在上一篇文章讲述zuul的时候,已经提到过,使用配置服务来保存各个服务的配置文件。它就是Spring Cloud Config。
一、简介
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。
二、构建Config Server
创建一个spring-boot项目,取名为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>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.5.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>config-server</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>config-server</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Greenwich.SR1</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-netflix-eureka-client</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:
package com.example.configserver;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.config.server.EnableConfigServer;
@EnableConfigServer
@SpringBootApplication
public class ConfigServerApplication {
public static void main(String[] args) {
SpringApplication.run(ConfigServerApplication.class, args);
}
}
需要在程序的配置文件application.properties文件配置以下:
如果是私有的库要修改 username 跟 password,如果是公开的就随便写
spring:
application:
name: config-server
cloud:
config:
server:
git:
uri: https://github.com/chanxinguidao/SpringCloudConfig/
search-paths: config
username: hello
password: hello
label: master
server:
port: 8888
- 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仓库的用户密码
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,本例子是公开仓库,放心使用。
远程仓库https://github.com/chanxinguidao/SpringCloudConfig/ 中有个文件config-client-dev.properties文件中有一个属性:
version=V0.1
启动程序:访问http://localhost:8888/test/dev (这个只是测试用随便写)
{"name":"test","profiles":["dev"],"label":"master",
"version":"34523ab3b53f4b138d28e89b576900ac5e014667","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
三、构建一个config client
重新创建一个springboot项目,取名为config-client,其pom文件:
<?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>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.5.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>config-client</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>config-client</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Greenwich.SR1</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>
其配置文件:
配置中心的服务端默认是8888端口,如果没有改优先级不要改这个端口哦,老鸟绕路:
spring:
cloud:
config:
label: master
profile: dev
uri: http://localhost:8888/
application:
name: config-client
- 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
- pro正式环境
- 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:
package com.example.configclient;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
* 偷懒直接当controller了
*/
@RestController
@SpringBootApplication
public class ConfigClientApplication {
public static void main(String[] args) {
SpringApplication.run(ConfigClientApplication.class, args);
}
@Value("${version}")
String version;
@GetMapping(value = "/hi")
public String hi(){
return version;
}
}
打开网址访问:http://localhost:8080/hi,网页显示:
V0.1
这就说明,config-client从config-server获取了version的属性,而config-server是从git仓库读取的,如图:
graph LR
git --获取配置--> config-server
config-server --读取配置--> config-client
本文源码下载:https://github.com/chanxinguidao/SpringCloudLearning/tree/master/chapter6