Deploy & Secure FastAPI with Docker on DigitalOcean (Step-by-Step)

#fastapi #docker #digitalocean #deploy

FastAPI is an insanely fast Python framework for building APIs — but getting it to production securely is where many developers struggle.
In this guide, we’ll containerize a FastAPI app, run it behind Nginx, enable HTTPS with Let’s Encrypt, and deploy it to a DigitalOcean Droplet — production-ready from day one.

By the end, you’ll have:

Portable deployment with Docker
Secure communication (HTTPS + Nginx reverse proxy)
Easy scaling for high-traffic apps

High-Level Steps

Create & SSH into a DigitalOcean Droplet
Install Docker & Docker Compose
Write a minimal FastAPI app (main.py)
Create Dockerfile for containerization
Add Nginx reverse proxy via docker-compose.yml
Configure DNS & domain
Install Certbot & enable HTTPS
Run with Gunicorn for production

Minimal Dockerfile

FROM python:3.11-slim
WORKDIR /app
COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt
COPY . .
EXPOSE 8000
CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]

docker-compose.yml with Nginx

version: "3.8"
services:
  app:
    build: .
    container_name: fastapi_app
    restart: unless-stopped
    expose:
      - "8000"

  nginx:
    image: nginx:alpine
    container_name: nginx_proxy
    depends_on:
      - app
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - ./nginx.conf:/etc/nginx/conf.d/default.conf:ro
      - certbot-etc:/etc/letsencrypt
      - certbot-var:/var/www/certbot
    restart: unless-stopped

volumes:
  certbot-etc:
  certbot-var: