Spring Cloud Gateway 數據庫存儲路由信息的擴展方案

動態路由背景

​ 不管你在使用Zuul仍是Spring Cloud Gateway 的時候，官方文檔提供的方案老是基於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

配置更改須要重啓服務，不能知足實際生產過程當中的動態刷新、實時變動的業務需求。

​ 基於以上分析 pig已經提供了基於Zuul版本的動態路由功能，附Git 地址傳送門,效果以下圖能夠實時配置修改刷新。

Spring Cloud Gateway 路由加載源碼

1. DispatcherHandler 接管用戶請求
2. RoutePredicateHandlerMapping 路由匹配
   1. 根據RouteLocator獲取 RouteDefinitionLocator
   2. 返回多個RouteDefinitionLocator.getRouteDefinitions()的路由定義信息
3. FilteringWebHandler執行路由定義中的filter 最後路由到具體的業務服務中

Spring Cloud Gateway 默認動態路由實現

GatewayControllerEndpoint 基於actuate端點的默認實現，支持JVM 級別的動態路由，不能序列化存儲

// 上圖動態路由的信息保存的默認實現是基於內存的實現
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(){}
}

擴展基於Mysql + Redis存儲分佈式動態組件

爲何使用Mysql的同時，又要使用Redis？

1. spring cloud gateway 基於webflux 背壓，暫時不支持mysql 數據庫
2. redis-reactive 支持 spring cloud gateway 的背壓，同時還能夠實現分佈式，高性能

擴展思路

1. 增長一個路由管理模塊，參考GatewayControllerEndpoint實現，啓動時加載數據庫中配置文件到Redis
2. 網關模塊重寫RouteDefinitionRepository，getRouteDefinitions（）取Redis中讀取便可實現
3. 前端配合 json-view 相似插件，直接修改展現。

具體實現

1. 路由管理模塊核心處理邏輯，獲取路由和更新路由

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

	/**
	 * 獲取所有路由
	 * <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 緩存
		Boolean result = redisTemplate.delete(CommonConstant.ROUTE_KEY);
		log.info("清空網關路由 {} ", result);

		// 遍歷修改的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);
		});

		// 邏輯刪除所有
		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("更新網關路由結束 ");

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

2. 網關自定義RedisRouteDefinitionRepository

   /**
    * @author lengleng
    * @date 2018/10/31
    * <p>
    * redis 保存路由信息，優先級比配置文件高
    */
   @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("刪除路由信息{}", id);
   			redisTemplate.opsForHash().delete(CommonConstant.ROUTE_KEY, id);
   		});
   		return Mono.empty();
   	}
   
   	/**
   	 * 動態路由入口
   	 *
   	 * @return
   	 */
   	@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 中路由定義條數： {}， {}", definitionList.size(), definitionList);
   		return Flux.fromIterable(definitionList);
   	}
   }

3.庫表定義