CI/CD Pipeline for a Node.js App: Automated Testing and Deployment to Render

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Introduction

Are you looking to streamline your development process? Setting up a CI/CD pipeline can be a game-changer, especially for Node.js applications. This guide will walk you through creating a beginner-friendly CI/CD pipeline using GitLab to automate testing and deployment for a simple Node.js app. By the end, you’ll have a robust DevOps workflow that enables you to ship code faster and safer.

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📁 Folder Structure

Here’s how your project folder should look:

node-ci-cd-app/
├── .gitlab-ci.yml          # GitLab pipeline config
├── package.json
├── .gitignore
├── app.js                  # Main server file
├── routes/
│   └── ping.js             # Example route
├── tests/
│   └── ping.test.js        # Test for the ping route
└── README.md

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✅ Step 1: Create a Simple Node.js App

1. Initialize Your Project

Start by creating your Node.js application:

mkdir node-ci-cd-app && cd node-ci-cd-app
npm init -y

2. Install Necessary Dependencies

Use the following commands to install Express and testing libraries:

npm install express
npm install --save-dev jest supertest

3. Create Essential Files

app.js

This is your main server file:

const express = require('express');
const pingRoute = require('./routes/ping');

const app = express();

app.use('/ping', pingRoute);

const PORT = process.env.PORT || 3000;
if (require.main === module) {
  app.listen(PORT, () => console.log(`Server running on port ${PORT}`));
}

module.exports = app;

routes/ping.js

Set up a basic route:

const express = require('express');
const router = express.Router();

router.get('/', (req, res) => {
  res.send('pong');
});

module.exports = router;

tests/ping.test.js

Write a test for your route:

const request = require('supertest');
const app = require('../app');

describe('GET /ping', () => {
  it('should return pong', async () => {
    const res = await request(app).get('/ping');
    expect(res.statusCode).toBe(200);
    expect(res.text).toBe('pong');
  });
});

.gitignore

Create a .gitignore file to exclude unnecessary files:

node_modules
.env

Update package.json

Modify the scripts section in your package.json:

"scripts": {
  "start": "node app.js",
  "test": "jest"
}

You can now run your application:

node app.js         # Start the server
npm test            # Run tests

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🚀 Step 2: Push to GitLab & Set Up CI/CD Pipeline

1. Create a New GitLab Repository

• Go to GitLab

• Click "New Project" > "Create blank project"

• Name your project node-ci-cd-app

• Click "Create Project"

2. Connect Your Local Repository

Run these commands in your terminal:

git init
git remote add origin https://gitlab.com/your-username/node-ci-cd-app.git
git config --global user.name "Your Name"
git config --global user.email "you@example.com"
git add .
git commit -m "Initial commit"
git branch -M main
git push -u origin main

⚠️ If you see the error: error: src refspec main does not match any, run:

git branch -M main

Then push again:

git push -u origin main

3. Create .gitlab-ci.yml

Add a CI configuration file in your root directory:

stages:
  - test

run_tests:
  stage: test
  image: node:18
  script:
    - npm install
    - npm test

4. Push to Trigger the Pipeline

Add the CI/CD configuration file:

git add .gitlab-ci.yml
git commit -m "Add CI pipeline for testing"
git push

5. Monitor Your Pipeline on GitLab

• Navigate to CI/CD > Pipelines in your GitLab project.

• Check the status and logs to ensure everything is functioning properly.

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📊 Step 3: Next Steps — Deploy to Render

In the next part, we will:

• Deploy your Node.js app to Render using Deploy Hooks.

• Secure secrets with GitLab CI/CD Variables.

• Add a deploy stage to your pipeline.

Stay tuned for the next installment!

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This guide provides a comprehensive approach to setting up a CI/CD pipeline for your Node.js application. If you have questions or need further assistance, feel free to reach out in the comments!

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