Nacos下动态路由配置

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:\r\n{}",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:\n\r{}",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\n\r");
                    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。