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 routes = synchronizedMap(new LinkedHashMap());
    @Override
    public Mono save(Mono route){}
    @Override
    public Mono delete(Mono routeId){}

    @Override
    public Flux 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？

1. spring cloud gateway 基于webflux 背压，暂时不支持mysql 数据库
2. 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

1. 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
 * 

 * 动态路由处理类
 */
@Slf4j
@AllArgsConstructor
@Service("sysRouteConfService")
public class SysRouteConfServiceImpl extends ServiceImpl implements SysRouteConfService {
    private final RedisTemplate redisTemplate;
    private final ApplicationEventPublisher applicationEventPublisher;

    /**
     * 获取全部路由
     * 

     * RedisRouteDefinitionWriter.java
     * PropertiesRouteDefinitionLocator.java
     *
     * @return
     */
    @Override
    public List 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 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 routeDefinitionVoList = new ArrayList<>();
        routes.forEach(value -> {
            log.info("更新路由 ->{}", value);
            RouteDefinitionVo vo = new RouteDefinitionVo();
            Map 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 predicateDefinitionList =
                    predicatesArray.toList(PredicateDefinition.class);
                vo.setPredicates(predicateDefinitionList);
            }

            Object filters = map.get("filters");
            if (filters != null) {
                JSONArray filtersArray = (JSONArray) filters;
                List 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 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();
    }
}

1. 网关自定义RedisRouteDefinitionRepository

     @Slf4j
     @Component
     @AllArgsConstructor
     public class RedisRouteDefinitionWriter implements RouteDefinitionRepository {
         private final RedisTemplate redisTemplate;
     
         @Override
         public Mono save(Mono 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 delete(Mono 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 getRouteDefinitions() {
             redisTemplate.setHashValueSerializer(new Jackson2JsonRedisSerializer<>(RouteDefinitionVo.class));
             List values = redisTemplate.opsForHash().values(CommonConstant.ROUTE_KEY);
             List 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