simple-service

Simple Service Example

Complete microservice example using all laresto-go-common packages.

Features Demonstrated

• ✅ Logger: Structured logging
• ✅ Database: PostgreSQL connection
• ✅ Cache: Redis for caching and sessions
• ✅ Kafka: Event publishing
• ✅ JWT: Authentication with access/refresh tokens
• ✅ Validation: Request validation
• ✅ Middleware: Request ID, logging, recovery, CORS, error handling
• ✅ Tracing: Distributed tracing with OpenTelemetry
• ✅ Error Handling: Standardized error responses

Prerequisites

Start the LaResto infrastructure:

cd ../laresto-docker-compose
docker-compose up -d

Running the Service

cd examples/simple-service
go run main.go

The service will start on port 8080.

API Endpoints

Health Check

curl http://localhost:8080/health

Create User

curl -X POST http://localhost:8080/users \
  -H "Content-Type: application/json" \
  -d '{
    "email": "user@example.com",
    "password": "Password123",
    "name": "John Doe"
  }'

Get User

curl http://localhost:8080/users/user-123

Login

curl -X POST http://localhost:8080/login \
  -H "Content-Type: application/json" \
  -d '{
    "email": "user@example.com",
    "password": "Password123"
  }'

Get Profile (Protected)

# First login to get token
TOKEN=$(curl -X POST http://localhost:8080/login \
  -H "Content-Type: application/json" \
  -d '{"email":"user@example.com","password":"Password123"}' \
  | jq -r '.access_token')

# Then access protected endpoint
curl http://localhost:8080/api/profile \
  -H "Authorization: Bearer $TOKEN"

Environment Variables

# Service
PORT=8080
LOG_LEVEL=info
ENVIRONMENT=development

# Database
DB_HOST=localhost
DB_NAME=customer_db
DB_USER=laresto_app
DB_PASSWORD=laresto_app_dev_password

# Redis
REDIS_HOST=localhost
REDIS_PASSWORD=redis_dev_password

# Kafka
KAFKA_BROKER=localhost:9092

# JWT
JWT_ACCESS_SECRET=dev-access-secret
JWT_REFRESH_SECRET=dev-refresh-secret

# Tracing
TRACING_ENABLED=true
OTLP_ENDPOINT=localhost:4318

View Traces

Access Jaeger UI: http://localhost:16686

Search for traces from simple-service.

Architecture

HTTP Request
    ↓
Middleware (Request ID, Logging, Recovery)
    ↓
Validation (Request validation)
    ↓
Handler (Business logic)
    ↓
├─ Database (PostgreSQL queries)
├─ Cache (Redis operations)
└─ Kafka (Event publishing)
    ↓
Response (JSON with error handling)

Code Structure

• main.go: Service initialization and routing
• Dependencies: All laresto-go-common packages
• Middleware Stack: Production-ready middleware chain
• Error Handling: Standardized error responses
• Tracing: Full request lifecycle tracking

This example serves as a template for building LaResto microservices.