FitTrack — User Service

Authentication and user-profile microservice for the FitTrack platform. Handles registration, login, JWT issuance and validation, and publishes user.created events to RabbitMQ so downstream services (activity, AI recommendation, etc.) can react.

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Tech stack

Layer	Choice
Language	Java 21
Framework	Spring Boot 4.0.2 (Web MVC, Data JPA, Security, AOP, Validation)
Auth	Spring Security + JWT (jjwt 0.12.5), BCrypt
Persistence	PostgreSQL via Spring Data JPA / Hibernate
Messaging	RabbitMQ (AMQP starter, topic exchange)
Service registry	Netflix Eureka client (Spring Cloud 5.0.0)
Config / secrets	AWS SSM Parameter Store (ap-south-1)
AI (optional)	Spring AI — Ollama starter
Build	Maven, Lombok

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Architecture overview

            ┌────────────────┐         ┌──────────────────┐
  client ──▶│  user-service  │◀────────│  Eureka registry │
            │  (port 8071)   │         └──────────────────┘
            └───────┬────────┘
                    │ JPA
                    ▼
            ┌────────────────┐
            │  PostgreSQL    │
            └────────────────┘
                    │ AMQP publish (user.created)
                    ▼
            ┌────────────────┐
            │   RabbitMQ     │──▶ activity-service, ai-service, …
            └────────────────┘

  Secrets pulled at startup from AWS SSM Parameter Store
  (DB credentials, JWT secret, RabbitMQ addresses).

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API

Base URL: http://localhost:8071

Auth — /api/auth/** (public)

Method	Path	Description
POST	/api/auth/register	Create a user, issue JWT, publish event
POST	/api/auth/login	Authenticate and issue JWT
GET	/api/auth/validateToken	Validate Authorization: Bearer <token>

Register / Login request

{
  "email": "sachin@example.com",
  "password": "secret123",
  "firstName": "Sachin",
  "lastName": "Gupta"
}

Auth response

{
  "status": "SUCCESS",
  "message": "Login successful",
  "data": {
    "token": "eyJhbGciOi...",
    "userId": 1,
    "email": "sachin@example.com",
    "firstName": "Sachin",
    "lastName": "Gupta",
    "role": "USER"
  }
}

Users — /api/users/** (JWT required)

Method	Path	Auth	Description
GET	/api/users/{userId}	ROLE_USER	Fetch user profile
GET	/api/users/{userId}/validate	Authenticated	Check if a user exists

Send the JWT as Authorization: Bearer <token>.

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Events published

On successful registration, a message is published to:

• Exchange: fitness_exchange (topic)
• Routing key: user_routing_key
• Queue (bound): user_queue
• Payload: UserSavedDTO — id, email, firstName, lastName, role, createdAt, updatedAt (JSON, ISO-8601 timestamps).

The RabbitMQ ConnectionFactory is built from the SSM-resolved URI at startup; TLS is enabled automatically when the scheme is amqps:// (works out-of-the-box with CloudAMQP).

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Configuration

src/main/resources/application.yaml resolves most sensitive values from AWS SSM Parameter Store under /Fittrack/*. Make sure the runtime has AWS credentials with ssm:GetParameter for these paths:

SSM parameter	Used for
/Fittrack/postgres-db/url	JDBC URL
/Fittrack/postgres-db/username	DB username
/Fittrack/postgres-db/password	DB password
/Fittrack/jwt/secret	JWT signing key
/Fittrack/jwt/expiration	Token TTL (ms)
/Fittrack/rabbitmq/uri	Full RabbitMQ URI (e.g. amqps://user:pass@host/vhost)

Other defaults:

• server.port — 8071
• eureka.client.service-url.defaultZone — http://localhost:8761/eureka/
• aws.ssm.region — ap-south-1

Provide AWS credentials via the standard chain (env vars, ~/.aws/credentials, IAM role on EC2/ECS, etc.).

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Running locally

Prerequisites

• Java 21, Maven 3.9+
• PostgreSQL reachable from the SSM-provided URL
• RabbitMQ reachable from the SSM-provided addresses
• A running Eureka server at localhost:8761
• AWS credentials with read access to the SSM parameters above

Build & run

# from the project root
./mvnw clean package
./mvnw spring-boot:run

Or run the jar directly:

java -jar target/user-service-0.0.1-SNAPSHOT.jar

The service registers itself with Eureka as user-service and listens on :8071.

Tests

./mvnw test

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Project layout

src/main/java/com/fitness/user_service
├── UserServiceApplication.java
├── aspect/             # AOP logging
├── config/             # Security, JWT filter, RabbitMQ, SSM, DB
├── controllers/        # AuthController, UserController
├── dto/                # Request/response DTOs + GlobalResponseDTO wrapper
├── exceptions/         # GlobalExceptionHandler, JwtAuthenticationException
├── model/              # User entity (UserDetails), UserRole enum
├── repository/         # UserRepository (Spring Data JPA)
└── service/            # AuthService, UserService, JwtService, ParameterStoreService

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Notes

• Sessions are stateless — every request is authenticated via the JWT filter (JwtAuthenticationFilter) ahead of UsernamePasswordAuthenticationFilter.
• hibernate.ddl-auto=update is convenient for dev but should be replaced with Flyway/Liquibase for any non-local environment.
• Method-level authorization is enabled (@EnableMethodSecurity); use @PreAuthorize on controller methods.