前言
Nacos最近项目一直在使用，其简单灵活，支持更细粒度的命令空间，分组等为麻烦复杂的环境切换提供了方便；同时也很好支持动态路由的配置，只需要简单的几步即可。在国产的注册中心、配置中心中比较突出，容易上手，本文通过gateway、nacos-consumer、nacos-provider三个简单模块来展示：Nacos下动态路由配置。
一、Nacos环境准备
1、启动Nacos配置中心并创建路由配置
具体的Nacos怎么配置就不介绍了，可以参考阿里巴巴的官方介绍，这里通过windows直接本地启动开启单机模式，登录Nacos Console，创建dev的namespace，在dev下的默认分组下创建gateway-router的dataId
gateway-router的主要初始化配置如下：关于gateway的组成（id，order、predicates断言，uri）这里就不详细说明的了，可以自行百度下
[{
"id": "consumer-router",
"order": 0,
"predicates": [{
"args": {
"pattern": "/consume/**"
},
"name": "Path"
}],
"uri": "lb://nacos-consumer"
},{
"id": "provider-router",
"order": 2,
"predicates": [{
"args": {
"pattern": "/provide/**"
},
"name": "Path"
}],
"uri": "lb://nacos-provider"
}]
2、连接Nacos配置中心
通常在项目中配置“配置中心”往往都是在bootstrap.propertis(yaml)中配置，这样才能保证项目中路由配置从Nacos Config中读取。
# nacos配置中心配置建议在bootstrap.properties中配置
spring.cloud.nacos.config.server-addr=127.0.0.1:8848
#spring.cloud.nacos.config.file-extension=properties
# 配置中心的命名空间：dev 的命名空间（环境）
spring.cloud.nacos.config.namespace=08ecd1e5-c042-410a-84d5-b0a8fbeed8ea
Application启动类中增加注解@EnableDiscoveryClient，才能保证连接到Nacos Config
@SpringBootApplication @EnableDiscoveryClient public class GatewayApplication { public static void main( String[] args ) { SpringApplication.run(GatewayApplication.class, args); } }
二、项目构建
1、项目结构
创建简单的spring boot多模块结构，推荐使用idea创建
1）Nacos父模块：
<groupId>com.springcloud</groupId>
<artifactId>nacos</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>nacos</name>
<description>Nacos Demo</description>
首先pom文件引入Spring Cloud Alibaba Nacos组件：注册中心nacos-discovery与配置中心nacos-config
<!--nacos 客户端 注册中心-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
<version>${alibaba-nacos.version}</version>
</dependency>
<!--nacos 客户端 配置中心-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
<version>${alibaba-nacos.version}</version>
</dependency>
其次再引入Spring Cloud相关组件依赖
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>${spring-boot.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
其它组件依赖引入（修正：如果引入了nacos-api相关的JSON依赖，那么fastjson就不需要再引入了，否则可能冲突）：
<dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>${fastjson.version}</version> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>${lombok.version}</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>${slf4j.version}</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId> </dependency>
注意，这里有个坑，spring cloud gateway使用的web框架为webflux，和springMVC不兼容。所以不要引入（修正：只有gateway服务不用引入springMVC，其他需要引入）
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency>
2）三个子模块：gateway、nacos-consumer、nacos-provider
<modules>
<module>nacos-provider</module>
<module>nacos-consumer</module>
<module>gateway</module>
</modules>
结构截图如下所示：
3）三个服务的端口分别为：
nacos-consume:6001
nacos-provider:6002
gateway：6003
4）服务架构如下：
2、编写测试代码
（1）在gateway模块中主要实现以下功能：
第一，从Nacos配置中心中加载动态路由的相关配置，就需要读取Nacos的命名空间namespace，通过dataId获取配置
