API Gateway with Spring Cloud Gateway

The API Gateway is an essential component of a microservices architecture. It serves as a single entry point for all clients and handles important concerns such as routing, security, and rate limiting.

1. API Gateway Configuration

1.1 Creating the Gateway Project

curl https://start.spring.io/starter.tgz \
    -d dependencies=cloud-gateway,cloud-eureka-client \
    -d groupId=com.example \
    -d artifactId=api-gateway \
    -d name=api-gateway \
    -d description=API%20Gateway%20for%20Microservices \
    -d packageName=com.example.gateway \
    -d packaging=jar \
    -d javaVersion=17 \
    -d type=maven-project \
    | tar -xzvf -

1.2 Basic Configuration

# application.yml
server:
  port: 8080

spring:
  application:
    name: api-gateway
  cloud:
    gateway:
      discovery:
        locator:
          enabled: true
          lower-case-service-id: true
      routes:
        - id: product-service
          uri: lb://product-service
          predicates:
            - Path=/api/products/**
          filters:
            - StripPrefix=1
            - name: RequestRateLimiter
              args:
                redis-rate-limiter.replenishRate: 10
                redis-rate-limiter.burstCapacity: 20
                key-resolver: "#{@ipKeyResolver}"

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