一、说明
网关的核心概念就是路由配置和路由规则,而作为所有请求流量的入口,在实际生产环境中为了保证高可靠和高可用,是尽量要避免重启的,所以实现动态路由是非常有必要的;本文主要介绍实现的思路,并且以Nacos
为数据源来讲解
二、实现要点
要实现动态路由只需关注下面4个点
- 网关启动时,
动态路由
的数据怎样加载进来
静态路由
与动态路由
以那个为准,ps:静态路由
指的是配置文件里写死的路由配置
- 监听
动态路由
的数据源变化
- 数据有变化时怎样
通知zuul
刷新路由
三、具体实现
3.1. 实现动态路由的数据加载
- 重写
SimpleRouteLocator
类的locateRoutes
方法,此方法是加载路由配置的,父类中是获取properties中的路由配置,可以通过扩展此方法,达到动态获取配置的目的
- 这里采用
静态路由
与动态路由
共存,相同路由id以动态路由
优先覆盖的实现方式
AbstractDynRouteLocator类可查看:AbstractDynRouteLocator.java
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| public abstract class AbstractDynRouteLocator extends SimpleRouteLocator implements RefreshableRouteLocator { private ZuulProperties properties;
public AbstractDynRouteLocator(String servletPath, ZuulProperties properties) { super(servletPath, properties); this.properties = properties; }
@Override public void refresh() { doRefresh(); }
@Override protected Map<String, ZuulRoute> locateRoutes() { LinkedHashMap<String, ZuulRoute> routesMap = new LinkedHashMap<>(); routesMap.putAll(super.locateRoutes()); routesMap.putAll(loadDynamicRoute()); LinkedHashMap<String, ZuulRoute> values = new LinkedHashMap<>(); for (Map.Entry<String, ZuulRoute> entry : routesMap.entrySet()) { String path = entry.getKey(); if (!path.startsWith("/")) { path = "/" + path; } if (StringUtils.hasText(this.properties.getPrefix())) { path = this.properties.getPrefix() + path; if (!path.startsWith("/")) { path = "/" + path; } } values.put(path, entry.getValue()); } return values; }
public abstract Map<String, ZuulRoute> loadDynamicRoute(); }
|
由于动态路由的数据可以有很多种途径,如:Nacos、Redis、Zookeeper、DB等,所以这里定义一个抽象类,由具体的实现类去定义loadDynamicRoute
方法
3.2. Nacos路由实现类
NacosDynRouteLocator类完整的代码实现可查看:NacosDynRouteLocator.java
3.2.1. 实现loadDynamicRoute
方法获取动态数据
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| @Override public Map<String, ZuulProperties.ZuulRoute> loadDynamicRoute() { Map<String, ZuulRoute> routes = new LinkedHashMap<>(); if (zuulRouteEntities == null) { zuulRouteEntities = getNacosConfig(); } for (ZuulRouteEntity result : zuulRouteEntities) { if (StrUtil.isBlank(result.getPath()) || !result.isEnabled()) { continue; } ZuulRoute zuulRoute = new ZuulRoute(); BeanUtil.copyProperties(result, zuulRoute); routes.put(zuulRoute.getPath(), zuulRoute); } return routes; } private List<ZuulRouteEntity> getNacosConfig() { try { String content = nacosConfigProperties.configServiceInstance().getConfig(ZUUL_DATA_ID, ZUUL_GROUP_ID,5000); return getListByStr(content); } catch (NacosException e) { log.error("listenerNacos-error", e); } return new ArrayList<>(0); }
|
3.2.2. 增加NacosListener
监听路由数据变化
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| private void addListener() { try { nacosConfigProperties.configServiceInstance().addListener(ZUUL_DATA_ID, ZUUL_GROUP_ID, new Listener() { @Override public Executor getExecutor() { return null; }
@Override public void receiveConfigInfo(String configInfo) { locator.setZuulRouteEntities(getListByStr(configInfo)); RoutesRefreshedEvent routesRefreshedEvent = new RoutesRefreshedEvent(locator); publisher.publishEvent(routesRefreshedEvent); } }); } catch (NacosException e) { log.error("nacos-addListener-error", e); } }
|
注意路由数据变化后不需要自己手动刷新路由,只需要给zuul
发送一个RoutesRefreshedEvent
事件即可,zuul
自己有个ZuulRefreshListener类
会监听事件帮我们刷新路由
3.3. 配置类创建NacosDynRouteLocator
的Bean
DynamicZuulRouteConfig可查看:NacosDynRouteLocator.java
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| @Configuration @ConditionalOnProperty(prefix = "zlt.gateway.dynamicRoute", name = "enabled", havingValue = "true") public class DynamicZuulRouteConfig { @Autowired private ZuulProperties zuulProperties;
@Autowired private DispatcherServletPath dispatcherServletPath;
@Configuration @ConditionalOnProperty(prefix = "zlt.gateway.dynamicRoute", name = "dataType", havingValue = "nacos", matchIfMissing = true) public class NacosZuulRoute { @Autowired private NacosConfigProperties nacosConfigProperties;
@Autowired private ApplicationEventPublisher publisher;
@Bean public NacosDynRouteLocator nacosDynRouteLocator() { return new NacosDynRouteLocator(nacosConfigProperties, publisher, dispatcherServletPath.getPrefix(), zuulProperties); } } }
|
这里通过自定义配置来控制是否开启动态路由功能
3.4. 添加Nacos
路由配置
新增配置项:
- Data Id:zuul-routes
- Group:ZUUL_GATEWAY
- 配置内容:
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| [ { "enabled":true, "id":"csdn", "path":"/csdn/**", "retryable":false, "stripPrefix":true, "url":"https://www.csdn.net/" }, { "enabled":true, "id":"github", "path":"/github/**", "retryable":false, "stripPrefix":true, "url":"http://github.com/" } ]
|
添加两条路由数据
四、测试
- 启动网关通过
/actuator/routes
端点查看当前路由信息
可以看到静态路由和Nacos
里配置的两条路由信息并存显示
- 修改
Nacos
配置,关闭csdn
路由
- 刷新查看网关的路由信息
csdn
的路由已经看不到了,实现了动态改变路由配置