什么是Bus
0.解释
https://spring.io/projects/spring-cloud-bus
springcloudbus使用轻量级消息代理将分布式系统的节点连接起来。然后，可以使用它来广播状态更改（例如配置更改）或其他管理指令。AMQP和Kafka broker实现包含在项目中。或者，在类路径上找到的任何springcloudstream绑定器都可以作为传输使用。
通俗定义: bus称之为springcloud中消息总线,主要用来在微服务系统中实现远端配置更新时通过广播形式通知所有客户端刷新配置信息,避免手动重启服务的工作
实现配置刷新原理
搭建RabbitMQ服务
官方安装包下载:https://www.rabbitmq.com/install-rpm.html#downloads
[注意:][这里安装包只能用于centos7.x系统]
1.将rabbitmq安装包上传到linux系统中
erlang-22.0.7-1.el7.x86_64.rpm rabbitmq-server-3.7.18-1.el7.noarch.rpm2.安装Erlang依赖包
rpm -ivh erlang-22.0.7-1.el7.x86_64.rpm3.安装RabbitMQ安装包(需要联网)
yum install -y rabbitmq-server-3.7.18-1.el7.noarch.rpm 注意:默认安装完成后配置文件模板在:/usr/share/doc/rabbitmq-server-3.7.18/rabbitmq.config.example目录中,需要将配置文件复制到/etc/rabbitmq/目录中,并修改名称为rabbitmq.config4.复制配置文件
cp /usr/share/doc/rabbitmq-server-3.7.18/rabbitmq.config.example /etc/rabbitmq/rabbitmq.config5.查看配置文件位置
ls /etc/rabbitmq/rabbitmq.config6.修改配置文件(参见下图:)
vim /etc/rabbitmq/rabbitmq.config
将上图中配置文件中红色部分去掉%%,以及最后的,逗号 修改为下图:
rabbitmq-plugins enable rabbitmq_management 出现如下说明: Enabling plugins on node rabbit@localhost: rabbitmq_management The following plugins have been configured: rabbitmq_management rabbitmq_management_agent rabbitmq_web_dispatch Applying plugin configuration to rabbit@localhost... The following plugins have been enabled: rabbitmq_management rabbitmq_management_agent rabbitmq_web_dispatch set 3 plugins. Offline change; changes will take effect at broker restart.8.启动RabbitMQ的服务
systemctl start rabbitmq-server systemctl restart rabbitmq-server systemctl stop rabbitmq-server9.查看服务状态(见下图:)
systemctl status rabbitmq-server
● rabbitmq-server.service - RabbitMQ broker
Loaded: loaded (/usr/lib/systemd/system/rabbitmq-server.service; disabled; vendor preset: disabled)
Active: active (running) since 三 2019-09-25 22:26:35 CST; 7s ago
Main PID: 2904 (beam.smp)
Status: “Initialized”
CGroup: /system.slice/rabbitmq-server.service
├─2904 /usr/lib64/erlang/erts-10.4.4/bin/beam.smp -W w -A 64 -MBas ageffcbf -MHas ageffcbf -
MBlmbcs…
├─3220 erl_child_setup 32768
├─3243 inet_gethost 4
└─3244 inet_gethost 4
…
systemctl disable firewalld Removed symlink /etc/systemd/system/multi-user.target.wants/firewalld.service. Removed symlink /etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service. systemctl stop firewalld11.访问web管理界面
http://10.15.0.8:15672/12.登录管理界面
username: guest password: guest 13.MQ服务搭建成功
实现自动配置刷新
1.在所有项目中引入bus依赖2.配置统一配置中心连接到mqorg.springframework.cloud >spring-cloud-starter-bus-amqp
spring.rabbitmq.host=localhost #连接主机 spring.rabbitmq.port=5672 #连接mq端口 spring.rabbitmq.username=user #连接mq用户名 spring.rabbitmq.password=password #连接mq密码3.远端配置中加入连接mq配置 4.启动统一配置中心服务
正常启动
5.启动客户端服务
加入bus组件之后客户端启动报错原因springcloud中默认链接不到远程服务器不会报错,但是在使用bus消息总线时必须开启连接远程服务失败报错
spring.cloud.config.fail-fast=true6.修改远程配置后在配置中心服务通过执行post接口刷新配置
curl -X POST http://localhost:7878/actuator/bus-refresh
7.通过上述配置就实现了配置统一刷新
指定服务刷新配置
1.说明默认情况下使用curl -X POST http://localhost:7878/actuator/bus-refresh这种方式刷新配置是全部广播形式,也就是所有的微服务都能接收到刷新配置通知,但有时我们修改的仅仅是某个服务的配置,这个时候对于其他服务的通知是多余的,因此就需要指定服务进行通知 2.指定服务刷新配置实现
指定端口刷新某个具体服务: curl -X POST http://localhost:7878/actuator/bus-refresh/configclient:9090
指定服务id刷新服务集群节点: curl -X POST http://localhost:7878/actuator/bus-refresh/configclient
[注意:][configclient代表刷新服务的唯一标识]
集成webhook实现自动刷新
1.配置webhooks添加webhooks
在webhooks中添加刷新配置接口
内网穿透可以使用natapp进行穿透，本地一个穿透免费穿透，https://natapp.cn/ 步骤非常简单。然后将穿透的地址放入到所需地址栏即可。
在配置中心服务端加入过滤器进行解决(springcloud中一个坑)
@Component
public class UrlFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
HttpServletRequest httpServletRequest = (HttpServletRequest)request;
HttpServletResponse httpServletResponse = (HttpServletResponse)response;
String url = new String(httpServletRequest.getRequestURI());
//只过滤/actuator/bus-refresh请求
if (!url.endsWith("/bus-refresh")) {
chain.doFilter(request, response);
return;
}
//获取原始的body
String body = readAsChars(httpServletRequest);
System.out.println("original body: "+ body);
//使用HttpServletRequest包装原始请求达到修改post请求中body内容的目的
CustometRequestWrapper requestWrapper = new CustometRequestWrapper(httpServletRequest);
chain.doFilter(requestWrapper, response);
}
@Override
public void destroy() {
}
private class CustometRequestWrapper extends HttpServletRequestWrapper {
public CustometRequestWrapper(HttpServletRequest request) {
super(request);
}
@Override
public ServletInputStream getInputStream() throws IOException {
byte[] bytes = new byte[0];
ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(bytes);
return new ServletInputStream() {
@Override
public boolean isFinished() {
return byteArrayInputStream.read() == -1 ? true:false;
}
@Override
public boolean isReady() {
return false;
}
@Override
public void setReadListener(ReadListener readListener) {
}
@Override
public int read() throws IOException {
return byteArrayInputStream.read();
}
};
}
}
public static String readAsChars(HttpServletRequest request)
{
BufferedReader br = null;
StringBuilder sb = new StringBuilder("");
try
{
br = request.getReader();
String str;
while ((str = br.readLine()) != null)
{
sb.append(str);
}
br.close();
}
catch (IOException e)
{
e.printStackTrace();
}
finally
{
if (null != br)
{
try
{
br.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
return sb.toString();
}
}
