nacos 服务注册与配置中心

青旅半醒 2022-12-11 09:29 147阅读 0赞

## 一、服务注册 ##

在本地启动 navcos 服务器：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzk0MTM2NA_size_16_color_FFFFFF_t_70_pic_center][]

然后导入依赖：

<dependencies>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</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.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </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>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.62</version>
        </dependency>
    </dependencies>

然后是配置文件：

server:
      port: 9001
    
    spring:
      application:
        name: nacos-payment-provider
      cloud:
        nacos:
          discovery:
            server-addr: localhost:8848 #配置 Nacos 地址
    management:
      endpoints:
        web:
          exposure:
            include: '*'

这里配置文件指定了访问的本地的 `8848` 端口。

主启动类，加上 `@EnableDiscoveryClient` 注解作为服务发现：

@SpringBootApplication
    @EnableDiscoveryClient
    public class PaymentMain9001 { 
        public static void main(String[] args) { 
            SpringApplication.run(PaymentMain9001.class, args);
        }
    }

启动服务之后，访问 `http://localhost:8848/nacos/#/serviceManagement` 即可看到以下信息：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzk0MTM2NA_size_16_color_FFFFFF_t_70_pic_center 1][]  
**负载均衡**

因为 `nacos` 集成了 `ribbon`，所以支持负载均衡：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzk0MTM2NA_size_16_color_FFFFFF_t_70_pic_center 2][]  
在消费者端，配置 `ApplicationContextConfig`，在 Template 上加上 `@LoadBalanced` 注解开启负载均衡。

@Configuration
    public class ApplicationContextConfig { 
    
        @Bean
        @LoadBalanced
        public RestTemplate getRestTemplate() { 
            return new RestTemplate();
        }
    }

## 二、配置中心 ##

pom 文件如下：

<dependencies>
        
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
        </dependency>
        
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</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.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </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>

bootstrap：

server:
      port: 3377
    
    spring:
      application:
        name: nacos-config-client
      cloud:
        nacos:
          discovery:
            server-addr: localhost:8848
          config:
            server-addr: localhost:8848
            file-extension: yaml
    
    # 根据公式得到地址为: nacos-config-client-dev.yaml

application：

spring:
      profiles:
        active: dev

业务类如下，记得加上 `@RefreshScope` 注解：

@RestController
    @Slf4j
    @RefreshScope
    public class ConfigClientController { 
        @Value("${config.info}")
        private String configInfo;
    
        @GetMapping("/config/info")
        public String getConfigInfo() { 
            return configInfo;
        }
    }

关于配置匹配，有一个公式：

${ spring.application.name}-${ spring.profile.active}.${ spring.cloud.nacos.config.file-extension}

根据公式，我们这里的 Data Id 应该是：

nacos-config-client-dev.yaml

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzk0MTM2NA_size_16_color_FFFFFF_t_70_pic_center 3][]  
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自带动态刷新，不需要我们通过消息总线发广播。

> 修改下 Nacos 中的 yaml 配置文件，再次调用查看配置的接口，就会发现配置已经刷新

Namespace + Group + Data ID 三者关系？

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzk0MTM2NA_size_16_color_FFFFFF_t_70_pic_center 5][]  
这三者的关系像是文件系统的分级目录一样，`NameSpace` 最大。

配置 `GROUP` 和 `NameSpace` 如下图所示：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzk0MTM2NA_size_16_color_FFFFFF_t_70_pic_center 6][]

config:
      server-addr: localhost:8848
      file-extension: yaml
      namespace: asdasqe2e12312e1dasdad
      group: TEST

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