Spring Cloud外部环境配置刷新
本文介绍在spring cloud架构中，如何做配置外部化以及更改配置属性并实时刷新的问题。
实验环境：
spring boot：2.1.4.RELEASE
spring cloud: Greenwich.SR1
github
rabbitmq: 3.7.8
服务注册发现中心eureka-server
关键依赖：
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>
application.yml：
server:
port: 1112
spring:
application:
name: eureka-server
profiles:
active: dev
logging:
level:
com:
netflix:
eureka: off
discovery: off
file: logs/${spring.application.name}.log
application-dev.yml：
eureka:
instance:
instance-id: ${spring.application.name}:${spring.cloud.client.ip_address}:${server.port}
hostname: localhost
client:
fetch-registry: false
register-with-eureka: false #不注册自己
service-url:
defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/
server:
enable-self-preservation: false #设为false，关闭自我保护
eviction-interval-timer-in-ms: 4000 # 清理间隔（单位毫秒，默认是60*1000）
该服务没什么需要注意的，按正常的来就可以。
配置中心config-server
关键依赖：
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-server</artifactId>
</dependency>
<!--实时刷新配置 start -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-monitor</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-bus-amqp</artifactId>
</dependency>
<!--实时刷新配置 end -->
<!--作为服务注册到服务注册中心 -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
要配置刷新，只需要添加：
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-config-monitor</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-bus-amqp</artifactId>
</dependency>
配置
bootstrap.yml：
server:
port: 3331
spring:
application:
name: config-server
profiles:
active: dev
## 非对称加解密,该段配置只能放在bootstrap.yml中
encrypt:
key-store:
location: classpath:/config-server.jks
password: 111111 # storepass
alias: config-server # alias
secret: 222222 # keypass
application.yml：
management:
endpoints:
web:
exposure:
include: "*"
management.endpoints.web.exposure.include这个配置一定要加上，关键。默认是指暴露站点：info，health。改成星号，代表暴露全部。
application-dev.yml：
#作为服务注册到注册中心
eureka:
server:
ip: localhost
port: 1112
instance:
instance-id: ${spring.application.name}:${spring.cloud.client.ip-address}:${server.port}
prefer-ip-address: true #显示ip,浏览器以ip方式请求。
#域名
# hostname: localhost
#查看健康运行状态
health-check-url-path: /actuator/health
status-page-url-path: /actuator/info
client:
service-url:
defaultZone: http://${eureka.server.ip}:${eureka.server.port}/eureka/
spring:
security:
user:
name: admin
password: 123456
cloud:
#git配置中心
config:
server:
git:
uri: https://github.com/xrlj/config-repo-dev
#git的配置文件会加载到本地的目录
basedir: target/config
# 设置超时
timeout: 4
force-pull: true #每次都强制拉取远程git的配置更新本地。
default-label: master
bus:
enabled: true
trace:
enabled: true
# search-paths:
# spring-cloud-bus刷新配置
#http://localhost:15672/
rabbitmq:
host: 172.31.31.31
port: 5672
username: admin
password: 123456
publisher-confirms: true
virtual-host: xr_vhost
encrypt:
fail-on-error: false
注意开启：spring.cloud.bus.enable=true,spring.cloud.bus.trace.enable=true。
温馨提醒
由于添加了安全依赖：
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
所以config-server的请求是要先登陆验证的。那么，就要要配置spring-security，否则后面的post请求将会被拒绝。添加配置类如下：
package com.xrlj.configserver;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
@Configuration
@EnableWebSecurity
public class WebSecurityConfiguration extends WebSecurityConfigurerAdapter {
@Override
protected void configure(HttpSecurity http) throws Exception {
http.csrf().disable().authorizeRequests()
.anyRequest().authenticated().and()
.httpBasic();
}
}
其它业务服务service-sys-common
添加与配置刷新相关依赖：
<!-- 用户修改git文件，调用接口自动刷新： -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<!--rabbitmq实时刷新配置-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-bus-amqp</artifactId>
</dependency>
关键配置：
spring:
cloud:
bus:
enabled: true
trace:
enabled: true
# refresh:
# extra-refreshable: javax.sql.DataSource #该版本中，默认数据源是HikariDataSource，不配置这个，刷新配置报错。
management:
endpoints:
web:
exposure:
include: "*"
和config-server中一样，星号暴露所有站点，还要bus的一些配置开启。这里有个不同点，spring.cloud.refresh.extra-refreshable=javax.sql.DataSource,这里先注释掉，后面再补充说明下。
验证配置刷新
1.在service-sys-common服务中新建TestController.java
@RefreshScope
@RestController
public class TestController {
@Value("${foo}")
String foo;
@RequestMapping(value = "/hi")
public String hi(){
return foo;
}
}
注意添加注解@RefreshScope。在配置仓库中对应文件添加属性foo:version1。
打开浏览器请求：http://localhost:9010/hi.正常会返回`foo`的值。
更改foo的值，foo:version2,再次请求，看到返回还是version1，证明没刷新。下面刷新下，打开postman发送post刷新请求：localhost:9010/actuator/refresh
然后我们会看到一个错误：
2018-02-04 22:11:02.236 DEBUG 6104 --- [ main] o.s.b.d.LoggingFailureAnalysisReporter : Application failed to start due to an exception
org.springframework.boot.context.properties.bind.BindException: Failed to bind properties under 'spring.datasource.hikari' to com.zaxxer.hikari.HikariDataSource
at org.springframework.boot.context.properties.bind.Binder.handleBindError(Binder.java:227) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:203) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:187) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:169) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.context.properties.ConfigurationPropertiesBinder.bind(ConfigurationPropertiesBinder.java:79) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor.postProcessBeforeInitialization(ConfigurationPropertiesBindingPostProcessor.java:167) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:423) ~[spring-beans-5.0.3.RELEASE.jar:5.0.3.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1702) ~[spring-beans-5.0.3.RELEASE.jar:5.0.3.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:414) ~[spring-beans-5.0.3.RELEASE.jar:5.0.3.RELEASE]
