转载

Springcloud教程六：分布式配置中心

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。

1：新建一个工程，命名为config-server,同意idea支持创建该类工程

pom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.springcloud</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/> <!-- lookup parent from repository -->
    </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.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>


        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-config-server</artifactId>
           <!-- <version>1.4.0.RELEASE</version>-->
        </dependency>
        <dependency>
            <groupId>org.eclipse.jgit</groupId>
            <artifactId>org.eclipse.jgit</artifactId>
            <version>4.8.0.201706111038-r</version>
        </dependency>

    </dependencies>

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

    <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>

    <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>

注意，自动新建完的工程中的版本可能会比较高，我们需要手动改成 1.5.2.RELEASE，这样才能保证下面的操作可用。

启动类加入注解，如下：

@SpringBootApplication
@EnableConfigServer
public class ConfigServerApplication {

    public static void main(String[] args) {

        SpringApplication.run(ConfigServerApplication.class, args);
    }
}

修改配置文件，如下：

spring.application.name=config-server
server.port=8888


#配置文件在本地
#spring.profiles.active=native
#配置文件的目录
#spring.cloud.config.server.native.search-locations=D:/workspace/GitHub/spring-config/config-file

#spring.cloud.config.server.git.uri=https://github.com/forezp/SpringcloudConfig/
spring.cloud.config.server.git.uri=https://github.com/iot-wangshuyu/springcloud
#配置仓库路径
spring.cloud.config.server.git.searchPaths=SpringcloudConfig/respo/
#配置仓库的分支
spring.cloud.config.label=master
#访问git仓库的用户名,仓库为public则不用填写
spring.cloud.config.server.git.username=
#访问git仓库的用户密码
spring.cloud.config.server.git.password=

如果想使用git仓库就把本地配置注释掉，如果想使用本地配置，就把git仓库注释掉，然后再本地对应目录下新建一个config-client-dev.properties文件，内容为：

foo = foo version 2

我使用的是git远程仓库。

配置完成后启动程序，访问 http://localhost:8888/config-client/dev/

{“name”:”config-client”,”profiles”:[“dev”],”label”:”master”,”version”:”3205652bcac310656b2f00790e7130e7df19a64e”,”state”:null,”propertySources”:[{“name”:” https://github.com/iot-wangshuyu/springcloud/SpringcloudConfig/respo/config-client-dev.properties “,”source”:{“foo”:”foo version 2”}}]}

返回以上结果，说明配置成功了。

2：构建config client

新建一个config client工程，命名为config-client，pom配置如下：

<?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.springcloud</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/> <!-- lookup parent from repository -->
    </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>

        </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>

配置文件如下：

#服务名称
spring.application.name=config-client
#仓库分支
spring.cloud.config.label=master
#dev开发环境配置文件
#test测试环境
#pro正式环境
spring.cloud.config.profile=dev
#使用eureka server的时候需要注释掉
spring.cloud.config.uri= http://localhost:8888/

在程序中写一个API接口，返回从配置文件中读取的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;
    }
}

在浏览器中访问： http://localhost:8881/hi

foo version 2

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： Springcloud教程六：分布式配置中心