基于Nacos实现GateWay动态路由功能

SpringBoot: 2.6.5

SpringCloud: 2021.0.0

SpringCloudAlibaba: 2021.0.1.0

Nacos: 2.1.0

@Slf4j
@Component
public class MyInMemoryRouteDefinitionRepository implements RouteDefinitionRepository {

    private final Map<String, RouteDefinition> routes = Collections.synchronizedMap(new LinkedHashMap<>());

    @Override
    public Flux<RouteDefinition> getRouteDefinitions() {
        Map<String, RouteDefinition> routesSafeCopy = new LinkedHashMap(this.routes);
        return Flux.fromIterable(routesSafeCopy.values());
    }

    @Override
    public Mono<Void> save(Mono<RouteDefinition> route) {
        return route.flatMap((r) -> {
            if (ObjectUtils.isEmpty(r.getId())) {
                return Mono.error(new IllegalArgumentException("id may not be empty"));
            } else {
                this.routes.put(r.getId(), r);
                return Mono.empty();
            }
        });
    }

    @Override
    public Mono<Void> delete(Mono<String> routeId) {
        return routeId.flatMap((id) -> {
            if (this.routes.containsKey(id)) {
                this.routes.remove(id);
            } else {
                log.warn("RouteDefinition not found: " + routeId);
            }
            return Mono.empty();
        });
    }
}

@Slf4j
@Component
public class DynamicRouteUtil implements ApplicationEventPublisherAware {

    @Resource
    private MyInMemoryRouteDefinitionRepository routeDefinitionRepository;

    private ApplicationEventPublisher publisher;

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

    public void deleteRoute(String id) {
        try {
            log.info("gateway delete route id {}", id);
            this.routeDefinitionRepository.delete(Mono.just(id)).subscribe();
            this.publisher.publishEvent(new RefreshRoutesEvent(this));
        } catch (Exception e) {
            log.error("{}：删除路由失败", id);
        }
    }

    public void updateRoutes(List<RouteDefinition> definitions) {
        log.info("gateway update routes {}", definitions);
        // 获取存在路由列表
        List<RouteDefinition> routeDefinitionsExits = this.routeDefinitionRepository
                .getRouteDefinitions()
                .buffer()
                .blockFirst();

        // 删除路由
        if (CollectionUtils.isNotEmpty(routeDefinitionsExits)) {
            for (RouteDefinition routeDefinitionsExit : routeDefinitionsExits) {
                deleteRoute(routeDefinitionsExit.getId());
            }
        }
        // 更新路由
        definitions.forEach(this::updateRoute);
    }

    public void updateRoute(RouteDefinition definition) {
        // 先删
        log.info("gateway delete route {}", definition);
        this.routeDefinitionRepository.delete(Mono.just(definition.getId()));

        // 后增
        this.routeDefinitionRepository.save(Mono.just(definition)).subscribe();
        this.publisher.publishEvent(new RefreshRoutesEvent(this));
    }

    public void addRoutes(List<RouteDefinition> definitions) {
        if (CollectionUtils.isEmpty(definitions)) {
            return;
        }
        for (RouteDefinition definition : definitions) {
            log.info("add route:{}", definition.getId());
            this.routeDefinitionRepository.save(Mono.just(definition)).subscribe();
        }
        this.publisher.publishEvent(new RefreshRoutesEvent(this));
    }
}

Component
public class DynamicRouteHandle {

    @Resource
    private DynamicRouteUtil dynamicRouteUtil;

    @Resource
    private NacosConfigProperties nacosConfigProperties;

    private ConfigService configService;

    public static final String ROUTE_DATA_ID = "gateway-router.json";

    public static final long DEFAULT_TIMEOUT = 30000;

    @PostConstruct
    public void init() {
        log.info("gateway route init...");
        try {
            configService = initConfigService();
            if (configService == null) {
                log.warn("initConfigService fail");
                return;
            }

            String configInfo = configService.getConfig(ROUTE_DATA_ID, nacosConfigProperties.getGroup(), DEFAULT_TIMEOUT);
            log.info("获取网关当前配置:{}", configInfo);
            List<RouteDefinition> definitionList = JSON.parseArray(configInfo, RouteDefinition.class);
            log.info("获取网关数量：{}", definitionList.size());

            dynamicRouteUtil.addRoutes(definitionList);
        } catch (Exception e) {
            log.error("初始化网关路由时发生错误", e);
        }
        // 添加监听
        dynamicRouteByNacosListener(ROUTE_DATA_ID, nacosConfigProperties.getGroup());
    }

    public void dynamicRouteByNacosListener(String dataId, String group) {
        try {
            configService.addListener(dataId, group, new Listener() {
                @Override
                public void receiveConfigInfo(String configInfo) {
                    log.info("进行网关更新:\n\r{}", configInfo);
                    List<RouteDefinition> definitionList = JSON.parseArray(configInfo, RouteDefinition.class);
                    log.info("update route : {}", definitionList.toString());
                    dynamicRouteUtil.updateRoutes(definitionList);
                }

                @Override
                public Executor getExecutor() {
                    log.info("getExecutor\n\r");
                    return null;
                }
            });
        } catch (NacosException e) {
            log.error("从nacos接收动态路由配置出错!!!", e);
        }
    }

    private ConfigService initConfigService() {
        try {
            Properties properties = new Properties();
            properties.setProperty("serverAddr", nacosConfigProperties.getServerAddr());
            properties.setProperty("namespace", nacosConfigProperties.getNamespace());
            properties.setProperty("username", nacosConfigProperties.getUsername());
            properties.setProperty("password", nacosConfigProperties.getPassword());
            return NacosFactory.createConfigService(properties);
        } catch (Exception e) {
            log.error("初始化网关路由时发生错误", e);
            return null;
        }
    }
}

gateway-router.json

[{
  "id": "user-route",
  "order": 0,
  "predicates": [{
    "name": "Path",
    "args": {
      "_genkey_0": "/userApp/**"
    }
  }],
  "filters": [],
  "uri": "lb://user"
},{
  "id": "product-route",
  "order": 0,
  "predicates": [{
    "name": "Path",
    "args": {
      "_genkey_0": "/productApp/**"
    }
  }],
  "filters": [],
  "uri": "lb://product"
}]

注: 如果服务设置了context-path并且与服务名称相同会有问题, 详情: https://blog.csdn.net/weixin_43303455/article/details/122279447, GatewayDiscoveryClientAutoConfiguration.java会为每一个服务创建一个默认路由, 此路由有一个RewritePathGatewayFilter, 会将context-path与serviceId(服务名称)相同的进行置空。

注: 通过 网关服务:ip/actuator/gateway/routes, 可以查看具体的路由信息, 前提是要开启配置

management:
  endpoints:
    web:
      exposure:
        include: '*'
  endpoint:
    health:
      show-details: always