什麼是配置中心？

在分散式系統中，由於服務數量巨多，為了方便服務配置檔案統一管理，實時更新，所以需要分散式配置中心元件。在Spring Cloud中，有分散式配置中心元件spring cloud config ，它支援配置服務放在配置服務的記憶體中（即本地），也支援放在遠端Git倉庫中。在spring cloud config 元件中，分兩個角色，一是config server，二是config client。

建立git地址

1. 使用碼雲建立git地址

2. 上傳配置檔案 

config-client-dev.properties  ---dev環境

userName=soldier_123_willpan

建立config-server專案

<?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</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>2.0.4.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>Finchley.RELEASE</spring-cloud.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>
	</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>
 

application.properties 配置檔案 

spring.application.name=config-server
server.port=8889
eureka.client.service-url.defaultZone=http://localhost:8761/eureka/
spring.cloud.config.server.git.uri=https://gitee.com/soldier_123/SpringCloud-config.git
spring.cloud.config.server.git.searchPaths=/**
spring.cloud.config.label=master
spring.cloud.config.server.git.username=
spring.cloud.config.server.git.password=
 

• spring.cloud.config.server.git.uri：配置git倉庫地址
• spring.cloud.config.server.git.searchPaths：配置倉庫路徑
• spring.cloud.config.label：配置倉庫的分支
• spring.cloud.config.server.git.username：訪問git倉庫的使用者名稱
• spring.cloud.config.server.git.password：訪問git倉庫的使用者密碼

application啟動程式，加上@EnableConfigServer註解

@SpringBootApplication
@EnableConfigServer
public class ConfigServerApplication {

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

{"name":"userName","profiles":["dev"],"label":null,"version":"fd91f3575359d0401461cdc59733af0c6472bd25","state":null,"propertySources":[]}

建立config-client 專案

<?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</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>2.0.4.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>Finchley.RELEASE</spring-cloud.version>
	</properties>

	<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>
	</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>

bootstrap.properties 

spring.application.name=config-client
spring.cloud.config.label=master
spring.cloud.config.profile=dev
spring.cloud.config.uri= http://localhost:8889/
server.port=8881

• spring.cloud.config.label 指明遠端倉庫的分支
• spring.cloud.config.profile
  • dev開發環境配置檔案
  • test測試環境
  • pro正式環境
• spring.cloud.config.uri= http://localhost:8889/ 指明配置服務中心的網址。

application啟動程式 

@SpringBootApplication
@RestController
public class ConfigClientApplication {

	public static void main(String[] args) {
		SpringApplication.run(ConfigClientApplication.class, args);
	}
	@Value("${userName}")
	String userName;

	@RequestMapping("/getUserName")
	public String getUserName() {
		return userName;
	}
}

soldier_123_willpan