Spring Cloud Config 配置Client讀取不到server配置文件

學習Spring Cloud Config 的時候，很容易遇到各種各樣的問題，這里我就把我遇到的：Client 端讀取不到Server端的配置文件中的屬性總結一下。

首先我搭建了一個Eureka 注冊中心，這里就不著重介紹了，不知道的小伙伴可以
網上查資料！

1.搭建Config 配置中心

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>2.1.7.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.sg.config</groupId>
    <artifactId>config-demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>config-demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.SR2</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>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</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>

這里面Config用到的依賴是 spring-cloud-config-server ，其他自己看著引入即可

2.application.yml 的配置

server:
  port: 8095
spring:
  application:
    name: config-demo
  cloud:
    config:
      server:
        git:
          uri: https://github.com/****/spring-cloud-demo.git
          username:
          password: 
          search-paths: spring-cloud-demo-config
eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:8090/eureka/
    register-with-eureka: true
    fetch-registry: true

Config Server 的配置主要是spring.cloud.config.server.git 下面的東西，其他按需配置即可。

3.Config Server 啟動類

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

@SpringBootApplication
@EnableConfigServer
@EnableDiscoveryClient
public class ConfigDemoApplication {

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

}

至此 Config Server 端就配置完成了。

4.配置Config Client 端

首先引入依賴

<?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>2.1.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.sg.eureka.client</groupId>
    <artifactId>eureka-client-demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>eureka-client-demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.SR2</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-netflix-eureka-client</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.sg.common</groupId>
            <artifactId>spring-cloud-common</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-config -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</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>

主要有關的依賴是 spring-cloud-starter-config ，其他的按需引入即可

5.application.yml 配置文件

server:
  port: 8091
spring:
  application:
    name: eureka-client-demo
  cloud:
    config:
      profile: test
      uri: http://127.0.0.1:8095/
      label: master
      discovery:
        enabled: true
        service-id: config-demo

eureka:
  client:
    register-with-eureka: true
    fetch-registry: true
    service-url:
      defaultZone: http://127.0.0.1:8090/eureka/

### 端點控制
management:
  endpoints:
    web:
      exposure:
        # 開啟指定端點
        include: hystrix.stream

project:
  name: hahha

啟動類上什么配置也不用添加，就可以了，重要的一點：
1：如果用了Eureka ，則需要配置 spring.cloud.config.discovery.enable: true 和 spring.cloud.config.discovery.service-id: config-demo 這兩個屬性

6.讀取Server中配置的屬性 

package com.sg.eureka.client.controller;

import com.sg.common.vo.UserVO;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;
import org.springframework.web.bind.annotation.*;

/**
 * @author liuhailong
 * @date 2019-08-08
 */
@RestController
@RequestMapping(value = "users")
@Configuration
public class UserController {

    @Autowired
    private Environment environment;

    @Value("${project.name}")
    private String name;

    @GetMapping(value = "/config")
    public String getConfig(@RequestParam("key")String key){
        return environment.getProperty(key);
    }

    @GetMapping(value = "/projectName")
    public String projectName(){
        return name;
    }

}

我這里用了 兩種方式去讀取配置文件中的內容
1：使用Spring core中的Environment 類 中的getProperty 可以取到
2：使用Spring 的 @Value("${project.name}") 注解

6.接下來驗證一下：訪問 http://localhost:8091/users/config?key=project.name 結果發現獲取不到Config Server中配置的參數。

主要原因：

Spring Cloud 會首先加載bootstrap.yml 和bootstrap.properties 配置文件，然后再去加載spplication.properties 配置文件，所以在Config client 中的配置文件名稱要修改為 bootstrap.yml 。然后在讀取配置中心Config Server 中的 eureka-client-demo-test 的配置文件，這樣就可以讀取到了。