How to Deploy a MERN Stack Application with AWS, Docker, and GitHub Actions

Deploying a MERN stack (MongoDB, Express, React, Node.js) application to AWS can be a smooth and scalable process when combined with Docker for consistent environments and GitHub Actions for automated deployments. This guide will walk you through each step of the process using AWS services, Docker, and CI/CD with GitHub Actions.

Step 1: Prepare Your MERN Application

Before deploying, ensure your MERN application is ready for production.

• • • Frontend (React): Run npm run build to generate a production-ready build of your React app. This creates static files (HTML, CSS, JS) inside the build/ directory.
    • Backend (Node.js/Express): Make sure your Node.js backend is production-ready by configuring environment variables for sensitive data (e.g., MongoDB URI, secret keys, etc.).

Step 2: Dockerize Your Application

Docker ensures that your application runs consistently across all environments. Here’s how to dockerize your MERN stack app:

• • • Docker for Frontend: Create a Dockerfile for your React app that builds the production bundle and serves it via a lightweight web server like Nginx.
    • Docker for Backend: Similarly, create a Dockerfile for your Node.js backend that installs dependencies and runs your Express server.

Dockerizing both the frontend and backend helps you manage dependencies and ensures that the application will work consistently across different platforms, whether on your local machine or in the cloud.

Step 3: Set Up MongoDB with AWS

Instead of managing your own MongoDB instance on EC2, we recommend using MongoDB Atlas for a hassle-free, managed database solution:

• • • MongoDB Atlas: Create an Atlas cluster, configure your database, and get the MongoDB URI for connecting to it.
    • Environment Variables: Store the MongoDB URI and any other sensitive information (like API keys) in environment variables to keep them secure.

Step 4: Set Up AWS Services

Now that your app is ready, let’s set up the necessary AWS services for deployment:

• • • EC2 or ECS for Backend:

      • EC2: Launch an EC2 instance to host your Dockerized backend. Install Docker, push your backend image to the instance, and run it using Docker.
      • ECS (Elastic Container Service): For more scalable deployments, use ECS with Fargate (serverless) or EC2 instances to run your Docker containers.

    • S3 + CloudFront for Frontend:

      • S3: Store the static files of your React app in an S3 bucket for hosting.
      • CloudFront: Use CloudFront, AWS's CDN, to serve these files globally, ensuring fast and reliable access for your users.

Step 5: Set Up GitHub Actions for Continuous Integration and Continuous Deployment (CI/CD)

Automate the build and deployment process with GitHub Actions. Here’s how to integrate Docker and CI/CD into your workflow:

• • • GitHub Actions Workflow: Create workflows that automatically build and deploy your application whenever changes are pushed to your GitHub repository.
      • Build Docker Images: The workflow will first build the Docker images for both the frontend and backend.
      • Push to ECR (Elastic Container Registry): Push the Docker images to Amazon ECR (or Docker Hub) for easy deployment.
      • Deploy Backend to EC2/ECS: Automatically deploy the backend Docker container to EC2 or ECS using SSH commands or ECS deployment scripts.
      • Deploy Frontend to S3: Sync the built React app with your S3 bucket and invalidate the CloudFront cache to ensure users get the latest version.

With GitHub Actions, you can ensure that every change to your codebase is automatically tested, built, and deployed, eliminating manual steps and reducing the risk of errors.

Step 6: Set Up a Custom Domain and SSL (Optional but Recommended)

To make your app more professional and secure, configure a custom domain and SSL certificate:

• • • Amazon Route 53: Use Route 53 to manage your domain. Point your domain to CloudFront for the frontend and EC2/ECS for the backend API.
    • AWS Certificate Manager (ACM): Request an SSL certificate for your domain through ACM and apply it to your CloudFront distribution to enable HTTPS.

This ensures that your users access your application securely via https://www.yoursite.com.

Step 7: Monitor and Scale Your Application

Once your application is deployed, it's important to monitor its performance and ensure it can scale with traffic:

• • • Amazon CloudWatch: Use CloudWatch to monitor logs and performance metrics for both your frontend (S3/CloudFront) and backend (EC2/ECS). Set up alarms to notify you of any issues.
    • Auto Scaling: Leverage EC2 Auto Scaling or ECS Auto Scaling to automatically adjust resources based on user demand. This ensures that your application performs well under varying levels of traffic.

By leveraging these tools and services, you can build a robust, automated, and scalable deployment pipeline for your MERN stack application on AWS.