Chapter2 消息总线ConfigClient配置自动刷新

Spring Cloud Bus：

Spring Cloud Bus提供了批量刷新配置的机制，它使用轻量级的消息代理（例如RabbitMQ、Kafka等）连接分布式系统的节点，这样就可以通过Spring Cloud Bus广播配置的变化或者其他的管理指令。使用Spring Cloud Bus后的架构如图所示。

准备工作：

需要安装rabbitMQ，安装rabbitMQ的详情请参考：https://blog.csdn.net/qq_35098526/article/details/80009424这篇文章主要讲Windows下的安装过程。

环境搭建

创建三个模块：

eureka-server eureka服务注册中心

config-server 配置中心服务端

config-client 配置中心客户端

1. eureka-server 模块pom文件配置如下，这里跟第一章节一样，不多说。

<?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.harry</groupId><artifactId>eureka-server</artifactId><version>0.0.1-SNAPSHOT</version><packaging>jar</packaging><name>eureka-server</name><description>EUREKA 服务注册中心</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.M9</spring-cloud.version></properties><dependencies><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. config-server 配置中心服务端pom配置，这里引入了spring-cloud-starter-bus-amqp。

<?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.harry</groupId><artifactId>config-server</artifactId><version>0.0.1-SNAPSHOT</version><packaging>jar</packaging><name>config-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.M9</spring-cloud.version></properties><dependencies><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-netflix-eureka-server</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-config-server</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-bus-amqp</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>

application.yml 配置

eureka:client:serviceUrl:defaultZone: http://localhost:8889/eureka/
spring:application:name: config-servercloud:config:server:git:uri: https://gitee.com/honghh/spring-cloud-config # 配置git仓库地址searchPaths: config-doc # 配置仓库路径
#          username: # 访问git仓库的用户名
#          password: # 访问git仓库的用户密码
#      label: #配置仓库的分支server:port: 8989

在application.yml可以看到引入了git仓库地址，如果仓库是私有的，需要输入访问的账号和密码，这个地址是我自己测试用的，是公开的，可以不输入账号密码。searchPaths:config-doc# 配置仓库路径如果仓库路径是根目录则不需要写这个，如果是多级目录，可以写成A/B/C格式。

2. config-client 配置中心客户端这里需要注意pom文件中引入了spring-cloud-starter-bus-amqp，spring-boot-starter-actuator，spring-retry

<?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.harry</groupId><artifactId>config-client</artifactId><version>0.0.1-SNAPSHOT</version><packaging>jar</packaging><name>config-client</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.M9</spring-cloud.version></properties><dependencies><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-netflix-eureka-server</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-config</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-bus-amqp</artifactId></dependency><dependency><groupId>org.springframework.retry</groupId><artifactId>spring-retry</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</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>

bootstrap.yml 配置

eureka:client:serviceUrl:defaultZone: http://localhost:8889/eureka/server:port: 8881spring:application:name: config-clientcloud:config:label: masterprofile: devdiscovery:enabled: trueservice-id: config-serverrabbitmq:host: localhostport: 5672username: guestpassword: guest#management:
#  security:
#    enabled: false  #spring boot1.5.x 版本配置management:endpoints:web:exposure:include: bus-refresh

这里写入rabbitMQ的配置和management的配置，我们可以看到有一段注释的代码，解析看下面注意有坑①。

启动项目

依次启动eureka-server、confg-cserver,启动两个config-client，端口为：8881

1.访问http://localhost:8881/hi浏览器显示：

2这时我们去代码仓库将config-client-dev.properties下的foo的值改为“foo version 4”，即改变配置文件foo的值。如果是传统的做法，需要重启服务，才能达到配置文件的更新。此时，我们只需要发送post请求：http://localhost:8881/bus/refresh，你会发现config-client会重新读取配置文件。可以看到控制台打印日志如图。注意有坑 ①

3. 再次请求http://localhost:8881/hi

到这里操作就已经完成。接下来我们讲一下遇到的问题

注意有坑

① 上面提到请求 http://localhost:8881/bus/refresh但是你在运行的时候遇到报404的错误

图5.1

图5.2

首先，你要确认是post请求，如图5.1是get请求，是会报404的错误的

但是图5.2中用的是post请求为什么还会报错

这里就是我所说的坑看项目中的pom文件我用的是spring boot 2.0.1.RELEASE版本，查资料看到一篇文章 https://ask.csdn.net/questions/684123

详情如下：

SpringBoot2.0Config客户端自动刷新时没有/bus/refresh端点

Spring Cloud ConfigClient的配置自动刷新

目前的博客和视频都是Spring Boot1.5.x的，安装rabbitmq，导入依赖，配置yml，添加@RefreshScope，启动Config client时日志都会打印出/bus/refresh这个端口，但是到spring boot2.0就不再打印这个端口，也无法访问。即使yml配置暴露actuator的所有端口，也就只有/actuator/refresh这个端口（这个端口是只更新一个的）。

请问Spring boot 2.0如何实现Config Client自动刷新配置

Spring boot 2.0的改动较大，/bus/refresh全部整合到actuador里面了，所以之前1.x的management.security.enabled全部失效，不适用于2.0

适用于2.0的配置是这样的：

 management:endpoints:web:exposure:include: bus-refresh

另外注解

@RefreshScope

需要在配置的页面加上，就是说附带@Value的页面加上此注解

请求刷新的页面由原来1.5.x的localhost:8888/bus/refresh

变成：http://localhost:8888/actuator/bus-refresh

注意：config-server和config-client的配置都得加上

 management:endpoints:web:exposure:include: bus-refresh

所以这就是上面为什么这样改的原因,执行刷新的的请求为：

http://localhost:8881/actuator/bus-refresh

下载地址：

代码我已同步到码云git ：https://gitee.com/honghh/spring-cloud-config