Workload Service

A microservice for tracking trainer monthly workload in the Gym CRM System.

Description

Workload Service accepts information about trainings (add/delete) and calculates the total working hours for each trainer by month. Data is stored in an in-memory structure for fast access.

Features

• ✅ REST API for adding/deleting trainer workload
• ✅ In-memory data storage (ConcurrentHashMap)
• ✅ JWT Bearer Token authorization
• ✅ Eureka Discovery Service registration
• ✅ Two-level logging (Transaction + Operation)
• ✅ Circuit Breaker (Resilience4j)
• ✅ Actuator endpoints for monitoring
• ✅ Prometheus metrics

Tech Stack

• Java 17
• Spring Boot 3.5.3
• Spring Cloud (Eureka Client)
• Spring Security + JWT
• Resilience4j
• Lombok
• SLF4J/Logback

Project Structure

workload-service/
├── src/main/java/abu/epam/com/workloadservice/
│   ├── config/          # Configuration (Security)
│   ├── controller/      # REST Controllers
│   ├── dto/             # Data Transfer Objects
│   ├── filter/          # Filters (Logging, Transaction)
│   ├── model/           # Data Models
│   ├── security/        # JWT components
│   └── service/         # Business Logic
└── src/main/resources/
    ├── application.yml      # Application configuration
    └── logback-spring.xml   # Logging configuration

API Endpoints

1. Update Trainer Workload

POST /api/workload
Authorization: Bearer <JWT_TOKEN>
Content-Type: application/json

{
  "username": "john.doe",
  "firstName": "John",
  "lastName": "Doe",
  "isActive": true,
  "trainingDate": "2024-02-08",
  "trainingDuration": 60,
  "actionType": "ADD"
}

Field Descriptions:

• username - Trainer's unique username
• firstName - Trainer's first name
• lastName - Trainer's last name
• isActive - Trainer's active status
• trainingDate - Training date
• trainingDuration - Training duration (in minutes)
• actionType - Action type: ADD or DELETE

Response:

• 200 OK - Workload updated successfully
• 400 Bad Request - Validation error
• 401 Unauthorized - Missing or invalid JWT token

2. Get Specific Trainer Workload

GET /api/workload/{username}
Authorization: Bearer <JWT_TOKEN>

Response:

{
  "username": "john.doe",
  "firstName": "John",
  "lastName": "Doe",
  "isActive": true,
  "years": {
    "2024": {
      "months": {
        "1": {
          "totalDuration": 120
        },
        "2": {
          "totalDuration": 180
        }
      }
    }
  }
}

3. Get All Trainers Workload

GET /api/workload
Authorization: Bearer <JWT_TOKEN>

Configuration

Ports

• Application: 8082
• Eureka Server: 8761 (default)

JWT Secret

Default: MySecretKeyForJWTTokenGenerationAndValidationPurpose12345

To change, update in application.yml:

jwt:
  secret: YOUR_SECRET_KEY

Eureka Configuration

eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka/

Running the Service

Requirements

1. JDK 17+
2. Maven 3.6+
3. Eureka Server (should be running on port 8761)

Build and Run

# Build the project
mvn clean package

# Run the application
mvn spring-boot:run

# Or run the JAR file
java -jar target/workload-service-0.0.1-SNAPSHOT.jar

API Documentation

Swagger UI

Access interactive API documentation at:

• Swagger UI: http://localhost:8082/swagger-ui.html
• OpenAPI Spec: http://localhost:8082/v3/api-docs

The Swagger UI provides:

• Interactive API testing
• Request/response examples
• Schema definitions
• JWT authentication testing (click "Authorize" button and enter your JWT token)

Monitoring

Actuator Endpoints

• Health: http://localhost:8082/actuator/health
• Metrics: http://localhost:8082/actuator/metrics
• Prometheus: http://localhost:8082/actuator/prometheus

Logging

Two-Level Logging

Transaction Level

HTTP request/response logging with unique transactionId generation:

2024-02-08 10:30:45.123 [http-nio-8082-exec-1] INFO  [TxId: abc-123-def] [TRANSACTION] START - Method: POST, URI: /api/workload
2024-02-08 10:30:45.456 [http-nio-8082-exec-1] INFO  [TxId: abc-123-def] [TRANSACTION] END - Status: 200, Duration: 333ms

Operation Level

Detailed logging of operations within the transaction:

2024-02-08 10:30:45.234 [http-nio-8082-exec-1] DEBUG [TxId: abc-123-def] [OPERATION] Request Body: {...}
2024-02-08 10:30:45.345 [http-nio-8082-exec-1] INFO  [TxId: abc-123-def] Processing workload for trainer: john.doe

Log Files

Logs are saved to:

• Console output
• logs/workload-service.log
• Rotation: daily, retention 30 days

Circuit Breaker

Resilience4j Circuit Breaker configured with:

• Sliding Window Size: 10 requests
• Failure Rate Threshold: 50%
• Wait Duration in Open State: 5 seconds
• Minimum Number of Calls: 5

Integration with Gym CRM System

Workload Service is designed to be called from the main Gym-CRM-system when:

• Creating a new training (actionType: ADD)
• Deleting a training (actionType: DELETE)

Security

JWT Authentication

All API endpoints (except actuator) are protected with JWT authentication.

For access:

1. Obtain JWT token from the main Gym-CRM-system
2. Add token to header: Authorization: Bearer <token>

Usage Examples

cURL

# Add training
curl -X POST http://localhost:8082/api/workload \
  -H "Authorization: Bearer YOUR_JWT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "username": "john.doe",
    "firstName": "John",
    "lastName": "Doe",
    "isActive": true,
    "trainingDate": "2024-02-08",
    "trainingDuration": 60,
    "actionType": "ADD"
  }'

# Get trainer workload
curl -X GET http://localhost:8082/api/workload/john.doe \
  -H "Authorization: Bearer YOUR_JWT_TOKEN"

Troubleshooting

Service not registering with Eureka

1. Check that Eureka Server is running on localhost:8761
2. Check logs for connection errors
3. Ensure eureka.client.register-with-eureka=true

JWT token validation fails

1. Ensure you're using the correct secret key
2. Check token format: Bearer <token>
3. Verify token expiration

Data not persisting

The service uses in-memory storage. All data is lost on restart. This is expected behavior according to requirements.

License

Developed as part of EPAM Specialization Program.