at org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder.rebind(ConfigurationPropertiesRebinder.java:101) ~[spring-cloud-context-2.0.0.M5.jar:2.0.0.M5]
at org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder.rebind(ConfigurationPropertiesRebinder.java:84) ~[spring-cloud-context-2.0.0.M5.jar:2.0.0.M5]
at org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder.onApplicationEvent(ConfigurationPropertiesRebinder.java:132) ~[spring-cloud-context-2.0.0.M5.jar:2.0.0.M5]
at org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder.onApplicationEvent(ConfigurationPropertiesRebinder.java:50) ~[spring-cloud-context-2.0.0.M5.jar:2.0.0.M5]
at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) ~[spring-context-5.0.3.RELEASE.jar:5.0.3.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) ~[spring-context-5.0.3.RELEASE.jar:5.0.3.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) ~[spring-context-5.0.3.RELEASE.jar:5.0.3.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:399) ~[spring-context-5.0.3.RELEASE.jar:5.0.3.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:353) ~[spring-context-5.0.3.RELEASE.jar:5.0.3.RELEASE]
at org.springframework.cloud.autoconfigure.ConfigurationPropertiesRebinderAutoConfiguration.afterSingletonsInstantiated(ConfigurationPropertiesRebinderAutoConfiguration.java:77) ~[spring-cloud-context-2.0.0.M5.jar:2.0.0.M5]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:778) ~[spring-beans-5.0.3.RELEASE.jar:5.0.3.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868) ~[spring-context-5.0.3.RELEASE.jar:5.0.3.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.0.3.RELEASE.jar:5.0.3.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:138) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:752) [spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:388) [spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1246) [spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1234) [spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at uk.co.vhome.clubbed.svc.enquiryhandler.ClubbedSvcEnquiryHandlerApplication.main(ClubbedSvcEnquiryHandlerApplication.java:23) [classes/:na]
Caused by: java.lang.IllegalStateException: Unable to set value for property schema
at org.springframework.boot.context.properties.bind.JavaBeanBinder$BeanProperty.setValue(JavaBeanBinder.java:306) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.context.properties.bind.JavaBeanBinder.bind(JavaBeanBinder.java:76) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.context.properties.bind.JavaBeanBinder.bind(JavaBeanBinder.java:59) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.context.properties.bind.JavaBeanBinder.bind(JavaBeanBinder.java:51) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.context.properties.bind.Binder.lambda$null$5(Binder.java:321) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195) ~[na:na]
at java.base/java.util.ArrayList$ArrayListSpliterator.tryAdvance(ArrayList.java:1471) ~[na:na]
at java.base/java.util.stream.ReferencePipeline.forEachWithCancel(ReferencePipeline.java:127) ~[na:na]
at java.base/java.util.stream.AbstractPipeline.copyIntoWithCancel(AbstractPipeline.java:502) ~[na:na]
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:488) ~[na:na]
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474) ~[na:na]
at java.base/java.util.stream.FindOps$FindOp.evaluateSequential(FindOps.java:152) ~[na:na]
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:na]
at java.base/java.util.stream.ReferencePipeline.findFirst(ReferencePipeline.java:476) ~[na:na]
at org.springframework.boot.context.properties.bind.Binder.lambda$bindBean$6(Binder.java:322) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.context.properties.bind.Binder$Context.withIncreasedDepth(Binder.java:415) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.context.properties.bind.Binder$Context.withBean(Binder.java:405) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.context.properties.bind.Binder.bindBean(Binder.java:319) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.context.properties.bind.Binder.bindObject(Binder.java:261) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:198) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
... 27 common frames omitted
Caused by: java.lang.reflect.InvocationTargetException: null
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:564) ~[na:na]
at org.springframework.boot.context.properties.bind.JavaBeanBinder$BeanProperty.setValue(JavaBeanBinder.java:303) ~[spring-boot-2.0.0.RC1.jar:2.0.0.RC1]
... 46 common frames omitted
Caused by: java.lang.IllegalStateException: The configuration of the pool is sealed once started. Use HikariConfigMXBean for runtime changes.
