API 网关

路由表
链路追踪

1.1 网关的作用

路由：接口服务的统一代理，实现前端对接口的统一访问
过滤：对用户请求进行拦截、过滤（用户鉴权）、监控
限流：限制用户的访问流量

1.2 常用网关

Nginx
Spring Cloud Netflix zuul
Spring Cloud Gateway

2. Zuul 网关

路由转发
过滤器

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
    </dependency>
</dependencies>

application.yml

zuul:
  routes:
    api:
      path: /api/**
      serviceId: concrete-eureka-client # spring.application.name
    apiB:
      path: /api/b/**
      serviceId: concrete-feign

增加注解 @EnableZuulProxy
@EnableZuulProxy 是 @EnableZuulServer 的增强升级版

@SpringBootApplication
@EnableEurekaClient
@EnableZuulProxy
public class ConcreteZuulApplication {
    public static void main(String[] args) {
        SpringApplication.run(ConcreteZuulApplication.class, args);
    }
}

报错：
java.lang.NoSuchMethodError: org.springframework.boot.web.servlet.error.ErrorController.getErrorPath()Ljava/lang/String;
zuul 版本与 Spring Cloud 版本冲突