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使用 Nacos 作为服务注册中心

程序员文章站 2022-07-15 09:05:53
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认识 Nacos

Nacos

  • 一个更易于构建云原生应用的动态服务发现、配置管理和服务管理平台，是阿里巴巴开源的组件。
  • 官网文档 https://nacos.io/zh-cn/index.html

功能

  • 动态服务配置

  • 服务发现和管理

  • 动态 DNS 服务
    通过访问域名的方式 去访问我的服务 替我们做负载均衡 在一些不能改动的基础设施上 通过这样的域名 去做访问

使用 Nacos 作为服务注册中心
Config Service（服务的配置服务） 和 Naming Service（服务注册与发现） 是重要部分
服务的消费者和提供者可以通过服务的名字 互相找到对方

使用 Nacos 作为注册中心

Spring Cloud Alibaba

  • 引入 spring-cloud-alibaba-dependencies 依赖

  • 替换为 spring-cloud-starter-alibaba-nacos-discovery

简单配置

  • spring.cloud.nacos.discovery.server-addr
    配置地址

通过 Docker 启动 Nacos

官方指引

  • https://hub.docker.com/r/nacos/nacos-server

获取镜像

  • docker pull nacos/nacos-server

运行 Nacos 镜像

  • docker run --name nacos -d -p 8848:8848 -e MODE=standalone nacos/nacos-server
  • 用户名密码为 nacos

源码

目录
使用 Nacos 作为服务注册中心
spring.factories

org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
  org.springframework.cloud.alibaba.nacos.NacosDiscoveryAutoConfiguration,\
  //进行了NacosDiscovery ribbon 的自动配置
  org.springframework.cloud.alibaba.nacos.ribbon.RibbonNacosAutoConfiguration,\
  org.springframework.cloud.alibaba.nacos.endpoint.NacosDiscoveryEndpointAutoConfiguration
org.springframework.cloud.client.discovery.EnableDiscoveryClient=\
org.springframework.cloud.alibaba.nacos.NacosDiscoveryClientAutoConfiguration

NacosDiscoveryAutoConfiguration

@Configuration
@EnableConfigurationProperties
@ConditionalOnNacosDiscoveryEnabled
@ConditionalOnClass(
    name = {"org.springframework.boot.web.servlet.context.ServletWebServerInitializedEvent"}
)
@ConditionalOnProperty(
    value = {"spring.cloud.service-registry.auto-registration.enabled"},
    matchIfMissing = true
)
@AutoConfigureBefore({AutoServiceRegistrationAutoConfiguration.class, NacosDiscoveryClientAutoConfiguration.class})
public class NacosDiscoveryAutoConfiguration {
    public NacosDiscoveryAutoConfiguration() {
    }

    @Bean
    public NacosServiceRegistry nacosServiceRegistry() {
        return new NacosServiceRegistry();//做了一个NacosServiceRegistry  进入该方法
    }

    @Bean
    @ConditionalOnBean({AutoServiceRegistrationProperties.class})
    public NacosRegistration nacosRegistration() {
        return new NacosRegistration();//做了一个NacosRegistration
    }

    @Bean
    @ConditionalOnBean({AutoServiceRegistrationProperties.class})
    public NacosAutoServiceRegistration nacosAutoServiceRegistration(NacosServiceRegistry registry, AutoServiceRegistrationProperties autoServiceRegistrationProperties, NacosRegistration registration) {
        return new NacosAutoServiceRegistration(registry, autoServiceRegistrationProperties, registration);
    }//配了一个自动的注册
}

NacosServiceRegistry

public class NacosServiceRegistry implements ServiceRegistry<NacosRegistration> {
    private static Logger logger = LoggerFactory.getLogger(NacosServiceRegistry.class);

    public NacosServiceRegistry() {
    }

    public void register(NacosRegistration registration) {
        if (!registration.isRegisterEnabled()) {
            logger.info("Nacos Registration is disabled...");
        } else if (StringUtils.isEmpty(registration.getServiceId())) {
            logger.info("No service to register for nacos client...");
        } else {
            NamingService namingService = registration.getNacosNamingService();
            //通过 namingService 取得 registration 的Serviceid 
            String serviceId = registration.getServiceId();
            Instance instance = new Instance();
            instance.setIp(registration.getHost());
            instance.setPort(registration.getPort());
            instance.setWeight((double)registration.getRegisterWeight());
            instance.setClusterName(registration.getCluster());
            instance.setMetadata(registration.getMetadata());
			//配置好Instance 
            try {
                namingService.registerInstance(serviceId, instance);
                //将它一起注册上去
                logger.info("nacos registry, {} {}:{} register finished", new Object[]{serviceId, instance.getIp(), instance.getPort()});
            } catch (Exception var6) {
                logger.error("nacos registry, {} register failed...{},", new Object[]{serviceId, registration.toString(), var6});
            }

