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？

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();
	}
}

2. 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