Spring Cloud實戰(一)-Spring Cloud Config Server

概要

• 什麼是Spring Cloud Config?

• 建立並運行一個Spring Cloud Config Server

• 創建一個Repository

• 建立並運行一個Spring Cloud Config Client

Spring Cloud Config是什麼?

什麼是配置信息?
一個Application中不僅是代碼,還須要鏈接資源和其它應用,常常有不少須要外部設置的項去調整Application行爲,如切換不一樣的數據庫,i18n國際化 等.應用中的會常常見到的xml,properties,yaml等就是配置信息.

常見的實現信息配置的方法:

• 硬編碼(缺點:須要修改代碼,風險大)

• 放在xml等配置文件中,和應用一塊兒打包(缺點:須要從新打包和重啓)

• 文件系統中(缺點:依賴操做系統等)

• 環境變量(缺點:有大量的配置須要人工設置到環境變量中,不便於管理,且依賴平臺)

• 雲端存儲(缺點:與其餘應用耦合)
  Spring Cloud Config 就是雲端存儲配置信息的,它具備中心化,版本控制,支持動態更新,平臺獨立,語言獨立等特性.

Spring Cloud Config的原理如圖所示,真正的數據存在Git等repository中,Config Server去獲取相應的信息,而後開發給Client Application,相互間的通訊基於HTTP,TCP,UDP等協議.

建立並運行一個Spring Cloud Config Server

1.建立一個名爲my-config-server的應用,並添加spring-cloud-starter-parent,spring-cloud-config-server依賴,pom信息具體以下

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>org.springframework.cloud</groupId>
         <artifactId>spring-cloud-starter-parent</artifactId>
        <version>Brixton.SR4</version>
        <relativePath/>
    </parent>

    <groupId>org.mmb.cloud</groupId>
    <artifactId>mmb-config-server</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-config-server</artifactId>
        </dependency>

    </dependencies>


</project>

2.在Application主類上添加@EnableConfigServer註解,具體以下

package config;

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

/**
 * Created by mmb on 2016/7/30.
 */
@EnableConfigServer
@SpringBootApplication
public class MMBConfigServerApplication {
    public static void main(String[] args) {
        SpringApplication.run(MMBConfigServerApplication.class, args);
    }
}

3.去本身的GitHub上建立一個repository命名=MMBConfigData,並建立一個mmb-config-client.yml的配置文件,並添加一個key爲luck-word,value mmb,或者其它任何值.具體以下

---
lucky-word: mmb

4.回本身的工程,設置應用application.yml,配置spring.cloud.config.server.git.uri爲"https://github.com/"YOUR-GITHUB-ID"/"YOUR-REPOSITORY-NAME"",並設置端口server.port爲8001

server:
  port: 8001

spring:
  cloud:
    config:
      server:
        git:
          uri: https://github.com/mumubin/MMBConfigData
          searchPaths: data

5.啓動應用並打開地址http://localhost:8001/mmb-con...將會看到配置好的信息,個人以下

{
    "name": "mmb-config-client",
    "profiles": [
        "default"
    ],
    "label": "master",
    "version": "4d9240f45fecd34136f81683d44c2e144792af86",
    "propertySources": [
        {
            "name": "https://github.com/mumubin/MMBConfigData/data/mmb-config-client.yml",
            "source": {
                "lucky-word": "mmb"
            }
        }
    ]
}

建立並運行一個Spring Cloud Config Client

1.建立一個名爲my-config-client的應用,並添加spring-cloud-starter-parent,spring-cloud-starter-config,spring-boot-starter-web依賴,pom信息具體以下

<?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 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>1.3.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-parent</artifactId>
                <version>Brixton.SR4</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <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>
        <!-- Allow for automatic restarts when classpath contents change. -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>
    </dependencies>

    <groupId>org.mmb.cloud</groupId>
    <artifactId>mmb-config-client</artifactId>
    <version>1.0-SNAPSHOT</version>

</project>

2.建立bootstrap.yml在resource下,並設置spring.application.name,spring.cloud.config.uri,server.port信息,具體以下

spring:
  application:
    name: mmb-config-client
  cloud:
    config:
      uri:  http://localhost:8001

---
server:
  port: 8002

注意這裏是bootstrap.yml而不是appliction.yml,由於bootstrap.yml會在應用啓動以前讀取,而spring.cloud.config.uri會影響應用啓動

3.建立一個Controller

@RestController
    public class LuckyWordController {
 
      @Value("${lucky-word}") String luckyWord;
  
      @RequestMapping("/lucky-word")
      public String showLuckyWord() {
        return "The lucky word is: " + luckyWord;
      }
    }

4.啓動Application,打開http://localhost:8002/lucky-word

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

The lucky word is: mmb

特別感謝 kennyk65
Spring Cloud 中文用戶組 31777218
Spring-Cloud-Config 官方文檔-中文譯本
Spring Cloud Netflix 官網文檔-中文譯本
本文實例github地址 Config Server Config Client