SpringCloud-2.0-周阳（18. 服务注册发现 - Nacos）

男娘i 2023-09-28 12:19 24阅读 0赞

[上一篇 ：17. SpringCloud Alibaba入门简介][_17. SpringCloud Alibaba]

[下一篇 ：19. 分布式配置中心 - Nacos][_19. _ - Nacos]

*  **声明：原文作者：csdn：yuan\_404**

### 文章目录 ###

*  1 . Nacos 简介
 *   *  1.1 为什么叫Nacos
     *  1.2 是什么
     *  1.3 能干嘛
     *  1.4 与其他注册中心的对比
 *  2 . 安装并运行
 *  3 . 服务注册发现
 *   *  3.1 服务提供者 - Provider
     *  3.2 服务消费者 - Consumer
     *  3.3 各种注册中心进一步对比

# 1 . Nacos 简介 #

*  Github ：[https://github.com/alibaba/Nacos][https_github.com_alibaba_Nacos]
 *  官网 ：[https://nacos.io/zh-cn/index.html][https_nacos.io_zh-cn_index.html]
 *  官方文档 ：[https://spring-cloud-alibaba-group.github.io/github-pages/greenwich/spring-cloud-alibaba.html\#\_spring\_cloud\_alibaba\_nacos\_discovery][https_spring-cloud-alibaba-group.github.io_github-pages_greenwich_spring-cloud-alibaba.html_spring_cloud_alibaba_nacos_discovery]

## 1.1 为什么叫Nacos ##

*  NA ：前两个字母是 Naming（服务命名管理 ） 的前两个字母
 *  CO ：中间两个字母是 Configuration（服务配置） 的前两个字母
 *  S ：最后一个为 Service 的第一个
 *  Nacos：Dynamic Naming and Configuration Service（动态命名和配置服务）

## 1.2 是什么 ##

*  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中心
 *  Nacos就是注册中心+配置中心的组合
 *  等价于 Netflix 中的 Eureka+Config+Bus

## 1.3 能干嘛 ##

*  替代 Eureka 做服务**注册中心**
 *  替代 Config 做服务**配置中心**

## 1.4 与其他注册中心的对比 ##

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ0OTgzOA_size_16_color_FFFFFF_t_70][]

# 2 . 安装并运行 #

1.  本地需要有 Java-8、Maven 的环境
2.  从官方的 GIT 上下载
    
    Github 下载地址 ：[https://github.com/alibaba/nacos/releases/tag/1.1.4][https_github.com_alibaba_nacos_releases_tag_1.1.4]
3.  解压安装包，直接运行bin目录下的startup.cmd  
    ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ0OTgzOA_size_16_color_FFFFFF_t_70 1][]
4.  命令运行成功后直接访问 [http://localhost:8848/nacos][http_localhost_8848_nacos]  
    ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ0OTgzOA_size_16_color_FFFFFF_t_70 2][]
5.  用户名 、密码 都是 nacos  
    ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ0OTgzOA_size_16_color_FFFFFF_t_70 3][]

*  安装成功

# 3 . 服务注册发现 #

## 3.1 服务提供者 - Provider ##

1.  新建模块 ：alibaba-provider-payment-9001
2.  修改 POM

*  父 POM
    
        
        <dependency>
        	<groupId>com.alibaba.cloud</groupId>
        	<artifactId>spring-cloud-alibaba-dependencies</artifactId>
        	<version>2.1.0.RELEASE</version>
        	<type>pom</type>
        	<scope>import</scope>
        </dependency>
 *  本模块的 POM
    
        <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>1.2.73</version>
            </dependency>
        </dependencies>

1.  编写 YML
    
        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: '*'
2.  编写主启动类
    
        @SpringBootApplication
        @EnableDiscoveryClient
        public class PaymentMain9001 {
              
            public static void main(String[] args) {
              
                SpringApplication.run(PaymentMain9001.class, args);
            }
        }
3.  业务类

*  Controller ：PaymentController
    
        @RestController
        public class PaymentController {
              
            @Value("${server.port}")
            private String serverPort;
        
            @GetMapping(value = "/payment/nacos/{id}")
            public String getPayment(@PathVariable("id") Integer id) {
              
                return "nacos registry, serverPort: "+ serverPort+"\t id"+id;
            }
        }

1.  测试
    
    启动 Necos、alibaba-provider-payment-9001
    
    查看 Nacos 界面
    
    ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ0OTgzOA_size_16_color_FFFFFF_t_70 4][]
2.  在 alibaba-provider-payment-9001 的基础上再创建一个一模一样的项目 alibaba-provider-payment-9002 ，为了搭建一个简单的集群

*  如果不想创建新项目，可以使用以下方法

> ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ0OTgzOA_size_16_color_FFFFFF_t_70 5][]
> 
> ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ0OTgzOA_size_16_color_FFFFFF_t_70 6][]
> 
> ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ0OTgzOA_size_16_color_FFFFFF_t_70 7][]

1.  再查看 Nacos 的界面  
    ![20201218211601823.png][]

