SpringCloud - Spring Cloud Alibaba 之 Gateway 集成Sentinel；SPI机制（十一）

迈不过友情╰ 2023-09-28 16:37 9阅读 0赞

#### 阅读本文前可先参考 ####

[SpringCloud - Spring Cloud 之 Gateway网关（十三）\_MinggeQingchun的博客-CSDN博客\_spring.cloud.gateway.routes\[0\]][SpringCloud - Spring Cloud _ Gateway_MinggeQingchun_-CSDN_spring.cloud.gateway.routes_0]

[SpringCloud - Spring Cloud Alibaba 之 Sentinel 规则持久化（十）\_MinggeQingchun的博客-CSDN博客][SpringCloud - Spring Cloud Alibaba _ Sentinel _MinggeQingchun_-CSDN]

## 一、Gateway 集成Sentinel ##

Gateway网关集成Sentinel是为了流控、熔断、降级

1、添加 sentinel-spring-cloud-gateway-adapter 依赖

<dependency>
 <groupId>com.alibaba.csp</groupId>
 <artifactId>sentinel-spring-cloud-gateway-adapter</artifactId>
 <version>1.8.0</version>
 </dependency>

2、添加sentinel控制台配置

#sentinel dashboard管理后台
    spring：
      cloud：
        sentinel:
          eager: true
          transport:
            dashboard: 192.168.172.128:8080

3、在配置类spring容器中配置一个Sentinel的全局过滤器

@Configuration
    public class GatewayConfiguration {
    
        //省略号代表其它配置
        ......
    
        @Bean
        @Order(-1)
        public GlobalFilter sentinelGatewayFilter() {
            return new SentinelGatewayFilter();
        }
    
        ......
    }

4、启动测试

（1）启动Nacos（如果使用MySQL数据持久化，则要先启动mysql服务）

cd /opt/software/nacos/bin/
    
    sh startup.sh -m standalone

启动MySQL服务（如果docker启动，先启动docker并挂载mysql，防止数据丢失）

http://192.168.133.129:8848/nacos

（2）启动Sentinel DashBoard控制台

cd /opt/software/sentinel-dashboard-1.8.4/
    
    java -jar sentinel-dashboard-1.8.4.jar

http://192.168.133.129:8080/

（3）分别启动服务提供者、服务消费者

（4）启动Spring Cloud Gateway

（5）浏览器输入访问

http://localhost:8081/test

## 二、Spring Cloud Gateway集成Sentinel规则持久化 ##

#### 一、使用SPI配置 ####

1、在application.properties中配置依赖

<dependency>
 <groupId>com.alibaba.csp</groupId>
 <artifactId>sentinel-datasource-extension</artifactId>
 </dependency>

由于之前添加过了 **spring-cloud-starter-alibaba-sentinel** 依赖，包含了 **sentinel-datasource** 依赖，此处可以不加

![88a7af64281644a9a6306b4e99d51647.png][]

2、自定义 FileDataSourceInit 类 实现 InitFunc（配置文件暂时不动）

import com.alibaba.csp.sentinel.command.handler.ModifyParamFlowRulesCommandHandler;
 import com.alibaba.csp.sentinel.datasource.*;
 import com.alibaba.csp.sentinel.init.InitFunc;
 import com.alibaba.csp.sentinel.slots.block.authority.AuthorityRule;
 import com.alibaba.csp.sentinel.slots.block.authority.AuthorityRuleManager;
 import com.alibaba.csp.sentinel.slots.block.degrade.DegradeRule;
 import com.alibaba.csp.sentinel.slots.block.degrade.DegradeRuleManager;
 import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
 import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
 import com.alibaba.csp.sentinel.slots.block.flow.param.ParamFlowRule;
 import com.alibaba.csp.sentinel.slots.block.flow.param.ParamFlowRuleManager;
 import com.alibaba.csp.sentinel.slots.system.SystemRule;
 import com.alibaba.csp.sentinel.slots.system.SystemRuleManager;
 import com.alibaba.csp.sentinel.transport.util.WritableDataSourceRegistry;
 import com.alibaba.fastjson.JSON;
 import com.alibaba.fastjson.TypeReference;
 
 import java.io.File;
 import java.io.IOException;
 import java.util.List;
 
 /**
 * 规则持久化
 */
 public class FileDataSourceInit implements InitFunc {
 
 @Override
 public void init() throws Exception {
 //可以根据需要指定规则文件的位置
 //"user.home" 即C盘 C:\Users\用户名 下
 String ruleDir = System.getProperty("user.home") + "/sentinel/rules";
 
