In today’s fast-paced development world, automation is key.
Whether you're working solo or in a team, a strong CI/CD setup ensures reliability, efficiency, and peace of mind.
In this blog, I’ll walk you through how I implemented CI/CD in my own project using GitHub Actions and Docker—from pull request checks to Docker Hub deployments.

🚀 What is CI/CD and Why It Matters

In software projects, CI/CD (Continuous Integration and Continuous Deployment) plays a crucial role in maintaining the quality and reliability of the codebase. Whether it’s an open-source or private project, a robust CI/CD pipeline helps manage code changes, streamline development, and boost collaboration.

🔑 Key Benefits

1. Code Integration
   CI/CD pipelines automatically integrate code on every push, reducing conflicts and keeping branches aligned.

2. Automated Testing
   Unit, integration, and E2E tests run automatically, helping you catch bugs early.

3. Workflows
   Tools like GitHub Actions let you define automated workflows for builds, tests, deployments, and more.

4. Code Quality Checks
   Linting, static analysis, and security scans help ensure high standards.

5. Deployment Automation
   CD pipelines handle deployments reliably and consistently across environments.

⚙️ Setting Up CI with GitHub Actions

Let’s start by setting up a simple CI pipeline that ensures code builds successfully when a pull request is created.

📁 File Structure

Create a file at:

.github/workflows/build.yml

### 🛠️ CI Workflow Code

```yaml
name: Build on PR

on:
  pull_request:
    branches:
      - main

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Use Node.js
        uses: actions/setup-node@v3
        with:
          node-version: '20'
      - name: Install Dependencies
        run: npm install
      - name: Run Build
        run: npm run build

✅ What It Does

• Triggers on PRs to the main branch.
• Uses an Ubuntu runner.
• Checks out code, sets up Node.js v20.
• Installs dependencies and runs the build command.

This ensures all PRs are validated for successful builds before merging.

🐳 Dockerizing the App for CD

Before we can deploy, let’s containerize our app. Assume we’re deploying the user-app from a monorepo.

📄 Dockerfile (docker/Dockerfile.user)

FROM node:20.12.0-alpine3.19
 
WORKDIR /usr/src/app
 
COPY package.json package-lock.json turbo.json tsconfig.json ./
COPY apps ./apps
COPY packages ./packages
 
RUN npm install
RUN npm run generate-prisma
RUN npm run build --filter=user-app
 
CMD ["npm", "run", "start-user-app"]

🔍 Breakdown

• Uses a lightweight Node.js Alpine image.
• Sets up the working directory and copies configs and code.
• Installs dependencies, generates Prisma client, builds the specific app.
• Starts the user app.

🚚 Continuous Deployment to Docker Hub

Now, let’s automate the deployment of this Docker image using GitHub Actions.

🧪 Prerequisites

1. Create Docker Hub account

2. Make a new repo on Docker Hub

3. Add GitHub secrets:

   • DOCKER_USERNAME
   • DOCKER_PASSWORD (use access token)

📁 File Structure

Create:

.github/workflows/deploy.yml

🧩 Deployment Workflow Code

name: Build and Deploy to Docker Hub
 
on:
  push:
    branches:
      - main
 
jobs:
  build-and-push:
    runs-on: ubuntu-latest
    steps:
      - name: Check Out Repo
        uses: actions/checkout@v2
 
      - name: Log in to Docker Hub
        uses: docker/login-action@v2
        with:
          username: ${{ secrets.DOCKER_USERNAME }}
          password: ${{ secrets.DOCKER_PASSWORD }}
 
      - name: Build and Push Docker image
        uses: docker/build-push-action@v4
        with:
          context: .
          file: ./docker/Dockerfile.user
          push: true
          tags: your-dockerhub-username/your-repo-name:latest
 
      - name: Verify Pushed Image
        run: docker pull your-dockerhub-username/your-repo-name:latest

📌 Replace

Replace:

• your-dockerhub-username
• your-repo-name

with your actual Docker Hub credentials.

🧠 Summary

We’ve covered:

• Setting up a CI workflow to validate PR builds.
• Dockerizing a monorepo-based app.
• Automating Docker image builds and pushing to Docker Hub.

CI/CD pipelines like this one keep your development process efficient, collaborative, and production-ready.

📂 Source Code

You can explore the full implementation in my repository here: 👉 GitHub Repo