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
pom
<?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>sc-f-chapter6</artifactId>
<version>1.0-SNAPSHOT</version>
<modules>
<module>config-server</module>
<module>config-client</module>
</modules>
<name>sc-f-chapter6</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.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>
<spring-cloud.version>Finchley.RELEASE</spring-cloud.version>
</properties>
<dependencies>
<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>
建立一個spring-boot專案,取名為config-server,其pom.xml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 https://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> <name>config-server</name> <description>Demo project for Spring Boot</description> <parent> <groupId>com.forezp</groupId> <artifactId>sc-f-chapter6</artifactId> <version>1.0-SNAPSHOT</version> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-config-server</artifactId> </dependency> <dependency> <groupId>com.forezp</groupId> <artifactId>sc-f-chapter6</artifactId> <version>1.0-SNAPSHOT</version> </dependency> <dependency> <groupId>com.forezp</groupId> <artifactId>sc-f-chapter6</artifactId> <version>1.0-SNAPSHOT</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
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:
package com.forezp.configserver; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.config.server.EnableConfigServer; @SpringBootApplication @EnableConfigServer public class ConfigServerApplication { public static void main(String[] args) { SpringApplication.run(ConfigServerApplication.class, args); } }
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/CMRcircle/SpringcloudConfig/(這裡換成你自己的倉庫地址)
spring.cloud.config.server.git.searchPaths=respos(你倉庫資料夾)
spring.cloud.config.label=master(你的分支)
spring.cloud.config.server.git.username=你的使用者名稱
spring.cloud.config.server.git.password=你的密碼
- 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
foo = foo version 3
啟動程式:訪問http://localhost:8888/foo/dev
{"name":"foo","profiles":["dev"],"label":null,"version":"cfe66eaea0ad0e7efc39a12669884597d045c796","state":null,"propertySources":[]}
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 https://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> <name>config-client</name> <description>Demo project for Spring Boot</description> <parent> <groupId>com.forezp</groupId> <artifactId>sc-f-chapter6</artifactId> <version>1.0-SNAPSHOT</version> </parent> <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> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
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
- 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:
package com.forezp.configclient; import org.springframework.beans.factory.annotation.Value; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @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; } }
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:
原始碼:https://github.com/CMRcircle/learnspringcloud/tree/master/sc-f-chapter6