 String flowRulePath = ruleDir + "/flow-rule.json";
 String degradeRulePath = ruleDir + "/degrade-rule.json";
 String paramFlowRulePath = ruleDir + "/param-flow-rule.json";
 String systemRulePath = ruleDir + "/system-rule.json";
 String authorityRulePath = ruleDir + "/authority-rule.json";
 
 this.mkdirIfNotExits(ruleDir);
 
 this.createFileIfNotExits(flowRulePath);
 this.createFileIfNotExits(degradeRulePath);
 this.createFileIfNotExits(paramFlowRulePath);
 this.createFileIfNotExits(systemRulePath);
 this.createFileIfNotExits(authorityRulePath);
 
 
 //以下代码从官网拷贝过来
 // 流控规则：可读数据源
 ReadableDataSource<String, List<FlowRule>> flowRuleRDS = new FileRefreshableDataSource<>(
 flowRulePath,
 flowRuleListParser
 );
 // 将可读数据源注册至FlowRuleManager
 // 这样当规则文件发生变化时，就会更新规则到内存
 FlowRuleManager.register2Property(flowRuleRDS.getProperty());
 // 流控规则：可写数据源
 WritableDataSource<List<FlowRule>> flowRuleWDS = new FileWritableDataSource<>(
 flowRulePath,
 this::encodeJson
 );
 // 将可写数据源注册至transport模块的WritableDataSourceRegistry中
 // 这样收到控制台推送的规则时，Sentinel会先更新到内存，然后将规则写入到文件中
 WritableDataSourceRegistry.registerFlowDataSource(flowRuleWDS);
 
 
 // 降级规则：可读数据源
 ReadableDataSource<String, List<DegradeRule>> degradeRuleRDS = new FileRefreshableDataSource<>(
 degradeRulePath,
 degradeRuleListParser
 );
 DegradeRuleManager.register2Property(degradeRuleRDS.getProperty());
 // 降级规则：可写数据源
 WritableDataSource<List<DegradeRule>> degradeRuleWDS = new FileWritableDataSource<>(
 degradeRulePath,
 this::encodeJson
 );
 WritableDataSourceRegistry.registerDegradeDataSource(degradeRuleWDS);
 
 
 // 热点参数规则：可读数据源
 ReadableDataSource<String, List<ParamFlowRule>> paramFlowRuleRDS = new FileRefreshableDataSource<>(
 paramFlowRulePath,
 paramFlowRuleListParser
 );
 ParamFlowRuleManager.register2Property(paramFlowRuleRDS.getProperty());
 // 热点参数规则：可写数据源
 WritableDataSource<List<ParamFlowRule>> paramFlowRuleWDS = new FileWritableDataSource<>(
 paramFlowRulePath,
 this::encodeJson
 );
 ModifyParamFlowRulesCommandHandler.setWritableDataSource(paramFlowRuleWDS);
 
 
 // 系统规则：可读数据源
 ReadableDataSource<String, List<SystemRule>> systemRuleRDS = new FileRefreshableDataSource<>(
 systemRulePath,
 systemRuleListParser
 );
 SystemRuleManager.register2Property(systemRuleRDS.getProperty());
 // 系统规则：可写数据源
 WritableDataSource<List<SystemRule>> systemRuleWDS = new FileWritableDataSource<>(
 systemRulePath,
 this::encodeJson
 );
 WritableDataSourceRegistry.registerSystemDataSource(systemRuleWDS);
 
 
 // 授权规则：可读数据源
 ReadableDataSource<String, List<AuthorityRule>> authorityRuleRDS = new FileRefreshableDataSource<>(
 authorityRulePath,
 authorityRuleListParser
 );
 AuthorityRuleManager.register2Property(authorityRuleRDS.getProperty());
 // 授权规则：可写数据源
 WritableDataSource<List<AuthorityRule>> authorityRuleWDS = new FileWritableDataSource<>(
 authorityRulePath,
 this::encodeJson
 );
 WritableDataSourceRegistry.registerAuthorityDataSource(authorityRuleWDS);
 }
 
 
 private Converter<String, List<FlowRule>> flowRuleListParser = source -> JSON.parseObject(
 source,
 new TypeReference<List<FlowRule>>() {
 }
 );
 
 private Converter<String, List<DegradeRule>> degradeRuleListParser = source -> JSON.parseObject(
 source,
 new TypeReference<List<DegradeRule>>() {
 }
 );
 
 private Converter<String, List<SystemRule>> systemRuleListParser = source -> JSON.parseObject(
 source,
 new TypeReference<List<SystemRule>>() {
 }
 );
 
