Auth Service

This microservice is responsible for:

• Authenticating users via Keycloak
• Issuing and validating JWT tokens
• Producing Kafka user registration and logging events

---

Technologies

• Java 21
• Spring Boot 3.4.4
• Spring Security (OAuth2 Resource Server)
• Keycloak (external identity provider)
• Kafka (event-based communication)
• PostgreSQL + Liquibase (optional for local persistence)

---

Configuration (application.yml)

keycloak:
  realm: greenpulse
  auth-server-url: http://localhost:8180
  resource: greenpulseclient
  public-client: true
  bearer-only: true
  credentials:
    secret: ${KEYCLOAK_SECRET}
  admin:
    username: ${KEYCLOAK_ADMIN_USERNAME:admin}
    password: ${KEYCLOAK_ADMIN_PASSWORD:admin}

  security:
    oauth2:
      resourceserver:
        jwt:
          issuer-uri: http://localhost:8180/realms/greenpulse

Make sure to replace environment variables (e.g., KEYCLOAK_SECRET) in a secure way using .env.

---

Authorization Rules

All endpoints are secured with JWT tokens issued by Keycloak.

Roles such as ADMIN, MANAGER, and USER are extracted from:

realm_access.roles

Example JWT snippet:

"realm_access": {
  "roles": ["USER", "ADMIN"]
}

---

REST Endpoints

Method	Endpoint	Description
POST	/auth/register	Registering user
POST	/auth/login	Logging user

---

Kafka Integration

This service can produce Kafka events such as user registration and perform tasks like:

• Assigning roles
• Broadcasting registration to other services

---

Example DTO

{
  "id": "UUID",
  "username": "user",
  "email": "user@example.com",
  "status": "ENABLED",
  "roles": ["USER"]
}

---

Getting Started

Start Keycloak, PostgreSQL & Kafka

Run the service

./gradlew bootRun

Make sure Kafka, Keycloak and other dependencies are up and configured.

---

Useful Links

• Keycloak Admin REST API Docs
• Spring Security OAuth2 Resource Server
• JWT Debugger
• Docker Compose Reference
• Prometheus
• Grafana

---

TODOs

• Add unit tests for user role logic
• Add Swagger/OpenAPI documentation (optional)
• Monitoring

📄 License

This project is licensed under the Apache License 2.0.