Deploying FastAPI with Docker: A Production Guide

FastAPI is one of the fastest Python web frameworks available. When it comes to deploying it in production, Docker is the go-to choice for consistency, scalability, and ease of management.

Prerequisites

• Python 3.11+
• Docker & Docker Compose
• A VPS (DigitalOcean, AWS, etc.)

Step 1: Create the FastAPI App

from fastapi import FastAPI

app = FastAPI()

@app.get("/health")
async def health():
    return {"status": "ok"}

Step 2: Write the 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", "--workers", "4"]

Step 3: Docker Compose

version: "3.9"
services:
  api:
    build: .
    restart: always
    environment:
      - DATABASE_URL=postgresql://user:pass@db:5432/mydb
    depends_on:
      - db
  db:
    image: postgres:15
    volumes:
      - postgres_data:/var/lib/postgresql/data

volumes:
  postgres_data:

Step 4: Nginx Reverse Proxy

server {
    listen 80;
    server_name yourdomain.com;

    location / {
        proxy_pass http://api:8000;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

Conclusion

With this setup, you get a production-ready FastAPI deployment with automatic restarts, reverse proxy, and database persistence.