SpringCloud-分布式配置中心(config)

简介

在分布式文件系统中，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，一个是config server， 而是config client。

项目构建

创建一个springboot项目，取名为config-server

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>config-server-desc</description>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.13.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>
<spring-cloud.version>Edgware.SR3</spring-cloud.version>
</properties>

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

<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</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>

</project>

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

@EnableConfigServer
@SpringBootApplication
public class ConfigServerApplication {

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

程序的配置文件application.yml文件配置如下

server:
port:
8888
spring:
application:
name:
config-server
cloud:
config:
server:
git:
uri: https://github.com/EnzoFeng/SpringCloudConfig.git
search-paths: respo
username: EnzoFeng
password: *******
label: master

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

在git新加一个配置文件内容如下

foo=foo version 3

启动程序，访问http://localhost:8888/foo/dev

{"name":"foo","profiles":["dev"],"label":null,"version":"7e84320106fd4750fa1079934ee6cb88d46e9eb0","state":null,"propertySources":[]}

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

构建一个config client

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-client</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>config-client</name>
<description>config-client-desc</description>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.13.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>
<spring-cloud.version>Edgware.SR3</spring-cloud.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>${spring-cloud.version}</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>

</project>

配置文件如下

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

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 测试环境配置文件
pro 正式环境配置文件
spring.cloud.config.uri=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

@RestController
@SpringBootApplication
public class ConfigClientApplication {

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

@Value("${foo}")
String foo;
@RequestMapping("/hi")
public String hi(){
return foo;
}
}

启动项目，请求http://localhost:8881/hi

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