Spring Cloud中怎么实现zuul网关服务

 <parent>
        <artifactId>spring-cloud-alibaba-basis</artifactId>
        <groupId>com.xian.cloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>cloud-gateway-zuul</artifactId>
    <name>网关服务zuul</name>

    <dependencies>
		<!-- 注册中心 -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
		<!-- 配置中心 -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-alibaba-nacos-config</artifactId>
        </dependency>
		<!-- fengin 支持 -->
       <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- zuul -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
        </dependency>
    </dependencies>

package com.xian.cloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.zuul.EnableZuulProxy;
import org.springframework.cloud.openfeign.EnableFeignClients;

/**
 * <Description>
 *
 * @author xianliru@100tal.com
 * @version 1.0
 * @createDate 2019/10/29 10:52
 */
@EnableZuulProxy
@EnableFeignClients
@EnableDiscoveryClient
@SpringBootApplication
public class GatewayZuulApplication {

    public static void main(String[] args) {
        SpringApplication.run(GatewayZuulApplication.class,args);
    }
}

spring:
  profiles:
    active: dev
  application:
    name: gateway-zuul-server
  cloud:
    nacos:
      config:
        server-addr: 47.99.209.72:8848
        file-extension: yaml

zuul:
  host:
    # 目标主机的最大连接数，默认值为200
    max-total-connections: 1000
    # 每个主机的初始连接数，默认值为20
    max-per-route-connections: 200
  routes:
    discovery-server:
      path: /server/**
      serviceId: cloud-discovery-server
    client-common:
      path: /client/**
      serviceId: cloud-discovery-client
      sensitiveHeaders: X-ABC,Authorization
  # 所有路由的默认Hystrix隔离模式（ExecutionIsolationStrategy）为SEMAPHORE。如果此隔离模式是首选，则zuul.ribbonIsolationStrategy可以更改为THREAD
  ribbon-isolation-strategy: thread
  # 这个属性意思，指定忽略的服务列表 * 代表忽略所有服务
  ignored-services: '*'
  # 字段比较敏感，不希望传递给下游微服务。 设置空没有要忽略的敏感字段。全部传给下游服务
  sensitive-headers: X-ABC
  ribbon:
    eager-load:
      # 强制加载，不设置会进行懒加载。spring 第一次请求会非常慢
      enabled: true
```



#### 参数
- zuul.host.max-total-connections 目标主机的最大连接数。
- zuul.host.max-per-route-connections 每个主机的初始连接数。

这个俩个参数是zuul的优化后的属性值，如果想有适合的配置，还需要根据业务情况而定

因为我们有俩个业务服务 一个服务提供者 一个是服务消费者我们配置俩个服务的分别路由 discovery-server、client-common
- path  是请求路径匹配规则
- serviceId 是我们服务的spring.application.name 对应的值。
- sensitiveHeaders 字段比较敏感，不希望传递给下游微服务。 设置空没有要忽略的敏感字段。全部传给下游服务这个字段可以是全局设置也可以是单个服务配置。
- ribbon-isolation-strategy 所有路由的默认Hystrix隔离模式（ExecutionIsolationStrategy）为SEMAPHORE。如果此隔离模式是首选，则zuul.ribbonIsolationStrategy可以更改为THREAD
-  ignored-services 忽略所有微服务，只路由指定的微服务。
-  ribbon.eager-load.enabled  true 强制加载 false 默认懒加载


true日志打印效果  false 将不打印这段日志