/** * 路由类配置 */ @Configuration public class GatewayConfig { public static final long DEFAULT_TIMEOUT = 30000; public static String NACOS_SERVER_ADDR; public static String NACOS_NAMESPACE; public static String NACOS_ROUTE_DATA_ID; public static String NACOS_ROUTE_GROUP; @Value("${spring.cloud.nacos.discovery.server-addr}") public void setNacosServerAddr(String nacosServerAddr){ NACOS_SERVER_ADDR = nacosServerAddr; } @Value("${spring.cloud.nacos.discovery.namespace}") public void setNacosNamespace(String nacosNamespace){ NACOS_NAMESPACE = nacosNamespace; } @Value("${nacos.gateway.route.config.data-id}") public void setNacosRouteDataId(String nacosRouteDataId){ NACOS_ROUTE_DATA_ID = nacosRouteDataId; } @Value("${nacos.gateway.route.config.group}") public void setNacosRouteGroup(String nacosRouteGroup){ NACOS_ROUTE_GROUP = nacosRouteGroup; } }
properties配置关于Nacos下读取gateway-router的配置：
spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848 spring.cloud.nacos.discovery.namespace=08ecd1e5-c042-410a-84d5-b0a8fbeed8ea nacos.gateway.route.config.data-id=gateway-router nacos.gateway.route.config.group=DEFAULT_GROUP
第二，初始化路由，监听动态路由配置的数据源变化；
/** * * 通过nacos下发动态路由配置,监听Nacos中gateway-route配置 * */ @Component @Slf4j @DependsOn({"gatewayConfig"}) // 依赖于gatewayConfig bean public class DynamicRouteServiceImplByNacos { @Autowired private DynamicRouteServiceImpl dynamicRouteService; private ConfigService configService; @PostConstruct public void init() { log.info("gateway route init..."); try{ configService = initConfigService(); if(configService == null){ log.warn("initConfigService fail"); return; } String configInfo = configService.getConfig(GatewayConfig.NACOS_ROUTE_DATA_ID, GatewayConfig.NACOS_ROUTE_GROUP, GatewayConfig.DEFAULT_TIMEOUT); log.info("获取网关当前配置: {}",configInfo); List<RouteDefinition> definitionList = JSON.parseArray(configInfo, RouteDefinition.class); for(RouteDefinition definition : definitionList){ log.info("update route : {}",definition.toString()); dynamicRouteService.add(definition); } } catch (Exception e) { log.error("初始化网关路由时发生错误",e); } dynamicRouteByNacosListener(GatewayConfig.NACOS_ROUTE_DATA_ID,GatewayConfig.NACOS_ROUTE_GROUP); } /** * 监听Nacos下发的动态路由配置 * @param dataId * @param group */ public void dynamicRouteByNacosListener (String dataId, String group){ try { configService.addListener(dataId, group, new Listener() { @Override public void receiveConfigInfo(String configInfo) { log.info("进行网关更新: {}",configInfo); List<RouteDefinition> definitionList = JSON.parseArray(configInfo, RouteDefinition.class); for(RouteDefinition definition : definitionList){ log.info("update route : {}",definition.toString()); dynamicRouteService.update(definition); } } @Override public Executor getExecutor() { log.info("getExecutor "); return null; } }); } catch (NacosException e) { log.error("从nacos接收动态路由配置出错!!!",e); } } /** * 初始化网关路由 nacos config * @return */ private ConfigService initConfigService(){ try{ Properties properties = new Properties(); properties.setProperty("serverAddr",GatewayConfig.NACOS_SERVER_ADDR); properties.setProperty("namespace",GatewayConfig.NACOS_NAMESPACE); return configService= NacosFactory.createConfigService(properties); } catch (Exception e) { log.error("初始化网关路由时发生错误",e); return null; } } }
第三，刷新最新的动态路由变化，实现动态增删改路由
