SpringCloud之Eureka服务注册与发现(一)

一 Eureka的基本架构

Spring Cloud 封装了 Netflix 公司开发的 Eureka 模块来实现服务注册和发现(请对比Zookeeper)。

Eureka 采用了 C-S 的设计架构。Eureka Server 作为服务注册功能的服务器，它是服务注册中心。

而系统中的其他微服务，使用 Eureka 的客户端连接到 Eureka Server并维持心跳连接。这样系统的维护人员就可以通过 Eureka Server 来监控系统中各个微服务是否正常运行。SpringCloud 的一些其他模块（比如Zuul）就可以通过 Eureka Server 来发现系统中的其他微服务，并执行相关的逻辑。

二 Eureka的三大角色

    

• Eureka Server 提供服务注册和发现

• Service Provider服务提供方将自身服务注册到Eureka，从而使服务消费方能够找到

• Service Consumer服务消费方从Eureka获取注册服务列表，从而能够消费服务

三 构建步骤

• 创建eureka-server项目

  • pom.xml

  ​
    

   <dependencies>
          <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-web</artifactId>
          </dependency>
          <dependency>
              <groupId>org.springframework.cloud</groupId>
              <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
          </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>
          </dependencies>
      </dependencyManagement>
  ​
      <build>
          <plugins>
              <plugin>
                  <groupId>org.springframework.boot</groupId>
                  <artifactId>spring-boot-maven-plugin</artifactId>
              </plugin>
          </plugins>
      </build>

  • yml

    server:
      port: 8761
    ​
    eureka:
      instance:
        hostname: localhost
      client:
        registerWithEureka: false
        fetchRegistry: false
        serviceUrl:
          defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

  • 启动类

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

  • 启动结果

    

• 创建producer-service

  • pom.xml

     1   <dependencies>
     2         <dependency>
     3             <groupId>org.springframework.boot</groupId>
     4             <artifactId>spring-boot-starter-actuator</artifactId>
     5         </dependency>
     6         <dependency>
     7             <groupId>org.springframework.boot</groupId>
     8             <artifactId>spring-boot-starter-web</artifactId>
     9         </dependency>
    10         <dependency>
    11             <groupId>org.springframework.cloud</groupId>
    12             <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    13         </dependency>
    14 ​
    15         <dependency>
    16             <groupId>org.springframework.boot</groupId>
    17             <artifactId>spring-boot-starter-test</artifactId>
    18             <scope>test</scope>
    19         </dependency>
    20     </dependencies>
    21 ​
    22     <dependencyManagement>
    23         <dependencies>
    24             <dependency>
    25                 <groupId>org.springframework.cloud</groupId>
    26                 <artifactId>spring-cloud-dependencies</artifactId>
    27                 <version>${spring-cloud.version}</version>
    28                 <type>pom</type>
    29                 <scope>import</scope>
    30             </dependency>
    31         </dependencies>
    32     </dependencyManagement>
    33     <!-- 微服务info内容详细信息 -->
    34     <build>
    35         <finalName>microservicecloud</finalName>
    36         <resources>
    37             <resource>
    38                 <directory>src/main/resources</directory>
    39                 <filtering>true</filtering>
    40             </resource>
    41         </resources>
    42         <plugins>
    43             <plugin>
    44                 <groupId>org.apache.maven.plugins</groupId>
    45                 <artifactId>maven-resources-plugin</artifactId>
    46                 <configuration>
    47                     <delimiters>
    48                         <delimit>$</delimit>
    49                     </delimiters>
    50                 </configuration>
    51             </plugin>
    52         </plugins>
    53     </build>

  • yml

    eureka:
      client:
        serviceUrl:
          defaultZone: http://localhost:8761/eureka/
      instance:         
        instance-id: product-service8080    #主机名称:服务名称修改
        prefer-ip-address: true   #访问路径可以显示IP地址
    ​
    server:
      port: 8080
    spring:
      application:
        name: product-service
    #微服务info内容详细信息
    info:
      app.name: product-servic
      company.name: www.topcheer.com

  • 启动类

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

  • 结果：