详解Spring Cloud Gateway 数据库存储路由信息的扩展方案

动态路由背景

​ 无论你在使用Zuul还是Spring Cloud Gateway 的时候，官方文档提供的方案总是基于配置文件配置的方式

例如：

 # zuul 的配置形式
 routes:
  pig-auth:
   path: /auth/**
   serviceId: pig-auth
   stripPrefix: true
 # gateway 的配置形式
 routes:
 - id: pigx-auth
   uri: lb://pigx-auth
  predicates:
  - Path=/auth/**
  filters:
  - ValidateCodeGatewayFilter

配置更改需要重启服务，不能满足实际生产过程中的动态刷新、实时变更的业务需求。

​ 基于以上分析 pig已经提供了基于Zuul版本的动态路由功能，附Git 地址传送门,效果如下图可以实时配置修改刷新。

Spring Cloud Gateway 路由加载源码

1. DispatcherHandler 接管用户请求
2. RoutePredicateHandlerMapping 路由匹配
   1. 根据RouteLocator获取 RouteDefinitionLocator
   2. 返回多个RouteDefinitionLocator.getRouteDefinitions()的路由定义信息
3. FilteringWebHandler执行路由定义中的filter 最后路由到具体的业务服务中

Spring Cloud Gateway 默认动态路由实现

GatewayControllerEndpoint 基于actuate端点的默认实现，支持JVM 级别的动态路由，不能序列化存储

// 上图动态路由的信息保存的默认实现是基于内存的实现
public class InMemoryRouteDefinitionRepository implements RouteDefinitionRepository {
  private final Map<String, RouteDefinition> routes = synchronizedMap(new LinkedHashMap<String, RouteDefinition>());
  @Override
  public Mono<Void> save(Mono<RouteDefinition> route){}
  @Override
  public Mono<Void> delete(Mono<String> routeId){}

  @Override
  public Flux<RouteDefinition> getRouteDefinitions(){}
}

扩展基于Mysql + Redis存储分布式动态组件

为什么使用Mysql的同时，又要使用Redis？

• spring cloud gateway 基于webflux 背压，暂时不支持mysql 数据库
• Redis-reactive 支持 spring cloudgateway 的背压，同时还可以实现分布式，高性能

扩展思路

1. 增加一个路由管理模块，参考GatewayControllerEndpoint实现，启动时加载数据库中配置文件到Redis
2. 网关模块重写RouteDefinitionRepository，getRouteDefinitions（）取Redis中读取即可实现
3. 前端配合 json-view 类似插件，直接修改展示。

具体实现

路由管理模块核心处理逻辑，获取路由和更新路由

/**
 * @author lengleng
 * @date 2018年11月06日10:27:55
 * <p>
 * 动态路由处理类
 */
@Slf4j
@AllArgsConstructor
@Service("sysRouteConfService")
public class SysRouteConfServiceImpl extends ServiceImpl<SysRouteConfMapper, SysRouteConf> implements SysRouteConfService {
  private final RedisTemplate redisTemplate;
  private final ApplicationEventPublisher applicationEventPublisher;

  /**
   * 获取全部路由
   * <p>
   * RedisRouteDefinitionWriter.java
   * PropertiesRouteDefinitionLocator.java
   *
   * @return
   */
  @Override
  public List<SysRouteConf> routes() {
    SysRouteConf condition = new SysRouteConf();
    condition.setDelFlag(CommonConstant.STATUS_NORMAL);
    return baseMapper.selectList(new EntityWrapper<>(condition));
  }

  /**
   * 更新路由信息
   *
   * @param routes 路由信息
   * @return
   */
  @Override
  public Mono<Void> editRoutes(JSONArray routes) {
    // 清空Redis 缓存
    Boolean result = redisTemplate.delete(CommonConstant.ROUTE_KEY);
    log.info("清空网关路由 {} ", result);

    // 遍历修改的routes，保存到Redis
    List<RouteDefinitionVo> routeDefinitionVoList = new ArrayList<>();
    routes.forEach(value -> {
      log.info("更新路由 ->{}", value);
      RouteDefinitionVo vo = new RouteDefinitionVo();
      Map<String, Object> map = (Map) value;

