Zuul(Router and Filter)

WIKI: Portal

Effect

1. Authentication/Security
2. Insights
3. Stress Testing
4. Canary Testing
5. Dynamic Routing
6. Service Migration
7. Load Shedding
8. Static Response handling
9. Active/Active traffic management

Key configurations:

The configuration property zuul.host.maxTotalConnections and zuul.host.maxPerRouteConnections, which default to 200 and 20 respectively.

Create mscx-ad-zuul

The method of creating trilogy:

Add dependency

    <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>

append notes to

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

Modified configuration

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: '*' # Filter all requests except the services declared in routes below
  routes:
    sponsor: #Customize service routing name in routing
      path: /ad-sponsor/**
      serviceId: mscx-ad-sponsor #Microservice name
      strip-prefix: false
    search: #Customize service routing name in routing
      path: /ad-search/**
      serviceId: mscx-ad-search #Microservice name
      strip-prefix: false
  prefix: /gateway/api
  strip-prefix: false #Instead of intercepting the path set by prefix: /gateway/api, default forwarding intercepts the prefix of the configuration

Filter compilation

Let's write a filter to record the request time period. According to the three types of filters: Pre filters,routing filters and Post filters, we need to define two filters to record the start and end times. Obviously, we need to implement Pre & Post two filters.

@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 {
        //Get the request context of the current request
        RequestContext requestContext = RequestContext.getCurrentContext();
        //Record request entry time
        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() {
        //filter that needs the last execution
        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