[Spring cloud 一步步实现广告系统] 3. 网关路由

Zuul（Router and Filter）

WIKI: 传送门

作用

1. 认证，鉴权（Authentication/Security）
2. 预判（Insights）
3. 压力测试（Stress Testing）
4. 灰度/金丝雀测试（Canary Testing）
5. 动态路由（Dynamic Routing）
6. 服务迁移（Service Migration）
7. 降低负载（Load Shedding）
8. 静态响应处理（Static Response handling）
9. 主动/主动交换管理（Active/Active traffic management）

关键配置：

The configuration property

zuul.host.maxTotalConnections

and

zuul.host.maxPerRouteConnections

, which default to 200 and 20 respectively.

创建

mscx-ad-zuul

三步曲创建法：

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

@SpringCloudApplication
@EnableZuulProxy //启用网关
public class GatewayApplication {
public static void main(String[] args) {
SpringApplication.run(GatewayApplication.class, args);
}
}

spring:
application:
name: ad-gateway-zuul
server:
port: 1111
eureka:
client:
service-url:
defaultZone: http://server1:7777/eureka/,http://server2:8888/eureka/,http://server3:9999/eureka/
instance:
hostname: ad-gateway-zuul
zuul:
ignored-services: '*' # 过滤所有请求，除了下面routes中声明过的服务
routes:
sponsor: #在路由中自定义服务路由名称
path: /ad-sponsor/**
serviceId: mscx-ad-sponsor #微服务name
strip-prefix: false
search: #在路由中自定义服务路由名称
path: /ad-search/**
serviceId: mscx-ad-search #微服务name
strip-prefix: false
prefix: /gateway/api
strip-prefix: false #不对 prefix: /gateway/api 设置的路径进行截取，默认转发会截取掉配置的前缀

我们来编写一个记录请求时间周期的过滤器，根据Filter的三种类型:

Pre filters

routing filters

Post filters

Pre

Post

@Slf4j
@Component
public class PreRequestFilter extends ZuulFilter {
@Override
public String filterType() {
// pre filter
return FilterConstants.PRE_TYPE;
}

@Override
public int filterOrder() {
return 0;
}

@Override
public boolean shouldFilter() {
return true;
}

@Override
public Object run() throws ZuulException {
//获取当前请求的请求上下文
RequestContext requestContext = RequestContext.getCurrentContext();
//记录请求进入时间
requestContext.set("api_request_time", System.currentTimeMillis());
return null;
}
}

---

@Slf4j
@Component
public class AccessLogFilter extends ZuulFilter {

@Override
public String filterType() {
return FilterConstants.POST_TYPE;
}

@Override
public int filterOrder() {
//需要最后一个执行的filter
return FilterConstants.SEND_RESPONSE_FILTER_ORDER - 1;
}

@Override
public boolean shouldFilter() {
return true;
}

@Override
public Object run() throws ZuulException {
RequestContext requestContext = RequestContext.getCurrentContext();
HttpServletRequest request = requestContext.getRequest();
log.info("Request \"{}\" spent : {} seconds.", request.getRequestURI(),
(System.currentTimeMillis() - Long.valueOf(requestContext.get("api_request_time").toString())) / 1000);
return null;
}
}

Gateway

后续更新