Spring Cloud Alibaba实战(七) - Gateway搭配Nacos实现动态路由

目录

(一)Nacos动态配置
(二)Nacos注册中心
(三)Sentinel之限流
(四)Sentinel之熔断
(五)Gateway之路由、限流
(六)Gateway之鉴权、日志
(七)Gateway搭配Nacos实现动态路由
(八)Dubbo + Nacos

正文

在 Spring Cloud Alibaba实战(五) - Gateway之路由、限流​ 中，路由信息定义在配置文件中，这种方式有一个缺点就是修改路由信息必须重启服务才能生效。网关作为全部流量的入口，可用时间当然越长越好，不重启服务而修改路由是一个更好的选择，结合Nacos可以做到这一点。

首先，参考前面章节启动Nacos、account-service和payment-service。并以gateway项目为基础增加本节功能。

Spring Cloud Gateway本身还不支持直接从Nacos动态加载路由配置表，需要自己编写监听器监听配置变化并刷新路由表。

NacosDynamicRouteService.java

@Component
public class NacosDynamicRouteService implements ApplicationEventPublisherAware {

    private String dataId = "gateway-router";

    private String group = "DEFAULT_GROUP";

    @Value("${spring.cloud.nacos.config.server-addr}")
    private String serverAddr;

    @Autowired
    private RouteDefinitionWriter routeDefinitionWriter;

    private ApplicationEventPublisher applicationEventPublisher;

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

    @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 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;
    }
}

代码中监听的配置ID为gateway-router，按此ID在Nacos中创建配置

 

从bootstrap.yml中删除路由配置，即删除以下内容

      routes:
      - id: payment-router
        uri: lb://payment-service
        predicates:
        - Path=/pay/**
        filters:
        - name: RequestRateLimiter
          args:
            redis-rate-limiter.replenishRate: 1
            redis-rate-limiter.burstCapacity: 5
            key-resolver: '#{@ipKeyResolver}'

动态路由功能修改完成，启动gateway测试，目前路由表中仅匹配了/acc/**的，分别测试一下/acc和/pay。 

 

/acc/user请求成功转发到account-service，而/pay/balance没有找到匹配的路由信息，与期望行为一致。

下面来动态增加/pay的路由，修改Nacos中的gateway-router配置如下：

[{
    "id": "account-router",
    "order": 0,
    "predicates": [{
        "args": {
            "pattern": "/acc/**"
        },
        "name": "Path"
    }],
    "uri": "lb://account-service"
},{
    "id": "payment-router",
    "order": 2,
    "predicates": [{
        "args": {
            "pattern": "/pay/**"
        },
        "name": "Path"
    }],
    "uri": "lb://payment-service"
}]

不重启gateway再次测试/pay/balance请求 

 

可以看到新增加的路由配置已生效。

本期代码 

链接：https://pan.baidu.com/s/1ANe7slFiUw0nm1HBXdzzFg
提取码：2was