spring cloud zuul 实现动态路由

前期工作

服务提供者的eureka添加配置

# 配置 server.servlet.context-path                必须配置,不可单独为反斜杠 /
server.servlet.context-path=/user/
# 在eurek的metadata-map 中存入 server.servlet.context-path
eureka.instance.metadata-map.context-path=${server.servlet.context-path} 

改造zuul 自定义网关路由规则

package cn.zhangfusheng.zuul.server.config;

import com.netflix.appinfo.InstanceInfo;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.web.ServerProperties;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.cloud.netflix.eureka.EurekaServiceInstance;
import org.springframework.cloud.netflix.zuul.filters.Route;
import org.springframework.cloud.netflix.zuul.filters.SimpleRouteLocator;
import org.springframework.cloud.netflix.zuul.filters.ZuulProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

/**
 * @author fusheng.zhang
 * @Description 网关动态路由
 * @create 2020-04-17 20:04:00
 */
@Slf4j
@Configuration
public class ZuulRoutesConfig {

    /**
     * 注入 discoveryClient 用于获取注册中心的服务提供者列表
     */
    @Autowired
    private DiscoveryClient discoveryClient;
    @Autowired
    ZuulProperties zuulProperties;
    @Autowired
    ServerProperties serverProperties;

    @Bean
    public DynamicRoutes dynamicRoutes() {
        return new DynamicRoutes(this.serverProperties.getServlet().getContextPath(), this.zuulProperties);
    }

    /**
     * 动态路由
     * 路由规则: /${eureka.instance.metadata-map.context-path}/2020-04-20/**
     * 目的: 路由一天一变化__未测试
     */
    class DynamicRoutes extends SimpleRouteLocator {

        public DynamicRoutes(String servletPath, ZuulProperties properties) {
            super(servletPath, properties);
        }

        /**
         * 重写 SimpleRouteLocator.locateRoutes()方法
         * 自定义路由生成方式
         * @return
         */
        @Override
        protected Map<String, ZuulProperties.ZuulRoute> locateRoutes() {
            Map<String, ZuulProperties.ZuulRoute> routes = new LinkedHashMap<>();
            // 获取服务名称列表[serviceId]
            discoveryClient.getServices().forEach(serviceId -> {
                // 获取服务名称对应的实例
                discoveryClient.getInstances(serviceId).forEach(instance -> {
                    InstanceInfo instanceInfo = ((EurekaServiceInstance) instance).getInstanceInfo();
                    // 从 eureka.instance.metadata-map中获取context-path,既服务提供者的server.servlet.context-path
                    // 如果获取不到,则采用服务名称'-'切割的方式作为路由
                    String key = instanceInfo.getMetadata().getOrDefault(
                            "context-path", String.format("/%s/", instanceInfo.getSecureVipAddress().split("-")[0]));
                    // 今天的日期
                    String localDate = LocalDate.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd"));
                    // 生成 /${eureka.instance.metadata-map.context-path}/2020-04-20/** 格式的key
                    key = String.format("%s%s/**", key, localDate);
                    ZuulProperties.ZuulRoute zuulRoute = new ZuulProperties.ZuulRoute();
                    zuulRoute.setLocation(instanceInfo.getSecureVipAddress());
                    zuulRoute.setId(instanceInfo.getSecureVipAddress());
                    zuulRoute.setPath(key);
                    zuulRoute.setServiceId(instanceInfo.getSecureVipAddress());
                    routes.put(key, zuulRoute);
                });
            });
            return routes;
        }

        @Override
        public List<Route> getRoutes() {
            List<Route> values = new ArrayList<>();
            for (Map.Entry<String, ZuulProperties.ZuulRoute> entry : locateRoutes().entrySet()) {
                values.add(getRoute(entry.getValue(), entry.getValue().getPath()));
            }
            return values;
        }
    }
}