        }
    }

    public void deregister(NacosRegistration registration) {
        logger.info("De-registering from Nacos Server now...");
        if (StringUtils.isEmpty(registration.getServiceId())) {
            logger.info("No dom to de-register for nacos client...");
        } else {
            NamingService namingService = registration.getNacosNamingService();
            String serviceId = registration.getServiceId();

            try {
                namingService.deregisterInstance(serviceId, registration.getHost(), registration.getPort(), registration.getCluster());
            } catch (Exception var5) {
                logger.error("ERR_NACOS_DEREGISTER, de-register failed...{},", registration.toString(), var5);
            }

            logger.info("De-registration finished.");
        }
    }

    public void close() {
    }

    public void setStatus(NacosRegistration registration, String status) {
    }

    public <T> T getStatus(NacosRegistration registration) {
        return null;
    }
}

NacosDiscoveryClient

public class NacosDiscoveryClient implements DiscoveryClient {
    private static final Logger LOGGER = LoggerFactory.getLogger(NacosDiscoveryClient.class);
    public static final String DESCRIPTION = "Spring Cloud Nacos Discovery Client";
    @Autowired
    private NacosDiscoveryProperties discoveryProperties;

    public NacosDiscoveryClient() {
    }

    public String description() {
        return "Spring Cloud Nacos Discovery Client";
    }

    public List<ServiceInstance> getInstances(String serviceId) {
        try {
            List<Instance> instances = this.discoveryProperties.namingServiceInstance().selectInstances(serviceId, true);
            //通过 namingServiceInstance 里面 取得 serviceId 对应的所有 Instance 的列表
            return hostToServiceInstanceList(instances, serviceId);//将它做了个转换返回
        } catch (Exception var3) {
            throw new RuntimeException("Can not get hosts from nacos server. serviceId: " + serviceId, var3);
        }
    }

    private static ServiceInstance hostToServiceInstance(Instance instance, String serviceId) {
        NacosServiceInstance nacosServiceInstance = new NacosServiceInstance();
        nacosServiceInstance.setHost(instance.getIp());
        nacosServiceInstance.setPort(instance.getPort());
        nacosServiceInstance.setServiceId(serviceId);
        Map<String, String> metadata = new HashMap();
        metadata.put("instanceId", instance.getInstanceId());
        metadata.put("weight", instance.getWeight() + "");
        metadata.put("healthy", instance.isHealthy() + "");
        metadata.put("cluster", instance.getClusterName() + "");
        metadata.putAll(instance.getMetadata());
        nacosServiceInstance.setMetadata(metadata);
        return nacosServiceInstance;
    }

    private static List<ServiceInstance> hostToServiceInstanceList(List<Instance> instances, String serviceId) {
        List<ServiceInstance> result = new ArrayList(instances.size());
        Iterator var3 = instances.iterator();

        while(var3.hasNext()) {
            Instance instance = (Instance)var3.next();
            result.add(hostToServiceInstance(instance, serviceId));
        }

        return result;
    }

    public List<String> getServices() {
        try {
            ListView<String> services = this.discoveryProperties.namingServiceInstance().getServicesOfServer(1, 2147483647);
            return services.getData();
        } catch (Exception var2) {
            LOGGER.error("get service name from nacos server fail,", var2);
            return Collections.emptyList();
        }
    }
}

我们通过springcloud提供的 DiscoveryClient 和 ServiceRegistry 这两层抽象 我们可以通过这两个抽象 去添加一套服务的注册发现机制 只要去实现它对应的接口 去做一个实现就行了

