Mock Server (Rust)

Overview

This project is a dynamic mock server written in Rust. It reads a YAML configuration file to define API endpoints, supported HTTP methods, and response files. The main goal is to provide a simple, file-based mock API server that supports:

• GET requests: Returns JSON responses from predefined files.
• POST & PUT requests: Saves incoming request bodies as JSON files.
• DELETE requests: Responds with HTTP 204 No Content.
• Local file storage only: All response files are stored in the responses/ directory.

Why This Project?

Many developers need quick and flexible mock servers to simulate backend APIs during frontend or integration testing. This project provides a lightweight and fast alternative to heavy solutions like JSON Server or WireMock.

Features

• 🚀 Fast: Uses warp and tokio for high-performance asynchronous processing.
• 📜 Easy Configuration: Define endpoints via a simple config.yaml file.
• 💾 File-Based Storage: Store and retrieve JSON responses without a database.
• 🔄 Dynamic API Handling: Automatically updates responses with POST/PUT.
• 🌍 CORS Support: Configured to allow cross-origin requests, making it easier to integrate with frontend applications.
• 🛠 Unit-Tested: Includes tests for configuration loading and request handling.
• 🔐 Authorization: Supports mocking of Basic Authentication and Bearer Token Authentication:
  • Basic Auth: Validates username and password based on the configuration.
  • Bearer Token: Validates tokens and their claims, ensuring that the token matches expected values and claims (e.g., roles, permissions).
• ⚙️ Custom Configuration:
  • Load a custom config.yaml file using a command-line argument (--file).
  • Set the server to listen on a custom port using --port.
  • Set a custom response folder location for the mockserver --responses-folder
• 📝 Logging: Enables detailed request logging for easier debugging.
• • ⏳ Configurable Delays: Simulate slow or rate-limited APIs by defining a delay field in config.yaml.
• Add an artificial delay (in milliseconds) before responding to requests.
• Useful for testing timeout handling and performance in client applications.
• ⏳ Configurable Delays: Simulate slow or rate-limited APIs by defining a delay field in config.yaml.
  • Add an artificial delay (in milliseconds) before responding to requests.
  • Useful for testing timeout handling and performance in client applications.
• 🚧 Rate Limiting: Control the number of requests allowed per endpoint within a specified time window:
  • Requests per window: Define the maximum number of requests allowed in a given time window (in milliseconds).
  • Separate counters per method: Rate limits are tracked separately for different HTTP methods (e.g., GET, POST).
  • 429 Too Many Requests: Returns a 429 status code when the rate limit is exceeded.

Installation

Download and Run

1. Download the latest release for Linux, Windows, or macOS from the Releases Page.
2. Extract the downloaded file.
3. Run the server with:

• Linux/macOS:

  ./mockserver --file config.yaml --port 8080 --responses-folder folder_location
  

• Windows (PowerShell) add the extension .exe and then run the following line:

  .\mockserver.exe --file config.yaml --port 8080 --responses-folder folder_location
  

4. Replace:

• config.yaml with your configuration file.
• 8080 with the desired port.
• folder_location with the directory for mock responses.

Configuration

/api/user:
  method: GET
  file: user_response.json
  authentication:
    basic:
      user: 'admin'
      password: 'secret'

/api/order:
  method: POST
  file: order_data.json
  status_code: 202 #custom Http status code
  authentication:
    bearer:
      token: 'valid_token'
      claims:
        role: 'admin'

This means:

• GET /api/user → Returns response/user_reponse.json
• POST /api/order → Returns response/order_data.json

Running the server

cargo run

Server starts on http://localhost:8080

Example Usage

Retrieve a mock Response

curl http://localhost:8080/api/user

Save/Update Data

curl -X POST http://localhost:8080/api/order -d '{"item": "Laptop"}' -H "Content-Type: application/json"

Delete Data

curl -X DELETE http://localhost:8080/api/order

Running Testss

cargo test

Contributions

Contributions are welcome! Feel free to submit issues or pull requests.

License

This project is licensed under the MIT License - see the full details at MIT License.