 private Converter<String, List<AuthorityRule>> authorityRuleListParser = source -> JSON.parseObject(
 source,
 new TypeReference<List<AuthorityRule>>() {
 }
 );
 
 private Converter<String, List<ParamFlowRule>> paramFlowRuleListParser = source -> JSON.parseObject(
 source,
 new TypeReference<List<ParamFlowRule>>() {
 }
 );
 
 private void mkdirIfNotExits(String filePath) throws IOException {
 File file = new File(filePath);
 if (!file.exists()) {
 file.mkdirs();
 }
 }
 
 private void createFileIfNotExits(String filePath) throws IOException {
 File file = new File(filePath);
 if (!file.exists()) {
 file.createNewFile();
 }
 }
 
 private <T> String encodeJson(T t) {
 return JSON.toJSONString(t);
 }
 }

3、配置SPI（Service Provider Interface，JDK内置的一种服务提供发现机制，可以用来启用框架扩展和替换组件）

Java SPI是一种以接口为基础，使用配置文件来加载（或称之为服务发现）的动态加载机制，主要使用JDK中ServiceLoader来实现

（1）在classPath下 resources 创建路径META-INF/services/目录下 创建一个 文件 com.alibaba.csp.sentinel.init.InitFunc（以接口的全路径做为名称，不要带文件格式后缀）

（2）将自定义的类 包路径名拷贝至此（实现类的全路径）

![b34f3e5207fd4112b0c19635be020539.png][] ![cc3af5cc0f2046089e22589bad6f6c4d.png][]

![1ba12ab55ef04032ba5bf3c24314f80e.png][]

4、启动消费者服务，此时去 Sentinel DashBoard中创建一条流控规则

![b2342bf39f6843bf8c3b4229c5ca0369.png][]根据自定义类 FileDataSourceInit 中 存放sentinel 规则的文件夹，

即 C:\\Users\\用户名\\sentinel\\rules 可找到相应Sentinel 规则持久化的JSON文件

//可以根据需要指定规则文件的位置
            //"user.home" 即C盘 C:\Users\用户名 下
            String ruleDir = System.getProperty("user.home") + "/sentinel/rules";

![89028ad64e054060ac9a81a3d9e0a19d.png][]

#### 二、使用Nacos配置 ####

1、添加sentinel-datasource-nacos依赖；

<dependency>
 <groupId>com.alibaba.csp</groupId>
 <artifactId>sentinel-datasource-nacos</artifactId>
 </dependency>

2、application.properties配置持久化数据源

#配置sentinel规则持久化到nacos
    datasource:
      ncs1:
        nacos:
          server-addr: 192.168.133.128:80
          data-id: ${spring.application.name}.json
          group-id: DEFAULT_GROUP
          rule-type: flow
          data-type: json
    
    degrade:
       nacos:
         server-addr: 192.168.133.128:80
         data-id: ${spring.application.name}-degrade.json
         group-id: DEFAULT_GROUP
         rule-type: degrade
         data-type: json

3、在nacos配置中心配置流控规则

[
      {
        "resource": "abc",
        "controlBehavior": 0,
        "count": 1.0,
        "grade": 1,
        "limitApp": "default",
        "strategy": 0
      }
    ]

## 三、Sprng Cloud Gateway跨域CORS ##

可参考 [https://blog.csdn.net/MinggeQingchun/article/details/125538531][https_blog.csdn.net_MinggeQingchun_article_details_125538531]

传统的Ajax请求只能获取在同一个域名下的资源，但是HTML5规范中打破了这种限制，允许Ajax发起跨域的请求（需要设置一下）

其实浏览器本身是可以发起跨域请求的，比如你可以链接一个另一个域名下的图片或者js，比如<img src=http://www.baidu.com/image/logo.png>，但是javascript脚本是不能获取这些另一个域名下的资源内容的

**CORS**是一个W3C标准，全称是”**跨域资源共享**”（**Cross-origin resource sharing**），允许浏览器向跨源服务器，发出XMLHttpRequest请求，从而克服了AJAX只能同源使用的限制

这种CORS使用了一个额外的HTTP响应头来赋予当前user-agent（浏览器）获得跨域资源的权限，这里的跨域也就是Cross-Origin的概念，这里的权限就是访问另一个域名下的资源权限

CORS是现在HTML5标准中的一部分，在大部分现代浏览器中都有所支持，可能在某些老版本的浏览器不支持CORS，如果要兼容一些老的浏览器版本，则需要采用JSONP进行跨域请求

