【SpringCloud】第六篇: 分布式配置中心(Spring Cloud Config)

前言:

必需学会SpringBoot基础知识

简介:

spring cloud 为开发人员提供了快速构建分布式系统的一些工具，包括配置管理、服务发现、断路器、路由、微代理、事件总线、全局锁、决策竞选、分布式会话等等。它运行环境简单，可以在开发人员的电脑上跑。

工具:

JDK8

apache-maven-3.5.2

IntelliJ IDEA 2018.1 x64

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eureka-config-server，二是eureka-config-client。

二、构建 eureka-config-server

(1) 创建springboot项目, 命名: eureka-config-server

(2) 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.lwc</groupId>
    <artifactId>eureka-config-server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>eureka-config-server</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.10.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.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>${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>

(3) 启动类: 添加注解 @EnableConfigServer

package com.lwc;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.config.server.EnableConfigServer;

/**
 * @author Eddie
 */
@EnableConfigServer
@SpringBootApplication
public class EurekaConfigServerApplication {

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

(4) application.yml 和 说明

application.yml	application-dev.yml
spring: application: name: eureka-config-server profiles: active: ${@profileActiv@:dev}	server: port: 8888 eureka: client: serviceUrl: defaultZone: http://localhost:8761/eureka/ spring: cloud: config: server: git: uri: https://github.com/eddie-code/SpringCloudDemo search-paths: config-repo username: passphrase: 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 (公共库可无视)

spring.cloud.config.server.git.password：访问git仓库的用户密码 (公共库可无视)

里面存在一个config-repo目录, 里面几个app*配置文件 (为方便大家,可使用本人提供的)

启动项目, 访问: http://localhost:8888/app/local/master

{
     "name": "app",
     "profiles": ["local"],
     "label": "master",
     "version": "e366cdb9f58c68216631b39432dbbaba7ad70809",
     "state": null,
     "propertySources": [{
         "name": "https://github.com/eddie-code/SpringCloudDemo/config-repo/app-local.properties",
         "source": {
             "eddie": "local config"
         }
     },
     {
         "name": "https://github.com/eddie-code/SpringCloudDemo/config-repo/app.properties",
         "source": {
             "eddie": "default config"
         }
     }]
}

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 eureka-config-client

(1) 创建springboot项目, 命名: eureka-config-client

(2) 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.lwc</groupId>
    <artifactId>eureka-config-client</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>eureka-config-client</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.10.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>

    <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>

(3) 新建配置文件命名: bootstrap-*.yml 

(local=本地测试, dev=开发环境, pro=正式环境)

(spring.cloud.config.label=指明远程仓库的分支, spring.cloud.config.uri=配置服务中心的网址)

bootstrap.yml	bootstrap-dev.yml  (其余自己新建)
spring: application: name: eureka-config-client profiles: active: ${@profileActiv@:local}	server: port: 8881 eureka: client: serviceUrl: defaultZone: http://localhost:8761/eureka/ register-with-eureka: false fetch-registry: false spring: cloud: config: profile: dev label: master uri: http://localhost:8888/

(4) 控制层相关代码

package com.lwc;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

/**
 * @author Eddie
 */
@SpringBootApplication
public class EurekaConfigClientApplication {

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

package com.lwc.controller;

import com.lwc.dto.GitDto;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author eddie.lee
 * @Package com.lwc.controller
 * @ClassName AppController
 * @description 获取配置中心属性
 * @date created in 2018-04-03 14:22
 * @modified by
 */
@RestController
public class AppController {

    @Autowired
    private GitDto gitDto;

    @Value("${eddie}")
    private String eddie;

    @Value("${url}")
    private String url;

    @GetMapping("/url")
    public String url() {
        return this.url;
    }

    @GetMapping("/eddie")
    public String eddie() {
        return this.eddie;
    }

    @GetMapping("/configs")
    public String configs() {
        return "This is " + gitDto.getEddie() + " Blog: " + gitDto.getUrl();
    }

}

(5) 测试

访问: http://localhost:8881/configs

This is local config Blog: http://www.cnblogs.com/EddieBlog/

(6) 图解

四、源码下载

标签 6-1, 6-2

https://github.com/eddie-code/SpringCloudDemo/tree/master/eureka-config-server

https://github.com/eddie-code/SpringCloudDemo/tree/master/eureka-config-client

五、踩过的坑

源码有记录