📡 IoT Smart House – Secure Reactive System

A demonstration project of a secure, reactive IoT network for smart house environments. It showcases data ingestion, processing, monitoring, and bidirectional communication between simulated devices and a frontend web application.

🚀 Technologies Used

• Java 17, Spring Boot 3.4.3
• Reactive Kafka (reactor-kafka)
• Spring WebFlux
• Prometheus & Micrometer (metrics monitoring)
• Kafka UI (topic visualization)
• Docker & Docker Compose
• WebSocket (real-time frontend communication)

🏗️ System Architecture Overview

• Simulated IoT devices (e.g., temperature sensor, light bulb) send telemetry data to Kafka broker.
• A Kafka Consumer Service listens and processes incoming device messages.
• Messages are verified for authorization, processed, and optionally broadcast via WebSocket to connected clients.
• Commands from frontend apps are sent back to devices via a Kafka Command Producer.
• Prometheus tracks metrics such as:
  • success/failure rate
  • message processing duration
  • authorization failures

📁 Project Structure

📁 Project Structure

• devops/

  • dev-reset.sh – helper script to clean containers, build backend, and restart services.
  • docker-compose.yml – infrastructure setup with Kafka, Zookeeper, Kafka UI, and backend server.

• src/main/java/com.smartass.server/

  • config/
    • ReactiveKafkaProducerConfig – Kafka sender configuration.
    • ReactiveKafkaReceiverConfig – Kafka receiver configuration.
    • WebSocketConfig – WebSocket setup.
  • kafka/
    • KafkaCommandProducerService – sends commands to devices.
    • KafkaDeviceDataProducerService – sends simulated telemetry data.
    • KafkaDeviceDataConsumerService – receives and processes device data.
  • model/
    • command/ – DTOs for device commands.
    • device/ – domain models for device telemetry.
    • ErrorReason – error categorization enum.
  • registry/
    • DeviceDeserializerRegistry – mapping deserializers for device types.
  • security/
    • AuthKeyRegistry – manages authentication keys for devices.
  • service/
    • dispatch/
      • DeviceCommandDispatcher – forwards commands to Kafka.
    • processing/
      • DeviceProcessingService – processes validated telemetry.
    • simulator/
      • DeviceDataSimulatorService – runs selected simulators.
      • LightBulbSimulator
      • TemperatureSensorSimulator
      • Simulator – interface for simulators.
      • SimulatorProperties – config for retry/delay.
    • websocket/
      • DeviceCommandWebSocketHandler – WebSocket for command reception.
      • DeviceTelemetryWebSocketHandler – WebSocket for telemetry streaming.
  • ServerApplication – main Spring Boot entry point.

• Dockerfile – backend container definition.

• pom.xml – Maven configuration.

• README.md – documentation.

⚙️ Running the System

📦 Step-by-step Setup

1. Build and deploy the backend application:

cd devops
chmod +x scripts/build-restart.sh
./scripts/build-restart.sh