A scalable and tamper-proof event logging platform designed for distributed applications. This system provides RESTful APIs for logging and querying events, supports real-time updates via WebSocket, and includes a basic frontend for interaction.

• Event Logging API: Log events with metadata like event type, timestamp, source application ID, and payload.
• Tamper-Proof Design: Events are chained with cryptographic hashes for integrity.
• Search and Query: Filter events by type, source, and date range.
• Real-Time Updates: WebSocket support for real-time log streaming.
• Basic Frontend: Simple interface to log and view events.
• Scalability: Designed to handle large datasets with MongoDB's indexing.

• Node.js: Server-side runtime.
• Express.js: Web framework.
• MongoDB: NoSQL database.
• WebSocket: Real-time updates.
• Crypto: Cryptographic hashing.

• HTML, CSS, JavaScript: Basic user interface.

event-logging-system/
│
├── backend/
│   ├── app.js               # Main server entry point
│   ├── routes/
│   │   ├── events.js        # API routes for events
│   │   └── real_time.js     # WebSocket route
│   ├── models/
│   │   └── Event.js         # Mongoose schema
│   ├── utils/
│   │   └── hashUtils.js     # Hashing utility functions
│   ├── config/
│   │   └── db.js            # MongoDB connection
│   ├── package.json         # Node.js dependencies
│   └── .env                 # Environment variables
│
├── frontend/
│   ├── index.html           # Frontend HTML
│   ├── style.css            # Frontend CSS
│   ├── script.js            # Frontend JavaScript
│
└── README.md                # Project Documentation

• Node.js (v14 or higher)
• MongoDB (Ensure MongoDB is running locally or use a cloud instance)
• Web browser (for the frontend)

1. Navigate to the backend folder:

   cd backend

2. Install dependencies:

   npm install

3. Create a .env file:

   touch .env

   Add the following content to the .env file:

   PORT=5000
   MONGO_URI=mongodb://localhost:27017/event_logging
   

4. Start the server:

   node app.js

The backend will run at http://localhost:5000.

1. Navigate to the frontend folder.
2. Open index.html in your browser.

Log a new event.

{
  "eventType": "user_login",
  "timestamp": "2024-11-21T12:34:56Z",
  "sourceAppId": "APP001",
  "payload": {
    "userId": "123",
    "ipAddress": "192.168.1.1"
  }
}

{
  "message": "Event logged successfully!",
  "data": {
    "eventType": "user_login",
    "timestamp": "2024-11-21T12:34:56Z",
    "sourceAppId": "APP001",
    "payload": { "userId": "123", "ipAddress": "192.168.1.1" },
    "previousHash": "0",
    "currentHash": "abc123..."
  }
}

Query events by filters.

• eventType (optional)
• sourceAppId (optional)
• startDate (optional, e.g., 2024-11-20T00:00:00Z)
• endDate (optional, e.g., 2024-11-21T23:59:59Z)

{
  "count": 2,
  "data": [
    {
      "eventType": "user_login",
      "timestamp": "2024-11-21T12:34:56Z",
      "sourceAppId": "APP001",
      "payload": { "userId": "123", "ipAddress": "192.168.1.1" },
      "previousHash": "0",
      "currentHash": "abc123..."
    }
  ]
}

• Log Event: Click "Log Event" to log a new event (predefined data).
• View Events: Click "View Events" to fetch and display all logged events.

Enable real-time logging with WebSocket:

1. Use a WebSocket client like wscat:

   wscat -c ws://localhost:5000

2. Monitor real-time event streams.

• Implement a dashboard for better event visualization.
• Add support for distributed logging.
• Enhance real-time features with client-side integration.

1. Fork the repository.
2. Create a new branch (feature/your-feature).
3. Commit your changes.
4. Push to your branch.
5. Create a pull request.

This project is licensed under the MIT License.