CI/CD for Deploying Docker Application on EC2 with GitHub Actions

[Tenkus_La]

This guide explains how to set up a CI/CD pipeline to automatically deploy a Dockerized FastAPI app (or any containerized app) to an EC2 instance using GitHub Actions.

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Prerequisites

• A running EC2 Ubuntu instance
• Your app is containerized with Docker Compose
• SSH access to EC2 (user: ubuntu or similar)
• Your app code is hosted on GitHub
• Optional: DNS domain and SSL setup via Nginx + Let’s Encrypt

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Step 1: Generate an SSH Deploy Key

Create a new SSH key pair (locally or in CI):

ssh-keygen -t ed25519 -C "github-deploy-key"

Step 2: Add Public Key to EC2

1. SSH into EC2:

  ssh ubuntu@<your-ec2-ip>

2. Open the authorized_keys file:

nano ~/.ssh/authorized_keys

3. Paste in the contents of id_ed25519.pub.
4. Set proper permissions:

chmod 700 ~/.ssh
chmod 600 ~/.ssh/authorized_keys

You can have multiple lines in authorized_keys.

Step 3: Allow Docker Without sudo

On EC2:

sudo usermod -aG docker ubuntu

Then log out and log back in (or reboot):

exit

Reconnect and test:

docker ps

Step 4: Add GitHub Secrets

Go to your GitHub repo → Settings → Secrets and variables → Actions, and add:

Name	Description
EC2_HOST	EC2 IP or DNS
EC2_USER	SSH username (e.g., ubuntu)
EC2_SSH_KEY	Content of your private key id_ed25519

Step 5: Create GitHub Actions Workflow

Create a file at .github/workflows/deploy.yml:

name: Deploy to EC2

on:
  push:
    branches: [main]  # Update if using another branch

jobs:
  deploy:
    runs-on: ubuntu-latest

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

      - name: SSH & Deploy
        uses: appleboy/ssh-action@v1.0.3
        with:
          host: ${{ secrets.EC2_HOST }}
          username: ${{ secrets.EC2_USER }}
          key: ${{ secrets.EC2_SSH_KEY }}
          script: |
            cd /home/ubuntu/translation-worker-api
            git pull origin main
            docker-compose down
            docker-compose up -d --build

Step 6: Push to GitHub to Deploy

git add .
git commit -m "Deploying via GitHub Actions"
git push origin main

Check GitHub → Actions tab to see the workflow progress.

Example Directory Structure

translation-worker-api/
├── .github/
│ └── workflows/
│ └── deploy.yml
├── docker-compose.yml
├── app/
│ └── main.py
└── …

Optional Enhancements

• Add .env file support for Docker Compose
• Configure Nginx + Certbot for subdomains and SSL
• Use GitHub environments (staging, production)
• Add deploy notifications (e.g., Slack, Discord)
• Write a deploy.sh script with error handling