```
2019-10-29 23:47:11.377  INFO 61396 --- [           main] c.netflix.loadbalancer.BaseLoadBalancer  : Client: cloud-discovery-server instantiated a LoadBalancer: DynamicServerListLoadBalancer:{NFLoadBalancer:name=cloud-discovery-server,current list of Servers=[],Load balancer stats=Zone stats: {},Server stats: []}ServerList:null
2019-10-29 23:47:11.382  INFO 61396 --- [           main] c.n.l.DynamicServerListLoadBalancer      : Using serverListUpdater PollingServerListUpdater
2019-10-29 23:47:11.450  INFO 61396 --- [           main] c.netflix.config.ChainedDynamicProperty  : Flipping property: cloud-discovery-server.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647
2019-10-29 23:47:11.452  INFO 61396 --- [           main] c.n.l.DynamicServerListLoadBalancer      : DynamicServerListLoadBalancer for client cloud-discovery-server initialized: DynamicServerListLoadBalancer:{NFLoadBalancer:name=cloud-discovery-server,current list of Servers=[192.168.3.6:9012],Load balancer stats=Zone stats: {unknown=[Zone:unknown;	Instance count:1;	Active connections count: 0;	Circuit breaker tripped count: 0;	Active connections per server: 0.0;]
},Server stats: [[Server:192.168.3.6:9012;	Zone:UNKNOWN;	Total Requests:0;	Successive connection failure:0;	Total blackout seconds:0;	Last connection made:Thu Jan 01 08:00:00 CST 1970;	First connection made: Thu Jan 01 08:00:00 CST 1970;	Active Connections:0;	total failure count in last (1000) msecs:0;	average resp time:0.0;	90 percentile resp time:0.0;	95 percentile resp time:0.0;	min resp time:0.0;	max resp time:0.0;	stddev resp time:0.0]
]}ServerList:com.alibaba.cloud.nacos.ribbon.NacosServerList@33e4b9c4
2019-10-29 23:47:11.576  INFO 61396 --- [           main] c.netflix.config.ChainedDynamicProperty  : Flipping property: cloud-discovery-client.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647
2019-10-29 23:47:11.577  INFO 61396 --- [           main] c.netflix.loadbalancer.BaseLoadBalancer  : Client: cloud-discovery-client instantiated a LoadBalancer: DynamicServerListLoadBalancer:{NFLoadBalancer:name=cloud-discovery-client,current list of Servers=[],Load balancer stats=Zone stats: {},Server stats: []}ServerList:null
2019-10-29 23:47:11.578  INFO 61396 --- [           main] c.n.l.DynamicServerListLoadBalancer      : Using serverListUpdater PollingServerListUpdater
2019-10-29 23:47:11.639  INFO 61396 --- [           main] c.netflix.config.ChainedDynamicProperty  : Flipping property: cloud-discovery-client.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647
2019-10-29 23:47:11.640  INFO 61396 --- [           main] c.n.l.DynamicServerListLoadBalancer      : DynamicServerListLoadBalancer for client cloud-discovery-client initialized: DynamicServerListLoadBalancer:{NFLoadBalancer:name=cloud-discovery-client,current list of Servers=[192.168.3.6:9011],Load balancer stats=Zone stats: {unknown=[Zone:unknown;	Instance count:1;	Active connections count: 0;	Circuit breaker tripped count: 0;	Active connections per server: 0.0;]
},Server stats: [[Server:192.168.3.6:9011;	Zone:UNKNOWN;	Total Requests:0;	Successive connection failure:0;	Total blackout seconds:0;	Last connection made:Thu Jan 01 08:00:00 CST 1970;	First connection made: Thu Jan 01 08:00:00 CST 1970;	Active Connections:0;	total failure count in last (1000) msecs:0;	average resp time:0.0;	90 percentile resp time:0.0;	95 percentile resp time:0.0;	min resp time:0.0;	max resp time:0.0;	stddev resp time:0.0]
]}ServerList:com.alibaba.cloud.nacos.ribbon.NacosServerList@256589a1
```

将三个服务全部启动。服务提供者和服务消费者还有zuul 服务
在控制台 输入命令 curl http://localhost:9083/client/client/test
![file](https://cache.yisu.com/upload/information/20210524/347/785552.png)
我们看到打印效果，请求通过网关服务成功转发到了我们的下游服务上。并返回


- ribbon-isolation-strategy
- ignored-services
- sensitiveHeaders