史上最簡單的SpringCloud教程 | 第六篇: 分散式配置中心(Spring Cloud Config)SpringCloud詳細教程
阿新 • • 發佈：2020-12-16
一、簡介
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。
二、構建Config Server
建立一個spring-boot專案，取名為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/> <!-- 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-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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在程式的入口Application類加上@EnableConfigServer註解開啟配置伺服器的功能，程式碼如下：
@SpringBootApplication @EnableConfigServer public class ConfigServerApplication { public static void main(String[] args) { SpringApplication.run(ConfigServerApplication.class, args); } }
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需要在程式的配置檔案application.properties檔案配置以下：
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
如果Git倉庫為公開倉庫，可以不填寫使用者名稱和密碼，如果是私有倉庫需要填寫，本例子是公開倉庫，放心使用。
遠端倉庫https://github.com/forezp/SpringcloudConfig/ 中有個檔案config-client-dev.properties檔案中有一個屬性：
foo = foo version 3
啟動程式：訪問http://localhost:8888/foo/dev
{"name":"foo","profiles":["dev"],"label":"master",
"version":"792ffc77c03f4b138d28e89b576900ac5e01a44b","state":null,"propertySources":[]}
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證明配置服務中心可以從遠端程式獲取配置資訊。
http請求地址和資原始檔對映如下:
- /{application}/{profile}[/{label}]
- /{application}-{profile}.yml
- /{label}/{application}-{profile}.yml
- /{application}-{profile}.properties
- /{label}/{application}-{profile}.properties
三、構建一個config client
重新建立一個springboot專案，取名為config-client,其pom檔案：
<?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.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/> <!-- 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>
</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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其配置檔案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:8888/ 指明配置服務中心的網址。
程式的入口類，寫一個API介面“／hi”，返回從配置中心讀取的foo變數的值，程式碼如下：
@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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開啟網址訪問：http://localhost:8881/hi，網頁顯示：
foo version 3
這就說明，config-client從config-server獲取了foo的屬性，而config-server是從git倉庫讀取的,如圖：
本文原始碼下載：
https://github.com/forezp/SpringCloudLearning/tree/master/chapter6