CI/CD pipeline for Express apps - Mini Project: Build & Apply

CI/CD Pipeline for Express Apps

📖 Scenario: You are a developer working on a simple Express.js web application. You want to automate the process of testing and deploying your app whenever you make changes. This project will guide you through setting up a basic Continuous Integration and Continuous Deployment (CI/CD) pipeline using GitHub Actions.

🎯 Goal: Build a CI/CD pipeline that automatically installs dependencies, runs tests, and deploys the Express app when code is pushed to the main branch.

📋 What You'll Learn

Create a basic Express.js app with a test script

Add a GitHub Actions workflow configuration file

Configure the workflow to install dependencies and run tests

Add a deployment step that runs only on the main branch

💡 Why This Matters

🌍 Real World

Automating testing and deployment saves time and reduces errors when updating web applications.

💼 Career

CI/CD pipelines are essential skills for developers and DevOps engineers to ensure reliable software delivery.

1

Create a basic Express app with a test script

Create a file called app.js with a simple Express server that listens on port 3000 and responds with "Hello World" at the root URL. Also, create a package.json file with a test script that runs echo \"Test passed!\".

Express

# Create app.js with Express server and package.json with test script
# Your code here

Need a hint?

Use express() to create the app and app.get('/', ...) to handle the root route. The test script in package.json should just echo a success message.

2

Add GitHub Actions workflow file

Create a file called .github/workflows/nodejs.yml with a workflow that triggers on push events to any branch. Define a job called build that runs on ubuntu-latest.

Express

const express = require('express');
const app = express();
const port = 3000;

app.get('/', (req, res) => {
  res.send('Hello World');
});

app.listen(port, () => {
  console.log(`Server running on port ${port}`);
});

// package.json content:
// {
//   "name": "express-app",
//   "version": "1.0.0",
//   "main": "app.js",
//   "scripts": {
//     "test": "echo \"Test passed!\""
//   },
//   "dependencies": {
//     "express": "^4.18.2"
//   }
// }

# Create .github/workflows/nodejs.yml with push trigger and build job on ubuntu-latest
# Your code here

Need a hint?

The workflow file should start with name and on: [push]. Define a job named build that runs on ubuntu-latest.

3

Configure workflow to install dependencies and run tests

In the build job of nodejs.yml, add steps to check out the code, set up Node.js version 18, install dependencies with npm install, and run tests with npm test.

Express

const express = require('express');
const app = express();
const port = 3000;

app.get('/', (req, res) => {
  res.send('Hello World');
});

app.listen(port, () => {
  console.log(`Server running on port ${port}`);
});

// package.json content:
// {
//   "name": "express-app",
//   "version": "1.0.0",
//   "main": "app.js",
//   "scripts": {
//     "test": "echo \"Test passed!\""
//   },
//   "dependencies": {
//     "express": "^4.18.2"
//   }
// }

# Add steps to nodejs.yml to checkout code, setup Node.js 18, install dependencies, and run tests
# Your code here

Need a hint?

Use actions/checkout@v3 to get the code, actions/setup-node@v3 with node-version: '18' to set Node.js, then run npm install and npm test.

4

Add deployment step for main branch

In the build job of nodejs.yml, add a step that runs only when the branch is main. This step should print Deploying app... using echo command.

Express

const express = require('express');
const app = express();
const port = 3000;

app.get('/', (req, res) => {
  res.send('Hello World');
});

app.listen(port, () => {
  console.log(`Server running on port ${port}`);
});

// package.json content:
// {
//   "name": "express-app",
//   "version": "1.0.0",
//   "main": "app.js",
//   "scripts": {
//     "test": "echo \"Test passed!\""
//   },
//   "dependencies": {
//     "express": "^4.18.2"
//   }
// }

# Add deploy step that runs only on main branch
# Your code here

Need a hint?

Add a step with name: Deploy and use if: github.ref == 'refs/heads/main' to run only on main branch. The command should be echo "Deploying app...".