Gateway Service

Gateway Service Skill

Service Type: API Gateway

Central entry point for all API requests.

Responsibilities

• Request routing to backend services
• Authentication/Authorization (JWT validation)
• Rate limiting (Redis-based)
• Circuit breaker (Resilience4j)
• Request/Response logging
• CORS handling

Package Structure

com.company.gateway/
├── config/         # Security, CORS configuration
├── filter/         # Global filters (logging, auth)
└── fallback/       # Circuit breaker fallbacks

Key Components

Route Configuration

Routes are defined in application.yml:

• Path-based routing
• Circuit breaker per service
• Rate limiting per endpoint

Global Filters

• LoggingFilter: Logs all requests, adds trace ID
• AuthFilter: Validates JWT tokens (if needed)

Fallback Controller

Returns friendly error messages when services are down.

Adding New Route

# application.yml
spring:
  cloud:
    gateway:
      routes:
        - id: new-service
          uri: http://localhost:808X
          predicates:
            - Path=/api/new/**
          filters:
            - name: CircuitBreaker
              args:
                name: newService
                fallbackUri: forward:/fallback/default

Commands

# Run
mvn spring-boot:run

# Test routes
curl http://localhost:8080/api/users
curl http://localhost:8080/actuator/gateway/routes