version: '3.8'
services:
  # MQTT Broker (Edge Gateway)
  mosquitto:
    image: eclipse-mosquitto:latest
    ports: [ "1883:1883" ]
    volumes: [ "./mosquitto.conf:/mosquitto/config/mosquitto.conf" ]

  # Apache Kafka (KRaft mode - Resilience & Buffering)
  kafka:
    image: bitnami/kafka:latest
    ports: [ "9092:9092" ]
    environment:
      - KAFKA_CFG_NODE_ID=0
      - KAFKA_CFG_PROCESS_ROLES=controller,broker
      - KAFKA_CFG_LISTENERS=PLAINTEXT://:9092,CONTROLLER://:9093
      - KAFKA_CFG_CONTROLLER_QUORUM_VOTERS=0@kafka:9093

  # InfluxDB 2.0 (Time-Series Database for historical analysis)
  influxdb:
    image: influxdb:2.0
    ports: [ "8086:8086" ]
    environment:
      - DOCKER_INFLUXDB_INIT_MODE=setup
      - DOCKER_INFLUXDB_INIT_USERNAME=admin
      - DOCKER_INFLUXDB_INIT_PASSWORD=adminpassword
      - DOCKER_INFLUXDB_INIT_ORG=aerospace
      - DOCKER_INFLUXDB_INIT_BUCKET=telemetry

@Configuration
public class MqttIngestionConfig {

    private final KafkaTemplate<String, String> kafkaTemplate;

    public MqttIngestionConfig(KafkaTemplate<String, String> kafkaTemplate) {
        this.kafkaTemplate = kafkaTemplate;
    }

    @Bean
    public MessageChannel mqttInputChannel() { return new DirectChannel(); }

    @Bean
    public MqttPahoMessageDrivenChannelAdapter inbound() {
        MqttPahoMessageDrivenChannelAdapter adapter =
            new MqttPahoMessageDrivenChannelAdapter("tcp://localhost:1883", "ingest-client", "aircraft/+/telemetry");
        adapter.setConverter(new DefaultPahoMessageConverter());
        adapter.setQos(1); // At Least Once delivery guarantee
        adapter.setOutputChannel(mqttInputChannel());
        return adapter;
    }

    @Bean
    @ServiceActivator(inputChannel = "mqttInputChannel")
    public MessageHandler handler() {
        return message -> {
            String topic = message.getHeaders().get("mqtt_receivedTopic").toString();
            String payload = message.getPayload().toString();
            
            // Extract aircraft ID (e.g., aircraft/Boeing777-123/telemetry)
            String aircraftId = topic.split("/")[1];
            
            // Critical Buffering: Send to Kafka
            kafkaTemplate.send("flight-telemetry", aircraftId, payload);
            System.out.println("Queued in Kafka: " + aircraftId + " -> " + payload);
        };
    }
}

# deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: telemetry-ingest
  namespace: aviation-data
spec:
  replicas: 2 # Resilience: Active-Active Deployment
  template:
    metadata:
      annotations:
        # Critical line: Automatically injects the Istio network proxy
        sidecar.istio.io/inject: "true" 
    spec:
      containers:
      - name: telemetry-ingest
        image: your-registry/telemetry-ingest:latest
        ports:
        - containerPort: 8080

# mtls-policy.yaml
apiVersion: security.istio.io/v1beta1
kind: PeerAuthentication
metadata:
  name: default-strict-mtls
  namespace: aviation-data
spec:
  mtls:
    mode: STRICT # Zero Trust: Plain-text is prohibited

// Establish the relationship tree: Aircraft has Engines, which have Sensors
CREATE (a:Aircraft {id: 'B777-123'})
CREATE (e:Engine {id: 'ENG-1', position: 'Left'})
CREATE (s:Sensor {id: 'TEMP-01', type: 'Temperature'})
CREATE (a)-[:HAS_PART]->(e)
CREATE (e)-[:HAS_SENSOR]->(s)

@AiService
public interface MaintenanceAssistant {
    @SystemMessage({
        "You are an expert aviation maintenance AI for commercial aircraft.",
        "Analyze the sensor telemetry alert and cross-reference it with standard maintenance procedures.",
        "Provide a concise, 3-step action plan for the ground crew."
    })
    String analyzeAnomaly(@UserMessage String alertDescription);
}

import org.axonframework.modelling.command.TargetAggregateIdentifier;

// The Intent: A request to register an anomaly (The Write Model)
public record RegisterAnomalyCommand(
    @TargetAggregateIdentifier String anomalyId, 
    String aircraftId, 
    String sensorId, 
    String aiActionPlan
) {}

// The Fact: A factual, immutable record that history cannot erase (Audit Trail)
public record AnomalyRegisteredEvent(
    String anomalyId, 
    String aircraftId, 
    String sensorId, 
    String aiActionPlan
) {}

import org.axonframework.commandhandling.CommandHandler;
import org.axonframework.modelling.command.AggregateLifecycle;
import org.axonframework.spring.stereotype.Aggregate;

@Aggregate
public class MaintenanceAggregate {
    // Other fields (anomalyId, etc.)

    @CommandHandler // Handles the incoming Write request
    public MaintenanceAggregate(RegisterAnomalyCommand command) {
        // Validation logic here (if necessary)
        
        // If valid, apply (publish) the immutable event to the Axon Event Store
        AggregateLifecycle.apply(new AnomalyRegisteredEvent(
            command.anomalyId(), command.aircraftId(), command.sensorId(), command.aiActionPlan()
        ));
    }
}

import org.axonframework.eventhandling.EventHandler;
import org.springframework.stereotype.Component;

@Component
public class MaintenanceProjection {

    // Inject a standard JPA Repository here for dashboard queries

    @EventHandler // Listens to the immutable event, updates the dashboard view
    public void on(AnomalyRegisteredEvent event) {
        System.out.println("Updating Dashboard View for Anomaly: " + event.anomalyId());
        // repository.save(new MaintenanceDashboardRecord(event.anomalyId(), ...));
    }
}