原创

第七篇 : 高可用的分布式配置中心(Spring Cloud Config)


简介

上一篇文章讲述了一个服务如何从配置中心读取文件,配置中心如何从远程git读取配置文件,当服务实例很多时,都从配置中心读取文件,这时可以考虑将配置中心做成一个微服务,将其集群化,从而达到高可用,架构图如下:
![](http://image.itwolfed.com/springcloud-7/高可用Spring Cloud Config.png)

一、创建项目

继续使用上一篇文章的工程,备创代码,复制成新的工程使用

1. 创建 eureka-server

创建eureka-server工程,用作服务注册中心

1. pom.xml

在其pom.xml文件引入Eureka的起步依赖spring-cloud-starter-netflix- eureka-server,代码如下:

<?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>

	<groupId>com.gf</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>

	<parent>
		<groupId>com.gf</groupId>
		<artifactId>chapter07</artifactId>
		<version>0.0.1-SNAPSHOT</version>
	</parent>

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

	</dependencies>


</project>

2. applicaton.yml

在配置文件application.yml上,指定服务端口为8889,加上作为服务注册中心的基本配置,代码如下:

server:
  port: 8889
eureka:
  instance:
    hostname: localhost
  client:
    register-with-eureka: false
    fetch-registry: false
    service-url:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

3. 主启动类 EurekaServerApplication

package com.gf;

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

@SpringBootApplication
@EnableEurekaServer
public class EurekaServerApplication {

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

2. 改造 config-server

1. pom.xml

在其pom.xml文件加上EurekaClient的起步依赖spring-cloud-starter-netflix-eureka-server,代码如下:

<?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>

	<groupId>com.gf</groupId>
	<artifactId>config-server</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>config-server</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>com.gf</groupId>
		<artifactId>chapter07</artifactId>
		<version>0.0.1-SNAPSHOT</version>
	</parent>

	<dependencies>
		<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>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
		</dependency>
	</dependencies>


</project>

2. application.yml

配置文件application.yml,指定服务注册地址为http://localhost:8889/eureka/,其他配置同上一篇文章,完整的配置如下:

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

3. 主启动类 ConfigServerApplication

最后需要在程序的启动类Application加上@EnableEurekaClient的注解。

package com.gf;

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;

@SpringBootApplication
@EnableConfigServer
@EnableEurekaClient
public class ConfigServerApplication {

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

3. 改造 config-client

1. pom.xml

将其注册微到服务注册中心,作为Eureka客户端,需要pom文件加上起步依赖spring-cloud-starter-netflix-eureka-server,代码如下:

<?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>

	<groupId>com.gf</groupId>
	<artifactId>config-client</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>config-client</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>com.gf</groupId>
		<artifactId>chapter07</artifactId>
		<version>0.0.1-SNAPSHOT</version>
	</parent>

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

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
		</dependency>
	</dependencies>


</project>

2. bootstrap.yml

配置文件bootstrap.yml,注意是bootstrap。加上服务注册地址为http://localhost:8889/eureka/

spring:
  application:
    name: config-client
  cloud:
    config:
      label: master
      profile: dev
      #uri: http://localhost:8888/
      discovery:
        enabled: true
        service-id: config-server
server:
  port: 8881
eureka:
  client:
    service-url:
      defaultZone: http://localhost:8889/eureka/
  • spring.cloud.config.discovery.enabled 是从配置中心读取文件。
  • spring.cloud.config.discovery.serviceId 配置中心的servieId,即服务名。

这时发现,在读取配置文件不再写ip地址,而是服务名,这时如果配置服务部署多份,通过负载均衡,从而高可用。

依次启动eureka-servr,config-server,config-client
访问网址:http://localhost:8889/

访问http://localhost:8881/hi,浏览器显示:

dev

源码下载:https://github.com/gf-huanchupk/SpringCloudLearning

springcloud
  • 作者:程序员果果
  • 发表时间:2018-09-28 20:51
  • 版权声明:自由转载-非商用-非衍生-保持署名 (创意共享4.0许可证)
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