spring:
  cloud:
    gateway:
      routes:
        # 灰度路由（高優(yōu)先級(jí)）
        - id: user-service-gray
          uri: lb://user-service
          predicates:
            - Path=/api/user/**
            - Header=X-Gray-Release, true # 當(dāng)請(qǐng)求頭包含 X-Gray-Release: true 時(shí)匹配
          filters:
            - AddRequestHeader=X-Request-Version, v2 # 可為下游服務(wù)添加標(biāo)識(shí)
          order: 0 # 優(yōu)先級(jí)高于默認(rèn)路由
        # 默認(rèn)路由（兜底）
        - id: user-service-default
          uri: lb://user-service
          predicates:
            - Path=/api/user/**
          order: 1

spring:
  cloud:
    gateway:
      routes:
        - id: weight_high
          uri: lb://user-service-v1
          predicates:
            - Path=/api/order/**
            - Weight=user-service-group, 80 # 80%流量到v1
        - id: weight_low
          uri: lb://user-service-v2
          predicates:
            - Path=/api/order/**
            - Weight=user-service-group, 20 # 20%流量到v2

@Component
@Order(-1)
public class GrayUserFilter implements GlobalFilter {
    // 假設(shè)這是灰度用戶名單
    private final Set<String> grayUsers = Set.of("1001", "1002", "1005"); 
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        String userId = exchange.getRequest().getHeaders().getFirst("X-User-ID");
        if (grayUsers.contains(userId)) {
            // 將用戶標(biāo)記為灰度用戶，后續(xù)可通過自定義斷言路由
            exchange.getAttributes().put("GRAY_TAG", true);
        }
        return chain.filter(exchange);
    }
}