服务网关与API网关：核心区别解析及微服务实践指南

# API网关配置示例（Kong）
services:
  - name: product-api
    url: http://service-gateway:8080
    plugins:
      - name: rate-limiting
        config:
          minute: 1000
      - name: key-auth
      - name: cors
        config:
          origins: ["https://mall.example.com"]
          
routes:
  - name: product-route
    service: product-api
    paths: ["/api/v1/products"]
    methods: ["GET", "POST"]
    strip_path: true

# 服务网关配置示例（Spring Cloud Gateway）
spring:
  cloud:
    gateway:
      routes:
        - id: product-service
          uri: lb://product-service
          predicates:
            - Path=/products/**
          filters:
            - name: CircuitBreaker
              args:
                name: productService
                fallbackUri: forward:/fallback/product
            - name: Retry
              args:
                retries: 3
                backoff:
                  firstBackoff: 50ms
                  maxBackoff: 500ms

// API网关安全过滤器示例
@Component
public class SecurityGatewayFilter implements GlobalFilter {
    
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpRequest request = exchange.getRequest();
        
        // 1. JWT令牌验证
        String token = extractToken(request);
        if (!validateJWT(token)) {
            return handleUnauthorized(exchange);
        }
        
        // 2. API密钥验证
        String apiKey = request.getHeaders().getFirst("X-API-Key");
        if (!validateApiKey(apiKey)) {
            return handleForbidden(exchange);
        }
        
        // 3. 请求签名验证
        String signature = request.getHeaders().getFirst("X-Signature");
        if (!validateSignature(request, signature)) {
            return handleBadRequest(exchange);
        }
        
        return chain.filter(exchange);
    }
}

# 服务网关限流配置
resilience4j:
  ratelimiter:
    instances:
      productService:
        limitForPeriod: 1000
        limitRefreshPeriod: 1s
        timeoutDuration: 0s
      orderService:
        limitForPeriod: 500
        limitRefreshPeriod: 1s
        timeoutDuration: 0s
        
  circuitbreaker:
    instances:
      productService:
        failureRateThreshold: 50
        waitDurationInOpenState: 10s
        slidingWindowSize: 100
        minimumNumberOfCalls: 20

// 使用TRAE IDE开发自定义网关过滤器
@Component
export class CustomGatewayFilter implements GatewayFilter {
    
    // TRAE IDE会智能提示GatewayFilter接口的所有方法
    filter(exchange: ServerWebExchange, chain: GatewayFilterChain): Mono<void> {
        const request = exchange.getRequest;
        
        // IDE会提供ServerHttpRequest的所有可用方法提示
        const path = request.getURI().getPath();
        const headers = request.getHeaders();
        
        // 智能代码补全会显示可用的HTTP方法
        if (request.getMethod() === HttpMethod.GET) {
            // 实现缓存逻辑
            return this.handleCache(exchange, chain);
        }
        
        return chain.filter(exchange);
    }
}

// 网关性能监控代码示例
const performanceMonitor = {
    
    // 记录请求开始时间
    startTimer: (requestId) => {
        console.time(`request_${requestId}`);
        return Date.now();
    },
    
    // 记录各个阶段的耗时
    recordPhase: (requestId, phase, duration) => {
        console.log(`[${requestId}] ${phase}: ${duration}ms`);
        
        // TRAE IDE的调试控制台会以结构化方式显示这些日志
        // 便于分析性能瓶颈
        if (duration > 100) {
            console.warn(`⚠️ 性能警告: ${phase} 耗时过长`);
        }
    },
    
    // 结束监控
    endTimer: (requestId) => {
        console.timeEnd(`request_${requestId}`);
    }
};

# 网关性能优化配置
optimization:
  # 启用响应缓存
  response-cache:
    enabled: true
    ttl: 300s
    
  # 连接池优化
  connection-pool:
    max-connections: 1000
    acquire-timeout: 5s
    
  # 异步处理
  async:
    enabled: true
    thread-pool-size: 200

// 网关健康检查端点
@RestController
@RequestMapping("/gateway/health")
public class GatewayHealthController {
    
    @GetMapping("/status")
    public ResponseEntity<Map<String, Object>> getHealthStatus() {
        Map<String, Object> status = new HashMap<>();
        
        // 检查各个组件状态
        status.put("api-gateway", checkApiGateway());
        status.put("service-gateway", checkServiceGateway());
        status.put("registry", checkServiceRegistry());
        status.put("timestamp", System.currentTimeMillis());
        
        return ResponseEntity.ok(status);
    }
}