/** * 动态更新路由网关service * 1）实现一个Spring提供的事件推送接口ApplicationEventPublisherAware * 2）提供动态路由的基础方法，可通过获取bean操作该类的方法。该类提供新增路由、更新路由、删除路由，然后实现发布的功能。 */ @Slf4j @Service public class DynamicRouteServiceImpl implements ApplicationEventPublisherAware { @Autowired private RouteDefinitionWriter routeDefinitionWriter; /** * 发布事件 */ @Autowired private ApplicationEventPublisher publisher; @Override public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) { this.publisher = applicationEventPublisher; } /** * 删除路由 * @param id * @return */ public String delete(String id) { try { log.info("gateway delete route id {}",id); this.routeDefinitionWriter.delete(Mono.just(id)); return "delete success"; } catch (Exception e) { return "delete fail"; } } /** * 更新路由 * @param definition * @return */ public String update(RouteDefinition definition) { try { log.info("gateway update route {}",definition); this.routeDefinitionWriter.delete(Mono.just(definition.getId())); } catch (Exception e) { return "update fail,not find route routeId: "+definition.getId(); } try { routeDefinitionWriter.save(Mono.just(definition)).subscribe(); this.publisher.publishEvent(new RefreshRoutesEvent(this)); return "success"; } catch (Exception e) { return "update route fail"; } } /** * 增加路由 * @param definition * @return */ public String add(RouteDefinition definition) { log.info("gateway add route {}",definition); routeDefinitionWriter.save(Mono.just(definition)).subscribe(); this.publisher.publishEvent(new RefreshRoutesEvent(this)); return "success"; } }
（2）在consumer创建ConsumeController：通过访问gateway网关/consume/sayHello/{name}（"pattern": "/consume/**"）,跳转至nacos-consumer服务（"uri": "lb://nacos-consumer"），
@RequestMapping("/consume/")
@Slf4j
public class ConsumeController {
@GetMapping("/sayHello/{name}")
public String sayHello(@PathVariable("name") String name){
log.info("I'm calling nacos-consumer service by dynamic gateway...");
return name + " Hi~, I'm from nacos-consumer";
}
}
（3）在provider创建ProviderController：通过访问gateway网关/provide/sayHello/{name}（"pattern": "/provide/**"）,跳转至nacos-provider服务（"uri": "lb://nacos-provider"）
@RestController @RequestMapping("/provide/") @Slf4j public class ProviderController { @GetMapping("/sayHello/{name}") public String sayHello(@PathVariable("name") String name){ log.info("I'm calling nacos-provider service by dynamic gateway..."); return name + " Hi~, I'm from nacos-provider"; } }
三、测试动态网关配置
1、启动服务，观察注册中心
分别启动gateway、nacos-consumer、nacos-provider三个服务，观察是否已经在Nacos上正确注册
注意：需要指定注册中心的namespace为dev的空间，即spring.cloud.nacos.discovery.namespace=08ecd1e5-c042-410a-84d5-b0a8fbeed8ea
2、访问网关，观察服务日志
（1）查看gateway服务的初始化启动日志：会发现可以正常从Nacos获取配置gateway-router网关配置文件内容，并进行正确路由加载...
2020-05-10 14:33:44.557 INFO 1272 --- [ main] c.g.r.DynamicRouteServiceImplByNacos : gateway route init... 2020-05-10 14:33:44.578 INFO 1272 --- [ main] c.g.r.DynamicRouteServiceImplByNacos : 获取网关当前配置: [{ "id": "consumer-router", "order": 0, "predicates": [{ "args": { "pattern": "/consume/**" }, "name": "Path" }], "uri": "lb://nacos-consumer" },{ "id": "provider-router", "order": 2, "predicates": [{ "args": { "pattern": "/provide/**" }, "name": "Path" }], "uri": "lb://nacos-provider" }] 2020-05-10 14:33:44.691 INFO 1272 --- [ main] c.g.r.DynamicRouteServiceImplByNacos : update route : RouteDefinition{id='consumer-router', predicates=[PredicateDefinition{name='Path', args={pattern=/consume/**}}], filters=[], uri=lb://nacos-consumer, order=0, metadata={}} 2020-05-10 14:33:44.691 INFO 1272 --- [ main] c.g.service.DynamicRouteServiceImpl : gateway add route RouteDefinition{id='consumer-router', predicates=[PredicateDefinition{name='Path', args={pattern=/consume/**}}], filters=[], uri=lb://nacos-consumer, order=0, metadata={}} 