Gateway基于Nacos动态路由实现_gateway结合nacos动态路由-优快云博客

一、查看SringCloud Gateway 官方文档，Gateway 工作原理如下图：

客户端请求，首先会被Gateway Handler Mapping处理，用以在 路由表 中查找一个与请求匹配的 路由，然后将请求交由 Web Handler 处理，Web Handler 维护了一个过滤器链，链式执行这些过滤器，这些过滤器在逻辑上存在两个执行阶段 pre 与 post

二、Nacos官方简介

Nacos 致力于帮助您发现、配置和管理微服务。Nacos 提供了一组简单易用的特性集，帮助您快速实现动态服务发现、服务配置、服务元数据及流量管理。Nacos 帮助您更敏捷和容易地构建、交付和管理微服务平台。Nacos 是构建以“服务”为中心的现代应用架构 (例如微服务范式、云原生范式) 的服务基础设施。主要特性如下：

1. 服务发现和服务健康监测
2. 动态配置服务
3. 动态 DNS 服务
4. 服务及其元数据管理

三、实现思路

四、代码

1、依赖

 <!--gateway-->
 <dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-gateway</artifactId>
    <version>2.2.6.RELEASE</version>
 </dependency>
 <!--负载均衡-->
 <dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-loadbalancer</artifactId>
 </dependency>
 <!--nacos-->
 <dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    <version>0.2.2.RELEASE</version>
 </dependency>
 <dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
 </dependency>

2、yml配置

server:
  port: 8001
spring:
  application:
    name: springcloud-alibaba-gateway
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
    #网关配置
    gateway:
      discovery:
        locator:
          #服务名小写
          lower-case-service-id: true

####################
##nacos动态路由配置格式##
#[{
#   "id":  "b-service-user",
#   "uri": "lb://b-service-user", # lb协议表示启用负载均衡功能，然后后面跟着微服务名称
#   "predicates": [{
#                    "name": "Path",
#                    "args": {
#                        "pattern":"/user/**"
#                    }
#                  }],
#   "filters": [{
#                 "name":  "StripPrefix",
#                 "args":  {
#                        "pattern": 1
#                 }
#               }]
# }]

# 配置
config:
  # 动态
  dynamic-route:
    # nacos 配置dataId
    dataId: gateway-routes
    # 分组
    group: GATEWAY_GROUP
    # nacos服务地址
    server-addr: 127.0.0.1:8848

3、NacosDynamicRouteService

package com.llj.config;

import com.alibaba.fastjson.JSONObject;
import com.alibaba.nacos.api.NacosFactory;
import com.alibaba.nacos.api.config.ConfigService;
import com.alibaba.nacos.api.config.listener.Listener;
import com.alibaba.nacos.api.exception.NacosException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.gateway.event.RefreshRoutesEvent;
import org.springframework.cloud.gateway.route.RouteDefinition;
import org.springframework.cloud.gateway.route.RouteDefinitionWriter;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.ApplicationEventPublisherAware;
import org.springframework.stereotype.Component;
import reactor.core.publisher.Mono;

import javax.annotation.PostConstruct;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Executor;

/**
 * @PakcageName:com.llj.config
 * @ClassName:NacosDynamicRouteService
 * @Description: 监听nacos配置
 * @Author:liulianjia
 * @Date:2022/9/20 23:04
 */
@Component
public class NacosDynamicRouteService implements ApplicationEventPublisherAware {
    @Value("${config.dynamic-route.dataId}")
    private String dataId;

    @Value("${config.dynamic-route.group}")
    private String group;

    @Value("${config.dynamic-route.server-addr}")
    private String serverAddr;

    @Autowired
    private RouteDefinitionWriter routeDefinitionWriter;

    private ApplicationEventPublisher applicationEventPublisher;

    private static final List<String> ROUTE_LIST = new ArrayList<>(16);

    @PostConstruct
    public void dynamicRouteByNacosListener() {
        try {
            ConfigService configService = NacosFactory.createConfigService(serverAddr);
            configService.getConfig(dataId, group, 5000);
            configService.addListener(dataId, group, new Listener() {
                @Override
                public void receiveConfigInfo(String configInfo) {
                    clearRoute();
                    try {
                        List<RouteDefinition> gatewayRouteDefinitions = JSONObject.parseArray(configInfo, RouteDefinition.class);
                        for (RouteDefinition routeDefinition : gatewayRouteDefinitions) {
                            addRoute(routeDefinition);
                        }
                        publish();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }

                @Override
                public Executor getExecutor() {
                    return null;
                }
            });
        } catch (NacosException e) {
            e.printStackTrace();
        }
    }

    private void clearRoute() {
        for (String id : ROUTE_LIST) {
            this.routeDefinitionWriter.delete(Mono.just(id)).subscribe();
        }
        ROUTE_LIST.clear();
    }

    private void addRoute(RouteDefinition definition) {
        try {
            routeDefinitionWriter.save(Mono.just(definition)).subscribe();
            ROUTE_LIST.add(definition.getId());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void publish() {
        this.applicationEventPublisher.publishEvent(new RefreshRoutesEvent(this.routeDefinitionWriter));
    }

    @Override
    public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
        this.applicationEventPublisher = applicationEventPublisher;
    }
}

4、启动类

package com.llj;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

/**
 * @PakcageName:com.llj
 * @ClassName:GatewayApplication
 * @Description:
 * @Author:liulianjia
 * @Date:2022/9/20 22:40
 */
@SpringBootApplication
@EnableDiscoveryClient
public class GatewayApplication {
    public static void main(String[] args) {
        SpringApplication.run(GatewayApplication.class, args);
        System.out.println("----- 服务网关启动 -----");
    }
}

5、测试，Nacos添加路由配置，注意"Data ID" 和 “Group”要和配置一一对应