      Object id = map.get("routeId");
      if (id != null) {
        vo.setId(String.valueOf(id));
      }

      Object predicates = map.get("predicates");
      if (predicates != null) {
        JSONArray predicatesArray = (JSONArray) predicates;
        List<PredicateDefinition> predicateDefinitionList =
          predicatesArray.toList(PredicateDefinition.class);
        vo.setPredicates(predicateDefinitionList);
      }

      Object filters = map.get("filters");
      if (filters != null) {
        JSONArray filtersArray = (JSONArray) filters;
        List<FilterDefinition> filterDefinitionList
          = filtersArray.toList(FilterDefinition.class);
        vo.setFilters(filterDefinitionList);
      }

      Object uri = map.get("uri");
      if (uri != null) {
        vo.setUri(URI.create(String.valueOf(uri)));
      }

      Object order = map.get("order");
      if (order != null) {
        vo.setOrder(Integer.parseInt(String.valueOf(order)));
      }

      redisTemplate.setHashValueSerializer(new Jackson2JsonRedisSerializer<>(RouteDefinitionVo.class));
      redisTemplate.opsForHash().put(CommonConstant.ROUTE_KEY, vo.getId(), vo);
      routeDefinitionVoList.add(vo);
    });

    // 逻辑删除全部
    SysRouteConf condition = new SysRouteConf();
    condition.setDelFlag(CommonConstant.STATUS_NORMAL);
    this.delete(new EntityWrapper<>(condition));

    //插入生效路由
    List<SysRouteConf> routeConfList = routeDefinitionVoList.stream().map(vo -> {
      SysRouteConf routeConf = new SysRouteConf();
      routeConf.setRouteId(vo.getId());
      routeConf.setFilters(JSONUtil.toJsonStr(vo.getFilters()));
      routeConf.setPredicates(JSONUtil.toJsonStr(vo.getPredicates()));
      routeConf.setOrder(vo.getOrder());
      routeConf.setUri(vo.getUri().toString());
      return routeConf;
    }).collect(Collectors.toList());
    this.insertBatch(routeConfList);
    log.debug("更新网关路由结束 ");

    this.applicationEventPublisher.publishEvent(new RefreshRoutesEvent(this));
    return Mono.empty();
  }
}

网关自定义RedisRouteDefinitionRepository

 @Slf4j
 @Component
 @AllArgsConstructor
 public class RedisRouteDefinitionWriter implements RouteDefinitionRepository {
   private final RedisTemplate redisTemplate;

   @Override
   public Mono<Void> save(Mono<RouteDefinition> route) {
     return route.flatMap(r -> {
       RouteDefinitionVo vo = new RouteDefinitionVo();
       BeanUtils.copyProperties(r, vo);
       log.info("保存路由信息{}", vo);
       redisTemplate.opsForHash().put(CommonConstant.ROUTE_KEY, r.getId(), vo);
       return Mono.empty();
     });
   }
   @Override
   public Mono<Void> delete(Mono<String> routeId) {
     routeId.subscribe(id -> {
       log.info("删除路由信息{}", id);
       redisTemplate.opsForHash().delete(CommonConstant.ROUTE_KEY, id);
     });
     return Mono.empty();
   }

   @Override
   public Flux<RouteDefinition> getRouteDefinitions() {
     redisTemplate.setHashValueSerializer(new Jackson2JsonRedisSerializer<>(RouteDefinitionVo.class));
     List<RouteDefinitionVo> values = redisTemplate.opsForHash().values(CommonConstant.ROUTE_KEY);
     List<RouteDefinition> definitionList = new ArrayList<>();
     values.forEach(vo -> {
       RouteDefinition routeDefinition = new RouteDefinition();
       BeanUtils.copyProperties(vo, routeDefinition);
       definitionList.add(vo);
     });
     log.debug("redis 中路由定义条数： {}， {}", definitionList.size(), definitionList);
     return Flux.fromIterable(definitionList);
   }
 }

3.库表定义

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