## 3.2 服务消费者 - Consumer ##

1.  新建模块 ：alibaba-consumer-nacos-order-83
2.  修改 POM
    
        <dependencies>
            
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
            </dependency>
            <dependency>
                <groupId>com.demo.springcloud</groupId>
                <artifactId>cloud-api-commons</artifactId>
                <version>${project.version}</version>
            </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>
3.  编写 YML
    
        server:
          port: 83
        
        spring:
          application:
            name: nacos-order-consumer
          cloud:
            nacos:
              discovery:
                server-addr: localhost:8848
        # 消费者要去访问的微服务名称
        service-url:
          nacos-user-service: http://nacos-payment-provider
4.  编写主启动类
    
        @EnableDiscoveryClient
        @SpringBootApplication
        public class OrderNacosMain83 {
              
            public static void main(String[] args) {
              
                SpringApplication.run(OrderNacosMain83.class,args);
            }
        }
5.  业务类

*  Config ：ApplicationContextBean
    
    这部分和之前使用 Ribbon 一样的写
    
        @Configuration
        public class ApplicationContextBean {
              
            @Bean
            @LoadBalanced
            public RestTemplate getRestTemplate(){
              
                return new RestTemplate();
            }
        }
 *  Controller ：OrderNacosController
    
        @RestController
        @Slf4j
        public class OrderNacosController {
              
            @Value("${service-url.nacos-user-service}")
            private String SERVER_URL;
        
            @Autowired
            private  RestTemplate restTemplate;
        
            @GetMapping(value = "/consumer/payment/nacos/{id}")
            public String getPayment(@PathVariable("id") Integer id) {
              
                return restTemplate.getForObject(SERVER_URL+"/payment/nacos/"+id, String.class);
            }
        }

1.  测试
    
    启动 Nacos 控制台  
    启动 9001、9002、83  
    ![20201219102612682.png][]
    
    ![2020121910262388.png][]
    
    访问 ：[http://localhost:83/consumer/payment/nacos/111][http_localhost_83_consumer_payment_nacos_111]  
    ![20201219103226268.png][]
    
    ![20201219103302620.png][]

## 3.3 各种注册中心进一步对比 ##

*  前面只是简单对比了一下，下面会更深层的对比
 *  **Nacos全景图**  
    ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ0OTgzOA_size_16_color_FFFFFF_t_70 8][]
 *  **Nacos 和 CAP**  
    ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ0OTgzOA_size_16_color_FFFFFF_t_70 9][]
    
    ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ0OTgzOA_size_16_color_FFFFFF_t_70 10][]
 *  **Nacos支持AP和CP模式的切换**

>  *  C是所有节点在同一时间看到的数据是一致的
>  *  A的定义是所有的请求都会收到响应。

>  *  一般来说，如果不需要存储服务级别的信息且服务实例是通过nacos-client注册，并能够保持心跳上报，那么就可以选择AP模式。当前主流的服务如 Sping cloud和Dubbo服务，都适用于AP模式，AP模式为了服务的可能性而减弱了一致性，因此AP模式下只支持注册临时实例。
>  *  如果需要在服务级别编辑或者存储配置信息，那么CP是必须，K8S服务和DNS服务则适用于CP模式.  
>     CP模式下则支持注册持久化实例，此时则是以Raft协议为集群运行模式，该模式下注册实例之前必须先注册服务，如果服务不存在，则会返回错误。

>  *  切换命令 ：`curl -X PUT '$NACOS_SERVER:8848/nacos/v1/ns/operator/switches?entry=serverMode&value=CP'`

[_17. SpringCloud Alibaba]: https://blog.csdn.net/Mango_Bin/article/details/125474515
[_19. _ - Nacos]: https://blog.csdn.net/Mango_Bin/article/details/125475316
[https_github.com_alibaba_Nacos]: https://github.com/alibaba/Nacos
[https_nacos.io_zh-cn_index.html]: https://nacos.io/zh-cn/index.html
[https_spring-cloud-alibaba-group.github.io_github-pages_greenwich_spring-cloud-alibaba.html_spring_cloud_alibaba_nacos_discovery]: https://spring-cloud-alibaba-group.github.io/github-pages/greenwich/spring-cloud-alibaba.html#_spring_cloud_alibaba_nacos_discovery
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[https_github.com_alibaba_nacos_releases_tag_1.1.4]: https://github.com/alibaba/nacos/releases/tag/1.1.4
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[http_localhost_8848_nacos]: http://localhost:8848/nacos
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[20201218211601823.png]: https://img-blog.csdnimg.cn/20201218211601823.png
[20201219102612682.png]: https://img-blog.csdnimg.cn/20201219102612682.png
[2020121910262388.png]: https://img-blog.csdnimg.cn/2020121910262388.png
[http_localhost_83_consumer_payment_nacos_111]: http://localhost:83/consumer/payment/nacos/111
[20201219103226268.png]: https://img-blog.csdnimg.cn/20201219103226268.png
[20201219103302620.png]: https://img-blog.csdnimg.cn/20201219103302620.png
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