FastAPI Backend Template

A production-ready FastAPI backend template with Docker, MySQL, Redis, MinIO (S3-compatible storage), and authentication built-in. This template provides a solid foundation for building scalable web applications with modern Python technologies.

Table of Contents

• Features
• Architecture Overview
• Prerequisites
• Quick Start
• Project Structure
• Configuration
• Services
• Authentication & Authorization
• Database Management
• API Documentation
• Development Guide
• Production Deployment
• Troubleshooting

Features

• FastAPI - Modern, fast web framework for building APIs
• Docker & Docker Compose - Containerized development and deployment
• MySQL 8.3 - Relational database with Adminer GUI
• Redis 7.0 - In-memory data store for caching and sessions
• MinIO - S3-compatible object storage for file uploads
• Alembic - Database migration tool
• JWT Authentication - OAuth2 with Bearer tokens
• Multi-level Authorization - User, Admin, and Super Admin roles
• Auto-generated API Documentation - Swagger UI, ReDoc, and Stoplight Elements
• CORS Support - Cross-Origin Resource Sharing enabled
• Environment-based Configuration - Easy configuration management
• Hot Reload - Development server with automatic code reloading

Architecture Overview

The template uses a microservices architecture with the following components:

┌─────────────────┐     ┌─────────────────┐     ┌─────────────────┐
│                 │     │                 │     │                 │
│   FastAPI App   │─── ▶│     MySQL       │     │     Redis       │
│   (Port 8000)   │     │   (Port 3306)   │     │   (Port 6379)   │
│                 │     │                 │     │                 │
└────────┬────────┘     └─────────────────┘     └─────────────────┘
         │              ┌─────────────────┐     ┌─────────────────┐
         │              │                 │     │                 │
         └─────────────▶│     MinIO       │     │    Adminer      │
                        │  (Ports 9000/1) │     │   (Port 8001)   │
                        │                 │     │                 │
                        └─────────────────┘     └─────────────────┘

Prerequisites

• Docker Engine 20.10+
• Docker Compose 2.0+
• Git
• Python 3.11+ (for local development)

Quick Start

1. Clone the repository

   git clone <repository-url>
   cd FastAPI-template

2. Set up environment variables

   cp example.env .env
   # Edit .env file with your configurations if needed

3. Start all services

   docker-compose up -d

4. Initialize the database

   • Visit http://localhost:8000/db/renewDB to create database tables
   • This endpoint requires Super Admin authentication (X-SUPER-ADMIN-TOKEN: admin.root)

5. Access the services

   • FastAPI Application: http://localhost:8000
   • API Documentation: http://localhost:8000/docs
   • Database Admin (Adminer): http://localhost:8001
   • MinIO Console: http://localhost:9001 (admin/admin1234)

Project Structure

FastAPI-template/
├── alembic/                  # Database migration files
│   ├── versions/            # Migration version files
│   ├── env.py              # Alembic environment config
│   └── script.py.mako      # Migration template
├── src/                     # Application source code
│   ├── crud/               # Database CRUD operations
│   │   └── user.py         # User-related CRUD operations
│   ├── database/           # Database configuration
│   │   ├── database.py     # Database connection setup
│   │   ├── models.py       # SQLAlchemy models
│   │   └── utils.py        # Database utilities
│   ├── dependencies/       # FastAPI dependencies
│   │   ├── auth.py         # Authentication dependencies
│   │   └── basic.py        # Basic dependencies
│   ├── routers/           # API route handlers
│   │   ├── db/            # Database management routes
│   │   ├── private/       # Authenticated user routes
│   │   ├── public/        # Public routes
│   │   └── root/          # Admin routes
│   ├── schemas/           # Pydantic models
│   │   ├── base.py        # Base schema classes
│   │   └── basic.py       # Basic schema models
│   ├── utils/             # Utility functions
│   │   ├── credentials.py  # Password & JWT handling
│   │   ├── handler.py      # Error handlers
│   │   ├── s3.py          # S3/MinIO integration
│   │   └── swagger.py      # Custom Swagger UI
│   └── server.py          # Main FastAPI application
├── volume/                # Docker volumes (gitignored)
├── docker-compose.yaml    # Docker services configuration
├── Dockerfile            # Backend container definition
├── requirements.txt      # Python dependencies
├── alembic.ini          # Alembic configuration
├── example.env          # Environment variables template
├── init-minio.sh        # MinIO initialization script
└── minio-entrypoint.sh  # MinIO startup script

Configuration

Environment Variables

Copy example.env to .env and configure:

# Database Configuration
DB_HOST=mysql              # MySQL container hostname
DB_USER=admin              # Database user
DB_PASS=admin1234          # Database password
DB_PORT=3306              # MySQL port
DB_NAME=template_db        # Database name

# AWS S3 Configuration (for production)
AWS_ACCESS_KEY_ID=         # AWS access key
AWS_SECRET_ACCESS_KEY=     # AWS secret key
AWS_REGION=                # AWS region
AWS_S3_BUCKET=template-bucket
AWS_CLOUDFRONT_DOMAIN=     # CloudFront distribution domain

# MinIO Configuration (for development)
S3_ENDPOINT_URL=http://minio:9000
S3_PROVIDER=minio          # Use 'aws' for production
MINIO_ROOT_USER=admin
MINIO_ROOT_PASSWORD=admin1234
MINIO_DNS_URL=http://localhost:9000

# API Keys
ADMIN_API_KEY=admin        # Admin API key
SUPER_ADMIN_API_KEY=admin.root  # Super Admin API key

Services

Backend (FastAPI)

The main application service running on port 8000:

• Framework: FastAPI with Uvicorn ASGI server
• Features: Auto-reload, CORS enabled, JWT authentication
• Endpoints: Public, Private (authenticated), Admin, and Database management

MySQL Database

Relational database for persistent data storage:

• Version: MySQL 8.3
• Default Database: template_db
• Root Password: root
• User Credentials: admin/admin1234
• Data Persistence: ./volume/mysql_data

Redis Cache

In-memory data store for caching and sessions:

• Version: Redis 7.0 Alpine
• Port: 6379 (internal only)
• Data Persistence: ./volume/redis_data

MinIO Object Storage

S3-compatible object storage for file uploads:

• API Port: 9000
• Console Port: 9001
• Default Bucket: template-bucket (public read access)
• Credentials: admin/admin1234
• Data Persistence: ./volume/minio_data

Adminer

Web-based database management tool:

• Port: 8001
• Supported Databases: MySQL, PostgreSQL, SQLite, MS SQL
• Login with: Server: mysql, Username: admin, Password: admin1234

Authentication & Authorization

Authentication Flow

1. Login: POST to /public/auth/login with username/password
2. Token: Receive JWT token in response
3. Authorization: Include token in Authorization header: Bearer <token>

Authorization Levels

1. Public Routes (/public/*)

   • No authentication required
   • Login endpoint available here

2. Private Routes (/private/*)

   • Requires valid JWT token
   • For authenticated users

3. Admin Routes (/root/*)

   • Requires X-ADMIN-TOKEN header
   • Default: admin

4. Super Admin Routes (/db/*)

   • Requires X-SUPER-ADMIN-TOKEN header
   • Default: admin.root
   • Database management operations

Test Credentials

Default test user (created via /db/renewDB):

Username: test-username
Password: test-password

Database Management

Models

The template includes three main models:

1. User - Basic user information

   • id (UUID)
   • name (unique, 16 chars)
   • created_at, updated_at timestamps

2. UserAccount - Authentication credentials

   • username (unique, 16 chars)
   • password (hashed)
   • Linked to User model

3. Blob - File metadata storage

   • content_type
   • filename
   • url (S3/MinIO URL)
   • Many-to-many relationship with Users

Database Operations

Initialize/Reset Database:

curl -X POST http://localhost:8000/db/renew \
  -H "X-SUPER-ADMIN-TOKEN: admin.root"

Run Alembic Migrations (API):

# Full migration (delete old versions, create revision, and upgrade)
curl -X POST http://localhost:8000/db/alembic \
  -H "X-SUPER-ADMIN-TOKEN: admin.root"

# Skip revision generation (only upgrade existing migrations)
curl -X POST "http://localhost:8000/db/alembic?skip_revision=true" \
  -H "X-SUPER-ADMIN-TOKEN: admin.root"

# Keep existing version files
curl -X POST "http://localhost:8000/db/alembic?delete_first=false" \
  -H "X-SUPER-ADMIN-TOKEN: admin.root"

Migrations with Alembic (Manual)

Create a new migration:

docker exec template-backend alembic revision --autogenerate -m "Description"

Apply migrations:

docker exec template-backend alembic upgrade head

Rollback migration:

docker exec template-backend alembic downgrade -1

API Documentation

The template provides three different API documentation interfaces:

1. Swagger UI (Interactive)

   • URL: http://localhost:8000/docs
   • Features: Try out endpoints, authentication support
   • Custom dark theme included

2. ReDoc (Clean Documentation)

   • URL: http://localhost:8000/redoc
   • Features: Clean, readable API documentation

3. Stoplight Elements (Modern UI)

   • URL: http://localhost:8000/elements
   • Features: Modern design, code samples

Development Guide

Local Development Setup

1. Install Python dependencies locally:

   python -m venv venv
   source venv/bin/activate  # On Windows: venv\Scripts\activate
   pip install -r requirements.txt

2. IDE Configuration:

   • Set Python interpreter to venv
   • Configure PYTHONPATH to include project root
   • Enable type checking for better code completion

3. Hot Reload:

   • The Docker container runs with --reload flag
   • Changes to Python files automatically restart the server

Adding New Features

1. Create a new model:

# src/database/models.py
class NewModel(Base):
    __tablename__ = "new_models"
    
    id = Column(String(36), primary_key=True)
    name = Column(String(255))
    # Add more fields

2. Create CRUD operations:

# src/crud/new_model.py
from sqlalchemy.orm import Session
from src.database import models

def create_item(db: Session, name: str):
    item = models.NewModel(id=str(ulid.new()), name=name)
    db.add(item)
    db.commit()
    return item

3. Create schemas:

# src/schemas/new_model.py
from pydantic import BaseModel

class NewModelCreate(BaseModel):
    name: str

class NewModelResponse(BaseModel):
    id: str
    name: str
    
    class Config:
        from_attributes = True

4. Create router:

# src/routers/private/new_model.py
from fastapi import APIRouter, Depends
from sqlalchemy.orm import Session
from src.dependencies.basic import get_db
from src.crud import new_model as crud
from src.schemas import new_model as schemas

router = APIRouter()

@router.post("/", response_model=schemas.NewModelResponse)
def create_item(
    item: schemas.NewModelCreate,
    db: Session = Depends(get_db)
):
    return crud.create_item(db, item.name)

Working with S3/MinIO

Upload a file:

from src.utils.s3 import s3_client
import ulid

# Upload file
file_key = f"uploads/{ulid.new()}/filename.jpg"
s3_client.upload_file("local_file.jpg", "template-bucket", file_key)

# Get public URL
url = f"http://localhost:9000/template-bucket/{file_key}"

Production Deployment

Environment Configuration

1. Update .env for production:

   S3_PROVIDER=aws
   AWS_ACCESS_KEY_ID=your-key
   AWS_SECRET_ACCESS_KEY=your-secret
   AWS_REGION=us-east-1
   ADMIN_API_KEY=strong-random-key
   SUPER_ADMIN_API_KEY=very-strong-random-key

2. Update docker-compose.yaml:

   • Remove development volumes
   • Change command to use gunicorn instead of --reload
   • Add health checks

3. Security considerations:

   • Use strong, unique passwords
   • Enable HTTPS with SSL certificates
   • Implement rate limiting
   • Add request validation
   • Use environment-specific configurations

Deployment Options

1. Docker Swarm:

docker stack deploy -c docker-compose.yaml app-stack

2. Kubernetes:

• Convert docker-compose to K8s manifests
• Use ConfigMaps for environment variables
• Set up Ingress for load balancing

3. Cloud Platforms:

• AWS ECS/Fargate
• Google Cloud Run
• Azure Container Instances

Database Backups

Manual backup:

docker exec template-mysql mysqldump -u admin -padmin1234 template_db > backup.sql

Restore backup:

docker exec -i template-mysql mysql -u admin -padmin1234 template_db < backup.sql

Troubleshooting

Common Issues

1. Container fails to start:

• Check logs: docker-compose logs backend
• Ensure all ports are available
• Verify environment variables

2. Database connection errors:

• Wait for MySQL to fully initialize
• Check credentials in .env
• Ensure mysql container is running

3. MinIO bucket not accessible:

• Check if initialization script ran
• Verify MinIO credentials
• Ensure bucket policy is applied

4. Authentication failures:

• Verify JWT token is included in headers
• Check token expiration
• Ensure API keys match .env values

Debug Commands

# View all logs
docker-compose logs -f

# Check container status
docker-compose ps

# Enter container shell
docker exec -it template-backend bash

# Test database connection
docker exec template-mysql mysql -u admin -padmin1234 -e "SHOW DATABASES;"

# Check Redis connection
docker exec template-redis redis-cli ping

Reset Everything

# Stop and remove all containers
docker-compose down

# Remove volumes (WARNING: Deletes all data)
docker-compose down -v

# Clean rebuild
docker-compose build --no-cache
docker-compose up -d

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests for new features
5. Submit a pull request

License

This project is licensed under the MIT License - see the LICENSE file for details.