2020-05-10 14:33:45.192 INFO 1272 --- [ main] o.s.c.g.r.RouteDefinitionRouteLocator : Loaded RoutePredicateFactory [After] 2020-05-10 14:33:45.192 INFO 1272 --- [ main] o.s.c.g.r.RouteDefinitionRouteLocator : Loaded RoutePredicateFactory [Before] 2020-05-10 14:33:45.192 INFO 1272 --- [ main] o.s.c.g.r.RouteDefinitionRouteLocator : Loaded RoutePredicateFactory [Between] 2020-05-10 14:33:45.193 INFO 1272 --- [ main] o.s.c.g.r.RouteDefinitionRouteLocator : Loaded RoutePredicateFactory [Cookie] 2020-05-10 14:33:45.193 INFO 1272 --- [ main] o.s.c.g.r.RouteDefinitionRouteLocator : Loaded RoutePredicateFactory [Header] 2020-05-10 14:33:45.193 INFO 1272 --- [ main] o.s.c.g.r.RouteDefinitionRouteLocator : Loaded RoutePredicateFactory [Host] 2020-05-10 14:33:45.194 INFO 1272 --- [ main] o.s.c.g.r.RouteDefinitionRouteLocator : Loaded RoutePredicateFactory [Method] 2020-05-10 14:33:45.194 INFO 1272 --- [ main] o.s.c.g.r.RouteDefinitionRouteLocator : Loaded RoutePredicateFactory [Path] 2020-05-10 14:33:45.194 INFO 1272 --- [ main] o.s.c.g.r.RouteDefinitionRouteLocator : Loaded RoutePredicateFactory [Query] 2020-05-10 14:33:45.194 INFO 1272 --- [ main] o.s.c.g.r.RouteDefinitionRouteLocator : Loaded RoutePredicateFactory [ReadBodyPredicateFactory] 2020-05-10 14:33:45.194 INFO 1272 --- [ main] o.s.c.g.r.RouteDefinitionRouteLocator : Loaded RoutePredicateFactory [RemoteAddr] 2020-05-10 14:33:45.194 INFO 1272 --- [ main] o.s.c.g.r.RouteDefinitionRouteLocator : Loaded RoutePredicateFactory [Weight] 2020-05-10 14:33:45.194 INFO 1272 --- [ main] o.s.c.g.r.RouteDefinitionRouteLocator : Loaded RoutePredicateFactory [CloudFoundryRouteService] 2020-05-10 14:33:45.335 INFO 1272 --- [ main] c.g.r.DynamicRouteServiceImplByNacos : update route : RouteDefinition{id='provider-router', predicates=[PredicateDefinition{name='Path', args={pattern=/provide/**}}], filters=[], uri=lb://nacos-provider, order=2, metadata={}} 2020-05-10 14:33:45.335 INFO 1272 --- [ main] c.g.service.DynamicRouteServiceImpl : gateway add route RouteDefinition{id='provider-router', predicates=[PredicateDefinition{name='Path', args={pattern=/provide/**}}], filters=[], uri=lb://nacos-provider, order=2, metadata={}} 2020-05-10 14:33:45.336 INFO 1272 --- [ main] c.g.r.DynamicRouteServiceImplByNacos : update route : RouteDefinition{id='github-router', predicates=[PredicateDefinition{name='Path', args={pattern=/github}}], filters=[], uri=https://github.com, order=3, metadata={}} 2020-05-10 14:33:45.336 INFO 1272 --- [ main] c.g.service.DynamicRouteServiceImpl : gateway add route RouteDefinition{id='github-router', predicates=[PredicateDefinition{name='Path', args={pattern=/github}}], filters=[], uri=https://github.com, order=3, metadata={}}
但这只能说明是初始化静态路由，下面我们改变gateway-router网关配置内容，追加github-router路由
[{ "id": "consumer-router", "order": 0, "predicates": [{ "args": { "pattern": "/consume/**" }, "name": "Path" }], "uri": "lb://nacos-consumer" },{ "id": "provider-router", "order": 2, "predicates": [{ "args": { "pattern": "/provide/**" }, "name": "Path" }], "uri": "lb://nacos-provider" },{ "id": "github-router", "order": 2, "predicates": [{ "args": { "pattern": "/github/**" }, "name": "Path" }], "uri": "https://github.com" }]