###  ###

### 同源与非同源（跨域和不跨域） ###

如果 **访问****协议、端口（**如果指定了端口**）、host** 都相同，则称之为**同源****（不跨域）**，否则为**非同源（跨域）**

如源链接： http://shop.company.com/good/page.html

<table style="margin-left:-5.1pt;"> 
 <tbody> 
 <tr> 
 <td style="background-color:#fafafa;"> URL </td> 
 <td style="background-color:#fafafa;"> 是否同源 </td> 
 <td style="background-color:#fafafa;"> 原因 </td> 
 </tr> 
 <tr> 
 <td style="background-color:#ffffff;"> <a href="http://store.company.com/dir2/other.html" title="http://shop.company.com/good2/other.html" rel="nofollow">http://shop.company.com/good2/other.html</a> </td> 
 <td style="background-color:#ffffff;"> 是 </td> 
 <td style="background-color:#ffffff;"> </td> 
 </tr> 
 <tr> 
 <td style="background-color:#ffffff;"> <a href="http://store.company.com/dir/inner/another.html" title="http://shop.company.com/good/inner/another.html" rel="nofollow">http://shop.company.com/good/inner/another.html</a> </td> 
 <td style="background-color:#ffffff;"> 是 </td> 
 <td style="background-color:#ffffff;"> </td> 
 </tr> 
 <tr> 
 <td style="background-color:#ffffff;"> <a href="https://store.company.com/secure.html" title="https://shop.company.com/good.html" rel="nofollow">https://shop.company.com/good.html</a> </td> 
 <td style="background-color:#ffffff;"> 否 </td> 
 <td style="background-color:#ffffff;"> 协议不同 </td> 
 </tr> 
 <tr> 
 <td style="background-color:#ffffff;"> <a href="http://store.company.com:81/dir/etc.html" title="http://shop.company.com:81/good/etc.html" rel="nofollow">http://shop.company.com:81/good/etc.html</a> </td> 
 <td style="background-color:#ffffff;"> 否 </td> 
 <td style="background-color:#ffffff;"> 端口不同 </td> 
 </tr> 
 <tr> 
 <td style="background-color:#ffffff;"> <a href="http://news.company.com/dir/other.html" title="http://news.company.com/good/other.html" rel="nofollow">http://news.company.com/good/other.html</a> </td> 
 <td style="background-color:#ffffff;"> 否 </td> 
 <td style="background-color:#ffffff;"> host不同 </td> 
 </tr> 
 </tbody> 
</table>

解决跨域：

/**
     * 配置网关跨域cors请求支持
     */
    @Configuration
    public class CorsConfig {
    
        @Bean
        public CorsWebFilter corsFilter() {
            CorsConfiguration config = new CorsConfiguration();
            config.addAllowedMethod("*"); //是什么请求方法，比如 GET POST PUT DELATE .....
            config.addAllowedOrigin("*"); //来自哪个域名的请求，*号表示所有
            config.addAllowedHeader("*"); //是什么请求头
    
            UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource(new PathPatternParser());
            source.registerCorsConfiguration("/**", config);
    
            return new CorsWebFilter(source);
        }
    }

[SpringCloud - Spring Cloud _ Gateway_MinggeQingchun_-CSDN_spring.cloud.gateway.routes_0]: https://blog.csdn.net/MinggeQingchun/article/details/125334406
[SpringCloud - Spring Cloud Alibaba _ Sentinel _MinggeQingchun_-CSDN]: https://blog.csdn.net/MinggeQingchun/article/details/125759870
[88a7af64281644a9a6306b4e99d51647.png]: https://img-blog.csdnimg.cn/88a7af64281644a9a6306b4e99d51647.png
[b34f3e5207fd4112b0c19635be020539.png]: https://img-blog.csdnimg.cn/b34f3e5207fd4112b0c19635be020539.png
[cc3af5cc0f2046089e22589bad6f6c4d.png]: https://img-blog.csdnimg.cn/cc3af5cc0f2046089e22589bad6f6c4d.png
[1ba12ab55ef04032ba5bf3c24314f80e.png]: https://img-blog.csdnimg.cn/1ba12ab55ef04032ba5bf3c24314f80e.png
[b2342bf39f6843bf8c3b4229c5ca0369.png]: https://img-blog.csdnimg.cn/b2342bf39f6843bf8c3b4229c5ca0369.png
[89028ad64e054060ac9a81a3d9e0a19d.png]: https://img-blog.csdnimg.cn/89028ad64e054060ac9a81a3d9e0a19d.png
[https_blog.csdn.net_MinggeQingchun_article_details_125538531]: https://blog.csdn.net/MinggeQingchun/article/details/125538531