at com.zaxxer.hikari.HikariConfig.setSchema(HikariConfig.java:951) ~[HikariCP-2.7.6.jar:na]
... 51 common frames omitted
2018-02-04 22:11:02.237 ERROR 6104 --- [ main] o.s.b.d.LoggingFailureAnalysisReporter :
***************************
APPLICATION FAILED TO START
***************************
Description:
Failed to bind properties under 'spring.datasource.hikari' to com.zaxxer.hikari.HikariDataSource:
Property: spring.datasource.hikari.schema
Value: ${application.database.schema}
Origin: class path resource [application.properties]:11:33
Reason: Unable to set value for property schema
Action:
Update your application's configuration
Process finished with exit code 1
爆出该异常源码地方：类ConfigurationPropertiesRebinder
@ManagedOperation
public boolean rebind(String name) {
if (!this.beans.getBeanNames().contains(name)) {
return false;
}
if (this.applicationContext != null) {
try {
Object bean = this.applicationContext.getBean(name);
if (AopUtils.isAopProxy(bean)) {
bean = ProxyUtils.getTargetObject(bean);
}
if (bean != null) {
this.applicationContext.getAutowireCapableBeanFactory()
.destroyBean(bean);
this.applicationContext.getAutowireCapableBeanFactory()
.initializeBean(bean, name);
return true;
}
}
catch (RuntimeException e) {
this.errors.put(name, e);
throw e;
}
catch (Exception e) {
this.errors.put(name, e);
throw new IllegalStateException("Cannot rebind to " + name, e);
}
}
return false;
}
问题原因：
那是因为，我们在项目里自定义了动态数据源，采用了默认的数据库连接池HikariDataSource，该连接池，一旦创建，讲不可更改，所以当你刷新配置的时候，是一起连同数据源的相关配置也要刷新的，所以报错了。
数据源配置如下：
package com.xrlj.framework.spring.config.ds.myself;
import com.xrlj.framework.dao.ds.DynamicDataSource;
import com.zaxxer.hikari.HikariDataSource;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.*;
/**
* 按规则定死的数据源。一主双从。适用所有服务。
*/
@Configuration
public class DataSourceConfig {
@Bean(name = "masterDataSource")
@Qualifier("masterDataSource")
@ConfigurationProperties(prefix="spring.myself-db.datasource.hikari.master")
public DataSource masterDataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
@Bean(name = "slave1DataSource")
@Qualifier("slave1DataSource")
@ConfigurationProperties(prefix="spring.myself-db.datasource.hikari.slave1")
public DataSource slave1DataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
@Bean(name = "slave2DataSource")
@Qualifier("slave2DataSource")
@ConfigurationProperties(prefix="spring.myself-db.datasource.hikari.slave2")
public DataSource slave2DataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
/**
* 动态数据源: 通过AOP在不同数据源之间动态切换
*
* @return
*/
@Primary
@Bean(name = "dynamicDataSource")
@Qualifier("dynamicDataSource")
@Scope("singleton")
@DependsOn({"masterDataSource","slave1DataSource","slave2DataSource"}) //要加入这个注解，在数据源初始化之后，再初始化本bean，否则会出现循环依赖注入无法启动。
public DataSource dynamicDataSource(@Qualifier("masterDataSource") DataSource masterDataSource,
@Qualifier("slave1DataSource") DataSource slave1DataSource,@Qualifier("slave2DataSource") DataSource slave2DataSource) {
DynamicDataSource dynamicDataSource = new DynamicDataSource();
return dynamicDataSource.setMultipleDataSource(masterDataSource,slave1DataSource,slave2DataSource);
}
}
折腾了半天，终于在官网wiki中找到答案。
参考：
https://github.com/spring-cloud/spring-cloud-commons/pull/395
https://github.com/spring-cloud/spring-cloud-commons/issues/318
其中有一段问题解决的描述如下：
