springCloud-- 配置中心config

柔情只为你懂 2022-05-28 00:28 196阅读 0赞

### 一、简介 ###

在分布式系统中，由于服务数量巨多，为了方便服务配置文件统一管理，实时更新，所以需要分布式配置中心组件。在Spring Cloud中，有分布式配置中心组件spring cloud config ，它支持配置服务放在配置服务的内存中（即本地），也支持放在远程Git仓库中。在spring cloud config 组件中，分两个角色，一是config server，二是config client。

### 二、构建Config Server ###

创建一个spring-boot项目，取名为config-server,其pom.xml:

<?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>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>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-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>
    
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies</artifactId>
                    <version>Camden.SR6</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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在程序的入口Application类加上@EnableConfigServer注解开启配置服务器的功能，代码如下：

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

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需要在程序的配置文件application.properties文件配置以下：

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

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*  spring.cloud.config.server.git.uri：配置git仓库地址
 *  spring.cloud.config.server.git.searchPaths：配置仓库路径
 *  spring.cloud.config.label：配置仓库的分支
 *  spring.cloud.config.server.git.username：访问git仓库的用户名
 *  spring.cloud.config.server.git.password：访问git仓库的用户密码

如果Git仓库为公开仓库，可以不填写用户名和密码，如果是私有仓库需要填写，本例子是公开仓库，放心使用。

远程仓库[https://github.com/forezp/SpringcloudConfig/][https_github.com_forezp_SpringcloudConfig] 中有个文件config-client-dev.properties文件中有一个属性：

> foo = foo version 3

启动程序：访问[http://localhost:8888/foo/dev][http_localhost_8888_foo_dev]

{"name":"foo","profiles":["dev"],"label":"master",
    "version":"792ffc77c03f4b138d28e89b576900ac5e01a44b","state":null,"propertySources":[]}

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证明配置服务中心可以从远程程序获取配置信息。

http请求地址和资源文件映射如下:

*  /\{application\}/\{profile\}\[/\{label\}\]
 *  /\{application\}-\{profile\}.yml
 *  /\{label\}/\{application\}-\{profile\}.yml
 *  /\{application\}-\{profile\}.properties
 *  /\{label\}/\{application\}-\{profile\}.properties

### 三、构建一个config client ###

重新创建一个springboot项目，取名为config-client,其pom文件：

<?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>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>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-config</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>

其配置文件**bootstrap.properties**：

spring.application.name=config-client
    spring.cloud.config.label=master
    spring.cloud.config.profile=dev
    spring.cloud.config.uri= http://localhost:8888/
    server.port=8881

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*  spring.cloud.config.label 指明远程仓库的分支
 *  spring.cloud.config.profile
    
     *  dev开发环境配置文件
     *  test测试环境
     *  pro正式环境
 *  spring.cloud.config.uri= [http://localhost:8888/][http_localhost_8888] 指明配置服务中心的网址。

程序的入口类，写一个API接口“／hi”，返回从配置中心读取的foo变量的值，代码如下：

@SpringBootApplication
    @RestController
    public class ConfigClientApplication { 
    
        public static void main(String[] args) {
            SpringApplication.run(ConfigClientApplication.class, args);
        }
    
        @Value("${foo}")
        String foo;
        @RequestMapping(value = "/hi")
        public String hi(){
            return foo;
        }
    }

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打开网址访问：[http://localhost:8881/hi][http_localhost_8881_hi]，网页显示：

> foo version 3

这就说明，config-client从config-server获取了foo的属性，而config-server是从git仓库读取的,如图：

![Azure (2).png][Azure _2_.png]

本文源码下载：  
[https://github.com/forezp/SpringCloudLearning/tree/master/chapter6][https_github.com_forezp_SpringCloudLearning_tree_master_chapter6]

### 四、参考资料 ###

[spring\_cloud\_config][spring_cloud_config]

[https_github.com_forezp_SpringcloudConfig]: https://github.com/forezp/SpringcloudConfig/
[http_localhost_8888_foo_dev]: http://localhost:8888/foo/dev
[http_localhost_8888]: http://localhost:8888/
[http_localhost_8881_hi]: http://localhost:8881/hi
[Azure _2_.png]: /images/20220528/3f0a70c4fbde41309cd9fc9038260ddf.png
[https_github.com_forezp_SpringCloudLearning_tree_master_chapter6]: https://github.com/forezp/SpringCloudLearning/tree/master/chapter6
[spring_cloud_config]: http://projects.spring.io/spring-cloud/spring-cloud.html#_spring_cloud_config