run tests using npm test (⚠️ Test failures won’t stop pipeline (|| true used) )

Docker Build Build Docker image from Dockerfile

Run Container Deploy container on port 3000

🧰 How to Use This Project

🔧 Jenkins Setup

• Install Jenkins on your system or use Docker.

• Install required plugins:

• ✅ Docker Pipeline

• ✅ Git

• ✅ NodeJS

• Configure Jenkins:

• Connect Jenkins to your GitHub repository

• Create a new Pipeline job and point it to this repo

• Ensure Jenkins agent can run Docker

⚙️ Trigger Builds

• Automatically: via GitHub webhook or SCM polling

• Manually: use “Build Now” in Jenkins UI