🚀 Day 36: Automating Docker Builds with GitHub Actions

Welcome to Day 36 of your DevOps journey! Today, we’ll automate building a Docker image and pushing it to Docker Hub using GitHub Actions. Let’s dive in and make it happen! 🎉

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🔧 Prerequisites

Before we start, ensure the following are ready:

• ✅ Docker Hub Account: You’re all set with ritesh355.

• ✅ GitHub Secrets:

  • DOCKER_USERNAME: ritesh355

  • DOCKER_PASSWORD: Your Docker Hub access token (not your password).

Not set up? No worries! Create a Docker Hub account at docker.com and add the secrets in your GitHub repo under Settings > Secrets and variables > Actions. Let me know if you need help!

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📁 Step-by-Step Project Setup

We’ll create a simple Node.js app, containerize it with Docker, and automate its deployment to Docker Hub using GitHub Actions.

1. 🔨 Create a New GitHub Repo

Let’s set up the project directory and initialize a Node.js app:

mkdir node-docker-push
cd node-docker-push
npm init -y

2. 📦 Create a Sample Node.js App

Create a file named app.js with the following content:

const http = require('http');

const server = http.createServer((req, res) => {
  res.end('Hello from Docker + GitHub Actions 🚀');
});

server.listen(3000, () => {
  console.log('Server running on http://localhost:3000');
});

3. 📄 Create a Dockerfile

Create a Dockerfile to containerize the app:

FROM node:18-alpine

WORKDIR /app

COPY . .

EXPOSE 3000

CMD ["node", "app.js"]

4. 📝 Set Up GitHub Actions Workflow

Create a workflow file at .github/workflows/docker-publish.yml:

name: 🚀 Build and Push Docker Image

on:
  push:
    branches: [ main ]

jobs:
  build-and-push:
    runs-on: ubuntu-latest

    steps:
      - name: 🧾 Checkout code
        uses: actions/checkout@v3

      - name: 🔐 Log in to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}

      - name: 🛠️ Build and push Docker image
        uses: docker/build-push-action@v5
        with:
          context: .
          push: true
          tags: ritesh355/node-docker-push:latest

This workflow triggers on every push to the main branch, checks out the code, logs into Docker Hub, and builds/pushes the Docker image.

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🚀 Run the Workflow

Follow these steps to push your project and trigger the workflow:

1. Initialize Git and Push to GitHub:

git init
git remote add origin https://github.com/ritesh355/node-docker-push.git
git add .
git commit -m "Day 34 - Push Docker Image to Docker Hub"
git branch -M main
git push -u origin main

2. Monitor the Workflow:

   • Go to your GitHub repo → Actions tab.

   • Watch the workflow run in real-time! 🎉

3. Check Docker Hub:

   • Once the workflow completes, visit Docker Hub and find your image: ritesh355/node-docker-push:latest. ✅

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✅ Verify the Image Locally

If you have Docker installed, test the image locally:

docker pull ritesh355/node-docker-push:latest
docker run -p 3000:3000 ritesh355/node-docker-push

Open your browser and visit: http://localhost:3000. You should see:

"Hello from Docker + GitHub Actions 🚀"

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🎉 Congratulations!

You’ve successfully automated building and pushing a Docker image to Docker Hub using GitHub Actions! Keep rocking your DevOps journey! 💪

Need help? Drop a comment or question, and I’ll guide you through any issues!