上篇文章講述了一個服務(wù)如何從配置中心讀取文件，配置中心如何從遠(yuǎn)程git讀取配置文件，當(dāng)服務(wù)實例很多時粮揉，都從配置中心讀取文件巡李，這時可以考慮將配置中心做成一個微服務(wù)，將其集群化扶认，從而達(dá)到高可用侨拦，架構(gòu)圖如下：

一，準(zhǔn)備工作

繼續(xù)使用上一篇文章的工程辐宾，創(chuàng)建一個eureka-server工程狱从，用作服務(wù)注冊中心。

在其pom.xml文件引入Eureka的起步依賴spring-cloud-starter-netflix- eureka-server叠纹，代碼如下:

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.example</groupId>
        <artifactId>demo2-springcloud</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <groupId>com.example</groupId>
    <artifactId>eureka-server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>eureka-server</name>
    <description>Demo project for Spring Boot</description>

    <dependencies>
        <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-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-config-server</artifactId>
        </dependency>
    </dependencies>

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

application.yml代碼

server:
  port: 8889

eureka:
  instance:
    hostname: localhost
  client:
    fetch-registry: false
    register-with-eureka: false
    service-url:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

在啟動類添加@EnableEurekaServer注解

package com.example.eurekaserver;

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

@EnableEurekaServer
@SpringBootApplication
public class EurekaServerApplication {

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

二季研，改造config-server

將其注冊微到服務(wù)注冊中心，作為Eureka客戶端,pom添加eureka依賴

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>

修改application.yml配置文件

spring:
  application:
    name: config-server
  cloud:
    config:
      server:
        git:
          uri: https://github.com/forezp/SpringcloudConfig/
          search-paths: respo
          password:
          username:
      label: master
server:
  port: 8888
eureka:
  client:
    service-url:
      defaultZone: http://localhost:8889/eureka/

在啟動類添加注解

package com.example.configserver;

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

@EnableEurekaClient
@EnableConfigServer
@SpringBootApplication
public class ConfigServerApplication {

    public static void main(String[] args) {
        SpringApplication.run(ConfigServerApplication.class, args);
    }
}

三誉察，改造config-client

將其注冊微到服務(wù)注冊中心与涡，作為Eureka客戶端,pom添加依賴

<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>

在啟動類添加@EnableEurekaClient注解

package com.example.configclient;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@EnableEurekaClient
@RestController
@SpringBootApplication
public class ConfigClientApplication {

    public static void main(String[] args) {
        SpringApplication.run(ConfigClientApplication.class, args);
    }

    @Value("${democonfigclient.message}")
    String message;
    @RequestMapping("/hi")
    public String sayHi(){
        return message;
    }
}

配置文件bootstrap.properties，注意是bootstrap!修改bootstrap.yml

spring:
  application:
    name: config-client
  cloud:
    config:
      label: master
      profile: dev
      uri: http://localhost:8888/eureka/
      name: config-client
      discovery:
        enabled: true
        service-id: config-server
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8889/eureka/
server:
  port: 8881

• spring.cloud.config.discovery.enabled 是從配置中心讀取文件持偏。
• spring.cloud.config.discovery.serviceId 配置中心的servieId驼卖，即服務(wù)名。

這時發(fā)現(xiàn)鸿秆，在讀取配置文件不再寫ip地址酌畜，而是服務(wù)名，這時如果配置服務(wù)部署多份卿叽，通過負(fù)載均衡桥胞，從而高可用。
依次啟動eureka-servr,config-server,config-client
訪問網(wǎng)址：http://localhost:8889/

四贩虾，易錯總結(jié)

1.config-client的配置文件修改是在bootstrap.yml上
2.注冊服務(wù)中心的路徑不能不一樣，不小心打錯了蕉扮，排查了幾個小時整胃。。喳钟。屁使。
3.啟動類添加的是@EnableEurekaClient不是@EnableEurekaServer

五，參考資料

大佬的文章https://blog.csdn.net/forezp/article/details/70037513