Realtime Gateway

Part of the Library Booking System.

WebSocket gateway service for real-time updates in the library booking system.

Overview

The Realtime Gateway provides WebSocket connections for real-time updates about:

• Resource availability changes
• Booking status updates
• System notifications

Features

• WebSocket server on port 3008
• RabbitMQ integration for event consumption
• Broadcasts real-time updates to connected clients
• Automatic reconnection to RabbitMQ on failure

Environment Variables

• PORT: WebSocket server port (default: 3008)
• RABBITMQ_HOST: RabbitMQ host (default: rabbitmq)
• RABBITMQ_PORT: RabbitMQ port (default: 5672)
• RABBITMQ_USER: RabbitMQ username (default: admin)
• RABBITMQ_PASS: RabbitMQ password (default: admin)

Building and Running

The service is automatically built and started with docker-compose:

cd docker-compose
docker-compose up -d realtime-gateway

Or build it separately:

cd realtime-gateway
docker build -t library-realtime-gateway .
docker run -p 3008:3008 library-realtime-gateway

WebSocket Protocol

Client Messages

Subscribe to updates:

{
  "type": "subscribe",
  "topic": "resource_123"
}

Server Messages

Availability update:

{
  "type": "availability_update",
  "resourceId": 123,
  "status": "available"
}

Connection confirmation:

{
  "type": "connected",
  "message": "Connected to realtime gateway"
}

Integration

The gateway is accessible via the API Gateway at:

• ws://localhost:8080/ws/ (when proxied through API Gateway)
• ws://localhost:3008 (direct connection)