之后点击发布更新路由配置
观察gateway服务日志，有没有监听，并且进行正确的路由更新：如下日志所示，最新路由配置立马被打印，并且进行正确路由更新
2020-05-10 14:42:27.576 INFO 1272 --- [d5-b0a8fbeed8ea] c.g.r.DynamicRouteServiceImplByNacos : 进行网关更新: [{ "id": "consumer-router", "order": 0, "predicates": [{ "args": { "pattern": "/consume/**" }, "name": "Path" }], "uri": "lb://nacos-consumer" },{ "id": "provider-router", "order": 2, "predicates": [{ "args": { "pattern": "/provide/**" }, "name": "Path" }], "uri": "lb://nacos-provider" },{ "id": "github-router", "order": 2, "predicates": [{ "args": { "pattern": "/github/**" }, "name": "Path" }], "uri": "https://github.com" }] 2020-05-10 14:42:27.576 INFO 1272 --- [d5-b0a8fbeed8ea] c.g.r.DynamicRouteServiceImplByNacos : update route : RouteDefinition{id='consumer-router', predicates=[PredicateDefinition{name='Path', args={pattern=/consume/**}}], filters=[], uri=lb://nacos-consumer, order=0, metadata={}} 2020-05-10 14:42:27.576 INFO 1272 --- [d5-b0a8fbeed8ea] c.g.service.DynamicRouteServiceImpl : gateway update route RouteDefinition{id='consumer-router', predicates=[PredicateDefinition{name='Path', args={pattern=/consume/**}}], filters=[], uri=lb://nacos-consumer, order=0, metadata={}} 2020-05-10 14:42:27.578 INFO 1272 --- [d5-b0a8fbeed8ea] c.g.r.DynamicRouteServiceImplByNacos : update route : RouteDefinition{id='provider-router', predicates=[PredicateDefinition{name='Path', args={pattern=/provide/**}}], filters=[], uri=lb://nacos-provider, order=2, metadata={}} 2020-05-10 14:42:27.578 INFO 1272 --- [d5-b0a8fbeed8ea] c.g.service.DynamicRouteServiceImpl : gateway update route RouteDefinition{id='provider-router', predicates=[PredicateDefinition{name='Path', args={pattern=/provide/**}}], filters=[], uri=lb://nacos-provider, order=2, metadata={}} 2020-05-10 14:42:27.580 INFO 1272 --- [d5-b0a8fbeed8ea] c.g.r.DynamicRouteServiceImplByNacos : update route : RouteDefinition{id='github-router', predicates=[PredicateDefinition{name='Path', args={pattern=/github/**}}], filters=[], uri=https://github.com, order=2, metadata={}} 2020-05-10 14:42:27.580 INFO 1272 --- [d5-b0a8fbeed8ea] c.g.service.DynamicRouteServiceImpl : gateway update route RouteDefinition{id='github-router', predicates=[PredicateDefinition{name='Path', args={pattern=/github/**}}], filters=[], uri=https://github.com, order=2, metadata={}}
其实，还有办法可以知道我们的gateway服务有没有监听Nacos的gateway-router配置，那就是在Nacos Console--->监听查询----->选择配置---->输入配置文件的namespace与Group： 可以发现我本地IP地址127.0.0.1对配置文件gateway-router进行了监听
（2）访问gateway网关服务：http://localhost:6003/consume/sayHello/nacos
查看consumer服务日志：
2020-05-10 14:55:07.257 INFO 6552 --- [nio-6001-exec-2] c.n.c.controller.ConsumeController : I'm calling nacos-consumer service by dynamic gateway...
发现跳转至consumer服务，并且访问了consumer服务的CosnumerController
（3）访问gateway网关服务：http://localhost:6003/provider/sayHello/nacos
查看provider服务日志：
2020-05-10 14:56:56.144 INFO 10024 --- [nio-6002-exec-1] c.n.p.controller.ProviderController : I'm calling nacos-provider service by dynamic gateway...
发现跳转至consumer服务，并且访问了provider服务的ProviderController
（4）访问访问gateway网关服务：http://localhost:6003/github，正确跳转至github页面
四、总结
1）Spring Cloud Gateway作用不光只是简单的跳转重定向，还可以实现用户的验证登录，解决跨域，日志拦截，权限控制，限流，熔断，负载均衡，黑名单和白名单机制等。是微服务架构不二的选择；
2）Nacos的配置中心支持动态获取配置文件，可以将一些全局的经常变更的配置文件放在Nacos下，需要到微服务自行获取。