Python Web Course Assignment: Docker Basics with FastAPI

Assignment Overview

This project is an academic assignment from the Python Web course. The goal is to containerize a simple FastAPI application and connect it to PostgreSQL using Docker Compose.

Learning Objectives

• Build and run a Python web app in Docker.
• Configure a PostgreSQL service in a separate container.
• Connect FastAPI to PostgreSQL using SQLAlchemy.
• Verify service health with an API endpoint.

Tech Stack

• Python 3.10+
• FastAPI
• Uvicorn
• SQLAlchemy
• PostgreSQL 15 (Alpine)
• Docker & Docker Compose

Project Structure

.
├── main.py
├── requirements.txt
├── Dockerfile
├── docker-compose.yml
├── conf/
│   └── db.py
├── static/
└── templates/

API Endpoints

• GET / — renders HTML template.
• GET /healthchecker — checks database connectivity (SELECT 1).

Run Locally (without Docker)

1. Create and activate a virtual environment:

python3 -m venv .venv
source .venv/bin/activate

2. Install dependencies:

pip install -r requirements.txt

3. Make sure PostgreSQL is running and available at:

postgresql+psycopg2://postgres:567234@localhost:5432/hw02

Or set your own URL:

export DATABASE_URL="postgresql+psycopg2://<user>:<password>@<host>:<port>/<db_name>"

4. Start the app:

python main.py

5. Open:

• http://localhost:8000/
• http://localhost:8000/healthchecker

Run with Docker Compose

Build and start services:

docker compose up -d --build

Check status:

docker compose ps

Check DB health endpoint:

curl -i http://localhost:8000/healthchecker

Stop services:

docker compose down

Notes

• Database URL is read from DATABASE_URL in conf/db.py.
• If DATABASE_URL is not provided, local fallback is used: postgresql+psycopg2://postgres:567234@localhost:5432/hw02.
• Inside Docker Compose, the DB host must be the service name: db_postgres.

Course Context

This repository demonstrates practical skills for the Docker topic in a Python Web lesson: containerizing a backend service, connecting multi-container services, and validating runtime connectivity.