springcloud eureka注冊中心分布式配置

　　最近在學習springcloud，做下筆記以及記下遇到的坑。

1.建立maven工程，結構很簡單，一個啟動類和一個配置文件，結構如下圖所示

2.啟動類代碼如下，需要添加注冊中心注解：EnableEurekaServer

package com.chendb.eureka;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

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

3.配置文件application.yml如下代碼，在這里遇到了一個坑，項目能夠成功啟動，但是訪問配置中心一直報404，經過查詢，是因為freemarker的viewResolver沒有在spring-cloud-netflix-eureka-server-2.1.0.RELEASE.jar中找到模板，導致訪問注冊中心報404，故需要在配置文件加上

spring:

  freemarker:
    prefer-file-system-access: false

這里一共配置了三個配置中心，可通過替換配置分別啟動，形成分布式

spring:
  profiles:
    active: dev1
  # freemarker的viewResolver沒有在spring-cloud-netflix-eureka-server-1.3.1.RELEASE.jar中找到模板，導致訪問注冊中心報404
  freemarker:
    prefer-file-system-access: false

---
spring:
  application:
    ###當前服務名
    name: eureka-peer
  profiles: dev

server:
  ##端口號
  port: 10000

---
spring:
  profiles: dev1
  application:
    name: eureka-peer2
server:
  port: 10001
  
---
spring:
   profiles: dev2
   application:
     name: eureka-peer3
server:
  port: 10002

---
eureka:
  instance:
    hostname: dev1
  client:
    ##檢索服務
    fetch-registry: false
    ##是否將自己注冊到eureka
    register-with-eureka: false
    ##客戶端默認去這個地址找注冊中心
    service-url:
      defaultZone: http://localhost:10000/eureka/,http://localhost:10001/eureka/,http://localhost:10002/eureka/
  server:
    ### 當eureka啟動時，不能從集群節點中獲取到instance注冊信息，應該等多久
    wait-time-in-ms-when-sync-empty: 0
    enable-self-preservation: true
    ###eureka多長時間更新一次數據
    peer-eureka-nodes-update-interval-ms: 100000

3.pom.xml文件

<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 http://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>2.1.3.RELEASE</version>
      <relativePath/> <!-- lookup parent from repository -->
  </parent>
  <groupId>spring-cloud-eureka-server</groupId>
  <artifactId>spring-cloud-eureka-server</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>spring-cloud-eureka-server</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <java.version>1.8</java.version>
    <spring-cloud.version>Greenwich.RELEASE</spring-cloud.version>
  </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

        <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>

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </repository>
    </repositories>
</project>

4.運行啟動類，訪問http://localhost:10001即可，如下圖

5.配置客戶端，客戶端代碼結構如下

6.客戶端啟動類的配置文件如下

package com.chendb.eureka;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

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

spring:
  application:
    name: eureka-client
  # freemarker的viewResolver沒有在spring-cloud-netflix-eureka-server-1.3.1.RELEASE.jar中找到模板，導致訪問注冊中心報404
  freemarker:
    prefer-file-system-access: false
    
server:
  port: 8001
  
eureka:
  client:
    service-url:
      defaultZone: http://localhost:10000/eureka/,http://localhost:10001/eureka/,http://localhost:10002/eureka/

7.啟動后可以看到該客戶端已經被注冊到服務端