🛰️ Kafka Schema Registry Microservices Demo

This project demonstrates an event-driven microservices architecture using Spring Boot, Apache Kafka, and Confluent Schema Registry.
It includes:

• Producer Service — generates sensor data and publishes events to Kafka (Avro format)
• Consumer Service — listens to Kafka and processes incoming sensor events
• Schema Registry — stores and manages Avro schemas
• Docker Compose — spins up Kafka, Schema Registry, and both services

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🧱 Project Structure

microservices-demo/
│
├── docker-compose.yml
├── producer-service/
│   ├── src/
│   ├── pom.xml
│   └── Dockerfile
│
├── consumer-service/
│   ├── src/
│   ├── pom.xml
│   └── Dockerfile
└── README.md

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⚙️ Requirements

Tool	Version	Description
Java	17+	Development runtime
Docker & Docker Compose	latest	Container management
Maven	(auto-managed via wrapper)	Dependency & build tool

You don’t need Maven installed globally — this project includes the Maven Wrapper (mvnw, mvnw.cmd).

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🧬 1. Generate Avro classes

Both services use Avro schemas stored under:

schema-registry/src/main/avro/

To generate Java classes from Avro:

./mvnw clean compile

Generated classes will appear under:

schema-registry/target/generated-sources/avro/

This step runs automatically during the normal build, but you can trigger it manually if you edit .avsc files.

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📦 2. Build & Package services

Build both services using:

./mvnw clean package -DskipTests

This will:

• Compile code and generated Avro classes
• Package each microservice as a runnable JAR inside its respective target/ folder

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🐳 3. Run everything with Docker Compose

From the project root:

docker-compose up --build

This will start:

• Zookeeper
• Kafka broker
• Schema Registry
• Producer Service
• Consumer Service

All services run on a shared Docker network.

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🌐 4. Useful URLs

Service	URL	Notes
Kafka Broker	localhost:9092	External access
Schema Registry	http://localhost:8081	REST API for schemas
Producer Service	http://localhost:8082	REST endpoint (if defined)
Consumer Service	http://localhost:8083	Listens for Kafka events

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🧠 Notes

• Both services share the same Avro schema to ensure compatibility.
• The producer uses KafkaAvroSerializer, and the consumer uses KafkaAvroDeserializer with specific.avro.reader=true.
• Each service uses its own Dockerfile to create independent containers.