nacos 服务注册与发现代替Eureka。

• nacos-server

下载，安装，启动可以参考官方文档。本文章使用单机模式

nacos 替换Eureka 做服务注册中心

• pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>user</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>user</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud-alibaba.version>2.2.0.RELEASE</spring-cloud-alibaba.version>
        <spring-cloud.version>Hoxton.SR6</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>

<!--        <dependency>-->
<!--            <groupId>org.apache.dubbo</groupId>-->
<!--            <artifactId>dubbo-spring-boot-starter</artifactId>-->
<!--            <version>2.7.5</version>-->
<!--        </dependency>-->

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

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

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

• application.yml

server:
  port: 8888

spring:
  application:
    name: user-service
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848 # 注册中心地址

• UserApplication

@EnableFeignClients
@SpringBootApplication
@EnableDiscoveryClient // 使用该注解，开始服务注册
public class UserApplication {
    public static void main(String[] args) {
        SpringApplication.run(UserApplication.class, args);
    }

}

• nacos 管理界面

  
  

注意：虽然在这里使用的 nacos 作为注册中心，其他spring cloud Netflix 组件一样可以使用

• feign 调用

@FeignClient(value = "role-service")// 和以前一样
public interface RoleService {

    @GetMapping
    String role();

}

总结：我们简单的使用nacos 作为注册中心，算是入门操作。使用非常简单，其他更详细的使用可以参考官方文档。后面会开始分析nacos 作为注册的实现原理。