After trying to implement this, we are going to add a documentation note, but you should either set spring.cloud.refresh.extra-refreshable=javax.sql.DataSource or, more appropriately, strongly type your DataSource bean
@Primary
@Bean(name = "dbDataSource")
@ConfigurationProperties(prefix = "datasource.db")
public HikariDataSource dbDataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
意思是说，解决该问题有两种方式：
1.添加配置：spring.cloud.refresh.extra-refreshable=javax.sql.DataSource
2.配置数据源时，指定最终的类型，而不是接口类型。如下：
把
@Bean(name = "masterDataSource")
@Qualifier("masterDataSource")
@ConfigurationProperties(prefix="spring.myself-db.datasource.hikari.master")
public DataSource masterDataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
改成：
@Bean(name = "masterDataSource")
@Qualifier("masterDataSource")
@ConfigurationProperties(prefix="spring.myself-db.datasource.hikari.master")
public DataSource masterDataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
每个地方都改成明确的类型。
如果采用第一种方式，会出现另外一个问题，在后面代码中DynamicDataSource转型为DataSource将会报错。纳闷，狗日的……
因此，只能采用方式二了。把数据源配置改如下：
package com.xrlj.framework.spring.config.ds.myself;
import com.xrlj.framework.dao.ds.DynamicDataSource;
import com.zaxxer.hikari.HikariDataSource;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.*;
/**
* 按规则定死的数据源。一主双从。适用所有服务。
*/
@Configuration
public class DataSourceConfig {
@Bean(name = "masterDataSource")
@Qualifier("masterDataSource")
@ConfigurationProperties(prefix="spring.myself-db.datasource.hikari.master")
public HikariDataSource masterDataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
@Bean(name = "slave1DataSource")
@Qualifier("slave1DataSource")
@ConfigurationProperties(prefix="spring.myself-db.datasource.hikari.slave1")
public HikariDataSource slave1DataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
@Bean(name = "slave2DataSource")
@Qualifier("slave2DataSource")
@ConfigurationProperties(prefix="spring.myself-db.datasource.hikari.slave2")
public HikariDataSource slave2DataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}
/**
* 动态数据源: 通过AOP在不同数据源之间动态切换
*
* @return
*/
@Primary
@Bean(name = "dynamicDataSource")
@Qualifier("dynamicDataSource")
@Scope("singleton")
@DependsOn({"masterDataSource","slave1DataSource","slave2DataSource"}) //要加入这个注解，在数据源初始化之后，再初始化本bean，否则会出现循环依赖注入无法启动。
public DynamicDataSource dynamicDataSource(@Qualifier("masterDataSource") HikariDataSource masterDataSource,
@Qualifier("slave1DataSource") HikariDataSource slave1DataSource,@Qualifier("slave2DataSource") HikariDataSource slave2DataSource) {
DynamicDataSource dynamicDataSource = new DynamicDataSource();
return dynamicDataSource.setMultipleDataSource(masterDataSource,slave1DataSource,slave2DataSource);
}
}
再重新启动各服务，测试：
改动foo的值，刷新页面（post）： localhost:9010/actuator/refresh：
再请求/hi:
我们看到，foo的值已经在线刷新。无需重启服务。
如果是多个实例，只要任何一个实例执行了刷新请求，所有实例都会同步刷新的。
统一在config-server端刷新配置
上面我们的测试，都是对每个业务服务进行配置刷新的。如果业务服务很多的话，就做不到统一刷新了，所以我们这里介绍在配置中心端刷新配置。
流程是，请求config-server的刷新请求，它会向mq发送配置刷新通知，然后，所有参与订阅的服务的配置都会收到刷新的通知时间，然后自动刷新。当然，也可以指定只刷新某个服务的。
更改foo的值，发起刷新请求，注意，请求的是config-server的地址：
http://localhost:3331/actuator/bus-refresh
注意请求地址，是bus-refresh，而不是refresh。否则不成功。
这里要注意下，请求里面要添加认证信息。因为config-server里面引入了spring-security模块，而且要添加安全配置WebSecurityConfiguration,否则会出现请求需要验证或者请求拒绝导致不成功。
看请求结果图，请求返回状态为204 No Content,显示请求成功，但是没有返回内容。不知道为啥……
再次请求业务服务的/hi,可以看到，配置已经在线刷新。成功了！
利用github的Webhooks功能自动刷新
达到的目的是，改动配置后，提交到git仓库，然后触发事件发起请求config-server的刷新请求。达到自动目的。
webhooks的使用，这里不做介绍。
略……