史上最简单的SpringCloud教程 | 第七篇: 高可用的分布式配置中心(Spring Cloud Config)

你的名字 2022-06-09 05:14 142阅读 0赞

目录[(?)][Link 1][\[+\]][Link 1]

> 转载请标明出处：   
> [http://blog.csdn.net/forezp/article/details/70037513][http_blog.csdn.net_forezp_article_details_70037513]   
> 本文出自[方志朋的博客][Link 2]

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][Link 3]，将其集群化，从而达到高可用，[架构][Link 4]图如下：

![Azure (3).png][Azure _3_.png]

### 一、准备工作 ###

继续使用上一篇文章的工程，创建一个eureka-server工程，用作服务注册中心。

在其pom.xml文件引入Eureka的起步依赖[spring][]\-cloud-starter-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.forezp</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>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.5.2.RELEASE</version>
            <relativePath/> 
        </parent>
    
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-eureka-server</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</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>Dalston.RC1</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>
                <snapshots>
                    <enabled>false</enabled>
                </snapshots>
            </repository>
        </repositories>
    
    
    </project>
    
       
        
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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:
        registerWithEureka: false
        fetchRegistry: false
        serviceUrl:
          defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/
       
        
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入口类：

@EnableEurekaServer
    @SpringBootApplication
    public class EurekaServerApplication { 
    
        public static void main(String[] args) {
            SpringApplication.run(EurekaServerApplication.class, args);
        }
    }
    
       
        
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### 二、改造config-server ###

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

<dependencies>
            <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-eureka</artifactId>
            </dependency>
        </dependencies>
    
       
        
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配置文件application.yml，指定服务注册地址为[http://localhost:8889/eureka/][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
    server.port=8888
    
    spring.cloud.config.server.git.uri=https://github.com/forezp/SpringcloudConfig/
    spring.cloud.config.server.git.searchPaths=respo
    spring.cloud.config.label=master
    spring.cloud.config.server.git.username= your username
    spring.cloud.config.server.git.password= your password
    eureka.client.serviceUrl.defaultZone=http://localhost:8889/eureka/
       
        
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最后需要在程序的启动类Application加上@EnableEureka的注解。

### 三、改造config-client ###

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-eureka，代码如下：

<dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-config</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-eureka</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
       
        
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配置文件bootstrap.properties，注意是bootstrap。加上服务注册地址为[http://localhost:8889/eureka/][http_localhost_8889_eureka]

spring.application.name=config-client
    spring.cloud.config.label=master
    spring.cloud.config.profile=dev
    #spring.cloud.config.uri= http://localhost:8888/
    
    eureka.client.serviceUrl.defaultZone=http://localhost:8889/eureka/
    spring.cloud.config.discovery.enabled=true
    spring.cloud.config.discovery.serviceId=config-server
    server.port=8881
    
    
       
        
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*  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/][http_localhost_8889]

![Paste\_Image.png][Paste_Image.png]

访问[http://localhost:8881/hi][http_localhost_8881_hi]，浏览器显示：

> foo version 3

本文源码下载：   
[https://github.com/forezp/SpringCloudLearning/tree/master/chapter7][https_github.com_forezp_SpringCloudLearning_tree_master_chapter7]

### 四、参考资料 ###

[spring\_cloud\_config][spring_cloud_config]

[Link 1]: http://blog.csdn.net/forezp/article/details/70037513#
[http_blog.csdn.net_forezp_article_details_70037513]: http://blog.csdn.net/forezp/article/details/70037513
[Link 2]: http://blog.csdn.net/forezp
[Git]: http://lib.csdn.net/base/git
[Link 3]: http://lib.csdn.net/base/microservice
[Link 4]: http://lib.csdn.net/base/architecture
[Azure _3_.png]: /images/20220609/a54f17b19d9a4a928c5f3baf84e9826f.png
[spring]: http://lib.csdn.net/base/javaee
[http_localhost_8889_eureka]: http://localhost:8889/eureka/
[http_localhost_8889]: http://localhost:8889/
[Paste_Image.png]: /images/20220609/069cba08f9aa4f37a718fb295d06b0d5.png
[http_localhost_8881_hi]: http://localhost:8881/hi
[https_github.com_forezp_SpringCloudLearning_tree_master_chapter7]: https://github.com/forezp/SpringCloudLearning/tree/master/chapter7
[spring_cloud_config]: http://projects.spring.io/spring-cloud/spring-cloud.html#_spring_cloud_config