User Management Server

A server app built using Shelf, designed to handle user registration and login functionality. The server is configured to be easily run locally or with Docker.

This project demonstrates a simple REST API that allows users to:

• Register (POST /register)
• Login (POST /login)

The user data is stored persistently in a JSON file on disk.

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Features

• User Registration: Users can register with a username and password.
• Login Authentication: Verify user credentials to authenticate requests.
• Data Persistence: User data is stored locally in a JSON file.
• Error Handling: Proper HTTP status codes for success and error responses.
• Logging: All incoming requests and responses are logged.

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Endpoints

POST /register

Registers a new user with a username and password.

• Request Body: JSON with username and password.
• Responses:
  • 200 OK: User successfully registered.
  • 400 Bad Request: Missing or empty username.
  • 409 Conflict: Username already exists.

Example:

$ curl -X POST http://0.0.0.0:8080/register \
  -H "Content-Type: application/json" \
  -d '{"username": "testuser", "password": "mypassword"}'

POST /login

Authenticates a user by checking the provided credentials.

• Request Body: JSON with username and password.
• Responses:
  • 200 OK: Login successful.
  • 400 Bad Request: Missing or empty username.
  • 401 Unauthorized: Invalid credentials.

Example:

$ curl -X POST http://0.0.0.0:8080/login \
  -H "Content-Type: application/json" \
  -d '{"username": "testuser", "password": "mypassword"}'

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Running the Server

Running with the Dart SDK

You can run the server locally with the Dart SDK:

1. Start the server:

   $ dart run bin/server.dart
   Server listening on port 8080

2. Use curl or a similar tool to test the API:

   $ curl -X POST http://0.0.0.0:8080/register \
     -H "Content-Type: application/json" \
     -d '{"username": "testuser", "password": "mypassword"}'
   
   $ curl -X POST http://0.0.0.0:8080/login \
     -H "Content-Type: application/json" \
     -d '{"username": "testuser", "password": "mypassword"}'

Running with Docker

If you have Docker Desktop installed, you can build and run the server using Docker:

1. Build the Docker image:

   $ docker build . -t userserver

2. Run the Docker container:

   $ docker run -it -p 8080:8080 userserver
   Server listening on port 8080

3. Test the API from another terminal:

   $ curl -X POST http://0.0.0.0:8080/register \
     -H "Content-Type: application/json" \
     -d '{"username": "testuser", "password": "mypassword"}'
   
   $ curl -X POST http://0.0.0.0:8080/login \
     -H "Content-Type: application/json" \
     -d '{"username": "testuser", "password": "mypassword"}'

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Logging

You can observe logs of incoming requests in the terminal running the server. For example:

2024-11-27T15:47:04.620417  0:00:00.000158 POST    [200] /register
2024-11-27T15:47:08.392928  0:00:00.001216 POST    [401] /login

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Requirements

• Dart SDK: Version 3.0 or later.
• Optional: Docker for containerized deployment.

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Future Enhancements

• Add token-based authentication (e.g., JWT).
• Implement HTTPS for secure communication.
• Replace JSON file storage with a database (e.g., SQLite or PostgreSQL).
• Add rate limiting to prevent abuse of the endpoints.

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This project is a simple starting point for understanding RESTful APIs in Dart and building user authentication systems.