Dockerized FastAPI Application

This project provides a solution for a machine test to dockerize a simple FastAPI application. The application exposes a few endpoints to interact with a JSON file, and the entire setup can be managed using Docker Compose.

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🚀 Project Overview

The goal was to containerize a basic FastAPI application and ensure it can be run and managed with docker-compose. A key requirement was to persist user data in a users.json file, even after the containers are shut down and restarted.

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🛠️ Technology Stack

• FastAPI: A modern, fast (high-performance) web framework for building APIs with Python 3.7+.
• Docker: A platform for developing, shipping, and running applications in containers.
• Docker Compose: A tool for defining and running multi-container Docker applications.

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📂 Project Structure

.
├── app/
│   ├── main.py
│   └── users.json
├── data/
│   └── users.json
├── docker-compose.yml
├── Dockerfile
├── images/
│   ├── docker compse down and up.png
│   ├── fast api.png
│   ├── hello message.png
│   ├── user data after compose up and down.png
│   └── user data.png
└── requirements.txt

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📋 How to Run the Application

Prerequisites

• Docker: Ensure Docker is installed on your system.
• Docker Compose: Ensure Docker Compose is installed.

Steps

1. Clone this repository to your local machine:

   git clone [https://github.com/govindkotalwar8/docker-fastapi-test.git](https://github.com/govindkotalwar8/docker-fastapi-test.git)
   cd docker-fastapi-test

2. Build and run the containers using Docker Compose:

   docker-compose up --build

   This command will build the Docker image and start the FastAPI application in a container. The -d flag can be used to run in detached mode (docker-compose up -d).

3. The application will be accessible at http://localhost:8000. You can test the API endpoints using the interactive documentation at http://localhost:8000/docs.

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🎯 API Endpoints

The application provides the following endpoints:

Method	Endpoint	Description
GET	/	Returns a simple "Hello" message.
GET	/users	Returns a list of users stored in the data/users.json file.
POST	/users	Accepts new user data and appends it to the data/users.json file.

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📸 Screenshots

To demonstrate the application's functionality and persistence, here are screenshots showing key steps.

Initial API Access (/docs)

This shows the interactive API documentation provided by FastAPI.

The "Hello" Message Endpoint

A successful response from the root endpoint.

Adding a User

A screenshot showing data being posted to the /users endpoint.

Data Persistence After Restart

This screenshot proves that the user data is correctly stored and persists even after the container is shut down and brought back up, fulfilling a key project requirement.

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✅ Task Completion

• Application Containerization: The FastAPI application is successfully containerized using a Dockerfile.
• Docker Compose Integration: A docker-compose.yml file is provided to orchestrate the application and its dependencies.
• Data Persistence: The users.json file is correctly mounted as a volume, ensuring that user data is not lost when the container is stopped or restarted. This is verified by the screenshot of data persisting after a docker-compose down and up cycle.

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This project was completed as part of a machine test for Nimap Infotech.

![FastAPI Interactive Documentation](images/fast api.png)
![Hello Message](images/hello message.png)
![User Data](images/user data.png)
![User Data After Compose Restart](images/user data after compose up and down.png)