例子

目录
nacos-waiter-service
使用 Nacos 作为服务注册中心

nacos-customer-service

使用 Nacos 作为服务注册中心

需要修改的代码
nacos-waiter-service
application.properties

spring.jpa.hibernate.ddl-auto=none
spring.jpa.properties.hibernate.show_sql=true
spring.jpa.properties.hibernate.format_sql=true

management.endpoints.web.exposure.include=*
management.endpoint.health.show-details=always

info.app.author=DigitalSonic
info.app.encoding=@project.build.aaa@qq.com

server.port=0

spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848
#设置本地地址与端口

pom文件

<properties>
		<java.version>1.8</java.version>
		<spring-cloud.version>Greenwich.SR1</spring-cloud.version>
		<spring-cloud-alibaba.version>0.2.1.RELEASE</spring-cloud-alibaba.version>
		<!--设置版本号-->
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-cache</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-jpa</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-actuator</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
		</dependency>
		<!-- 替换掉 erueka -->
		<dependency>
			<groupId>io.micrometer</groupId>
			<artifactId>micrometer-registry-prometheus</artifactId>
		</dependency>

		<dependency>
			<groupId>org.joda</groupId>
			<artifactId>joda-money</artifactId>
			<version>1.0.1</version>
		</dependency>
		<dependency>
			<groupId>org.jadira.usertype</groupId>
			<artifactId>usertype.core</artifactId>
			<version>6.0.1.GA</version>
		</dependency>
		<!-- 增加Jackson的Hibernate类型支持 -->
		<dependency>
			<groupId>com.fasterxml.jackson.datatype</groupId>
			<artifactId>jackson-datatype-hibernate5</artifactId>
			<version>2.9.8</version>
		</dependency>

		<dependency>
			<groupId>org.apache.commons</groupId>
			<artifactId>commons-lang3</artifactId>
		</dependency>

		<dependency>
			<groupId>com.h2database</groupId>
			<artifactId>h2</artifactId>
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<dependencyManagement>
		<dependencies>
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-dependencies</artifactId>
				<version>${spring-cloud.version}</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-alibaba-dependencies</artifactId>
				<version>${spring-cloud-alibaba.version}</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
		<!-- 引入 spring-cloud-alibaba 支持 -->
	</dependencyManagement>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

nacos-customer-service
application.properties

server.port=0

management.endpoint.health.show-details=always

spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848
#设置地址

pom文件

<properties>
		<java.version>1.8</java.version>
		<spring-cloud.version>Greenwich.SR1</spring-cloud.version>
		<spring-cloud-alibaba.version>0.2.1.RELEASE</spring-cloud-alibaba.version>
		<!--alibaba版本号-->
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
		</dependency>
        <!--替换掉erueka-->
		<dependency>
			<groupId>org.joda</groupId>
			<artifactId>joda-money</artifactId>
			<version>1.0.1</version>
		</dependency>

		<dependency>
			<groupId>org.apache.commons</groupId>
			<artifactId>commons-lang3</artifactId>
		</dependency>

		<dependency>
			<groupId>org.apache.httpcomponents</groupId>
			<artifactId>httpclient</artifactId>
			<version>4.5.7</version>
		</dependency>

		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<dependencyManagement>
		<dependencies>
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-dependencies</artifactId>
				<version>${spring-cloud.version}</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-alibaba-dependencies</artifactId>
				<version>${spring-cloud-alibaba.version}</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
		<!--引入阿里巴巴依赖-->
	</dependencyManagement>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

结果分析

通过 Docker 使用 docker run --name nacos -d -p 8848:8848 -e MODE=standalone nacos/nacos-server 命令创建并打开一个nacos
在游览器上输入 localhost:8848/nacos 进入 nacos 页面
使用 Nacos 作为服务注册中心
使用 用户名 nacos 密码 naocs 登录
使用 Nacos 作为服务注册中心
这里 我们使用 服务管理
使用 Nacos 作为服务注册中心

运行 nacos-waiter-service 刷新页面 waiter-service 成功的注册了上去
使用 Nacos 作为服务注册中心

点击 详情 我们可以看到 waiter-service 的详细信息
使用 Nacos 作为服务注册中心

运行 nacos-customer-service 从控制台上 我们可以看到 成功的将自己注册进去 并找到 waiter-service 成功的访问到了 里面的数据
使用 Nacos 作为服务注册中心
使用 Nacos 作为服务注册中心

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