Spring Cloud Config 高可用分布式配置中心

1.介绍

上篇文章讲了 Spring Cloud 配置中心 : 配置中心从远程git仓库获取配置文件信息； 服务从配置中心读取配置信息，将结合 Eureka服务注册中心 组成高可用服务配置中心，当服务实例很多时，配置中心达到高可用。

2.使用

继续使用上一篇文章的工程

1）创建服务注册中心

①先创建一个Spring Boot 工程 eureka-server，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>

	<groupId>com.xeepoo</groupId>
	<artifactId>eureka-server</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

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

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.1.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>Finchley.RC1</spring-cloud.version>
	</properties>

	<dependencies>
		<!-- eureka server-->
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-netflix-eureka-server</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>

②在 启动类EurekaServerApplication  添加注解 @EnableEurekaServer

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

③配置文件 application.yml

####注册中心端口号
server:
  port: 8900
#### 通过 eureka.client.register-with-eureka false
#### 和 etch-registry:false来表明这是个eureka server.
eureka:
####主机名
  instance:
    hostname: localhost
  client:
    service-url:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/
    register-with-eureka: false
    fetch-registry: false

④启动程序，访问 http://localhost:8900/ 看到下面界面表示成功

2）改造config-server 

①在pom.xml中添加依赖

		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
		</dependency>

② 配置文件 application.yml

#端口号
server:
  port: 8880
spring:
  application:
    #服务名称
    name: config-server
  cloud:
    config:
      server:
        #git地址
        git:
          uri: https://gitee.com/XeePoo/config-server.git
          search-paths: respo
          username: *****
          password: *****
#eureka注册中心地址
eureka:
  client:
    service-url:
      defaultZone: http://localhost:8900/eureka/

通过配置 eureka.client.service-url.default配置中心会向eureka注册中心 注册服务 名称为 spring.application.name的服务

(注: 在配置中指定了eureka注册中心地址,就不需要在启动类添加注解@EnableEurekaClient ，（添加了也可以，更易读） )

③启动 config-server,继续访问注册中心  http://localhost:8900/

可以看到 config-server已经成功的注册到了服务注册中心

④先 关闭  config-server 服务

3）改造config-client

①在pom.xml文件中 添加依赖 

<!-- 服务注册 eureka client -->
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
		</dependency>

②配置文件 bootstrap.yml

server:
  port: 8882
spring:
  application:
    name: config-client
  cloud:
    config:
      profile: dev
      label: master
      fail-fast: true #没有启动configserver 会快速报错停止
      discovery:
        service-id: config-server
        enabled: true 
#eureka注册中心地址
eureka:
  client:
    service-url:
      defaultZone: http://localhost:8900/eureka/

注意:这里不再使用spring.cloud.config.uri方式指明使用配置中心地址访问,而是使用 spring.cloud.config.discovery.service-id 既 配置中心config-server在 注册中心 注册的名称 方式访问注册中心获取配置,

同时指明注册中心地址

4) 新建一个Spring Boot项目命名为 config-client2

在配置中心配置的git仓库中添加配置文件 config-client2-dev.properties 内有属性 test2=Config-Client2

test2=Config-Client2

①config-client2的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.xeepoo</groupId>
	<artifactId>config-client2</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>config-client2</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.2.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>Finchley.RC1</spring-cloud.version>
	</properties>

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

②创建一个Controller 命名为 TestController

@RestController
public class TestController {
    
    @Value("${test}")
    String test;
    
    @RequestMapping("hello3")
    public String test2(){
        return "test2 "+test;
    }
}

③配置文件 bootstrap.yml

server:  
  port: 8883  
spring:  
  application:  
    name: config-client2  
  cloud:  
    config:  
      profile: dev  
      label: master  
      fail-fast: true #没有发现 Config Server 服务 会快速报错停止  
      discovery:  
        service-id: config-server  
        enabled: true  
#eureka注册中心地址  
eureka:  
  client:  
    service-url:  
      defaultZone: http://localhost:8900/eureka/  

5)使用服务 

①停止所有服务,启动eureka-server

②config-server启动，然后修改config-server的application.yml端口 8881再次启动

    共启动两次，端口号为8880和8881

③config-client、config-client2分别启动

④访问 http://localhost:8900/ 可以看到

⑤访问地址

    http://localhost:8881/hello1 

        hello1 Spring Cloud Config

   http://localhost:8882/hello3

         test2 Config-Client2