Building a CI/CD Pipeline with GitHub Actions

Introduction

Continuous Integration and Continuous Deployment (CI/CD) are essential practices in modern software development. They help automate the process of testing, building, and deploying code, ensuring that your application is always in a deployable state. In this tutorial, we’ll set up a CI/CD pipeline using GitHub Actions for a simple Node.js application.

Prerequisites

To follow along, you should have a basic understanding of:

Git and GitHub
YAML syntax
Basic CI/CD concepts

Setting Up the Project

1. Create a New Repository

Create a new repository on GitHub for your project. You can use an existing repository if you prefer.

2. Clone the Repository

Clone the repository to your local machine:

git clone https://github.com/your-username/your-repository.git
cd your-repository

3. Add a Simple Node.js Application

For demonstration purposes, we’ll use a simple Node.js application. Create a file named index.js with the following content:

// filepath: ci-cd-github-actions/index.js
const express = require("express");
const app = express();

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

app.listen(3000, () => {
  console.log("Server is running on port 3000");
});

4. Add a Test Script

Create a file named test.js with a simple test script:

// filepath: ci-cd-github-actions/test.js
const request = require("supertest");
const express = require("express");

const app = express();
app.get("/", (req, res) => {
  res.send("Hello, World!");
});

describe("GET /", () => {
  it("should return Hello, World!", done => {
    request(app).get("/").expect("Hello, World!", done);
  });
});

5. Add Dependencies

Create a package.json file and add the necessary dependencies:

// filepath: ci-cd-github-actions/package.json
{
  "name": "ci-cd-github-actions",
  "version": "1.0.0",
  "main": "index.js",
  "scripts": {
    "start": "node index.js",
    "test": "mocha test.js"
  },
  "dependencies": {
    "express": "^4.17.1"
  },
  "devDependencies": {
    "mocha": "^8.3.2",
    "supertest": "^6.1.3"
  }
}

6. Create a GitHub Actions Workflow

Create a directory named .github/workflows and add a file named ci.yml with the following content:

// filepath: ci-cd-github-actions/.github/workflows/ci.yml
name: CI

on:
  push:
    branches:
      - main
  pull_request:
    branches:
      - main

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout code
        uses: actions/checkout@v2

      - name: Set up Node.js
        uses: actions/setup-node@v2
        with:
          node-version: "14"

      - name: Install dependencies
        run: npm install

      - name: Run tests
        run: npm test

Testing the CI/CD Pipeline

1. Push Changes to GitHub

Commit your changes and push them to GitHub:

git add .
git commit -m "Set up CI/CD pipeline with GitHub Actions"
git push origin main

2. Check GitHub Actions

Navigate to the “Actions” tab in your GitHub repository to see the CI/CD pipeline in action. You should see the workflow running and the tests passing.

Conclusion

We just set up a CI/CD pipeline using GitHub Actions. This pipeline automatically tests and builds your code whenever you push changes to the main branch or create a pull request. GitHub Actions provides a powerful and flexible way to automate your development workflow, ensuring that your application is always in a deployable state.

Additional Resources

For more information on GitHub Actions and CI/CD practices, check out the following resources: