User Registration API

This repository provides an API for user registration and email verification using FastAPI.

Features

• Register a user with email and password
• Send a 4-digit verification code via email
• Activate a user account using HTTP Basic Auth with the received code
• The verification code is valid for 1 minute only

Architecture

Docker Services

This project is structured into the following Docker services:

• FastAPI: Handles HTTP requests and business logic
• PostgreSQL: Stores user and verification data
• MailDev: Simulates an SMTP email server
• RabbitMQ: Message broker for background tasks
• Celery Worker: Processes asynchronous tasks

architecture-beta
    service localhost(server)[Host]

    group docker_compose[Docker Compose]
    service api(server)[FastAPI] in docker_compose
    service db(database)[PostgreSQL] in docker_compose
    service email(server)[MailDev] in docker_compose
    service broker(queue)[RabbitMQ] in docker_compose
    service worker(worker)[Celery Worker] in docker_compose
    junction junction_host_email

    localhost:R <--> L:api

    api:B <--> T:db

    api:R --> L:broker
    broker:T --> B:worker
    worker:L --> R:email

    email:L -- R:junction_host_email
    junction_host_email:B --> T:localhost
    localhost:T <-- B:junction_host_email    

Loading

Codebase Structure

The application follows a modular layout inside src/:

• main.py: FastAPI app entry point
• auth/: Authentication-related utilities and dependencies
• user/: User logic including schemas, service, tasks, and routes
• workers/: Celery configuration
• Shared modules: config.py, database.py, exceptions.py, logging.py

graph TD;
    subgraph src/
        main[main.py] --> app[FastAPI app]

        app --> auth
        auth --> utils_auth[utils.py]
        auth --> deps_auth[dependencies.py]

        app --> user
        user --> router_user[router.py]
        user --> service_user[service.py]
        user --> crud_user[crud.py]
        user --> schemas_user[schemas.py]
        user --> tasks_user[tasks/email.py]

        app --> workers
        workers --> celery[celery.py]

        app --> shared_config[config.py]
        app --> shared_db[database.py]
        app --> shared_exceptions[exceptions.py]
        app --> shared_logging[logging.py]
    end

Loading

Setup

Prerequisites

Make sure you have the following installed:

• Docker
• Docker Compose

Environment File

You can use the default .env.example file in the following steps or create your custom environment file:

cp .env.example <your-env-file>

You can modify the file according to your needs, and create a file for each environment (for example: development and production)

⚠️ Important: Docker Compose loads the environment file automatically if it's named .env.
If your environment file has a different name, you must include it explicitly in each command, for example:

docker compose --env-file <your-env-file> up --build

Usage

Start in Development Mode (with override)

Use the default docker-compose.override.yml to enable volume mounting and code reload:

docker compose --env-file <your-env-file> up --build

In this mode, the override compose file allows the server to watch your code and restarts automatically on changes.

Start in Production Mode (without override)

This only uses docker-compose.yml, ignoring the override file:

docker compose --env-file <your-env-file> -f docker-compose.yml up --build

Accessing the Services

• API Docs: http://localhost:<EXPOSED_API_PORT>/docs
• MailDev UI: http://localhost:<EXPOSED_SMTP_WEB_PORT>

Running Tests

docker compose exec api pytest

Cleanup

Stop all services

docker compose down

Remove all volumes (irreversible)

docker compose down -v

Possible Improvements

• Add docstrings to models, endpoints, and services for better documentation.
• Improve security (e.g., timing attack protection, request throttling).

License

MIT