Sentinel rules persist to Nacos

​​​​​​ As mentioned above Sentinel If the rules of need persistence , You need to use push or pull mode

• Pull mode ： The client takes the initiative to poll a rule management center regularly for pull rules , The center of the rule can be RDBMS、 file , Even VCS etc. . The way to do this is simple , The disadvantage is that you can't get changes in time ;
• Push mode ： The rule center pushes , The client listens for changes all the time by registering a listener , For example, use  Nacos、Zookeeper Wait for the configuration center . This way has better real-time and consistency guarantee .

In this paper Nacos That is, push pattern persistence rules , This way of interaction is cut off Sentinel Client and Sentinel Dashboard The connection of . Its interaction mode is like this ： When Sentinel Dashboard After rule change , It will be pushed to Nacos, Again Nacos Push to client , As shown in the figure below ：

This method needs to be modified in two places ：

1、 modify Sentinel Dashboard Source code （ Actually Dashboard It's connected to nacos, We just need to replace the default implementation ）

2、Sentinel Client access Nacos

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modify Sentinel Dashboard Source code

1、 download Sentinel Dashboard project

https://github.com/alibaba/Sentinel/tree/master/sentinel-dashboard

Download too slow, click here

2、 take test The contents are about Nacos copy to com.alibaba.csp.sentinel.dashboard.rule

among FlowRuleNacosProvider From Nacos Middle pull rule ,FlowRuleNacosPublisher Will send to Nacos Push rules , This is a Dashboard The implementation provided for us

3、 Then replace FlowControllerV2 Class DynamicRuleProvider by Nacos The implementation of the

 4、 Then the front-end page should also be changed to call v2 The interface of , Call by default /v1/flow

• sidebar.html（resources/app/scripts/directives/sidebar） page Control rule routing from  dashboard.flowV1  Change to  dashboard.flow
  
• app.js(resources/dist/js/app.js) take app/scripts/controllers/flow_v1.js
Replace with app/scripts/controllers/flow_v2.js
  

 Sentinel Dashboard Modified to complete ！！

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Sentinel Client access Nacos 

1、 Installing the Nacos

2、Sentinel in the light of Nacos The results showed that there was no significant difference between the two groups , The bottom layer can adopt Nacos As a rule configuration data source . Just add the following dependencies when using ：

        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-datasource-nacos</artifactId>
            <version>1.8.0</version>
        </dependency>

Complete dependence ：

    <!--  rely on web -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- sentinel springboot-starter -->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
            <version>2021.1</version>
        </dependency>
        <!-- sentinel  Core dependence -->
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-core</artifactId>
            <version>1.8.0</version>
        </dependency>
        <!--sentinel Persistence  -->
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-datasource-nacos</artifactId>
            <version>1.8.0</version>
        </dependency>

 Yml To configure

server:
  port: 8081
spring:
  application:
    name: sentinel
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
    sentinel:
      transport:
        dashboard: 127.0.0.1:8080 # Appoint sentinel dashboard web  Address 
      datasource:
        ds1:   # Name customization , only 
          nacos:
            server-addr: 127.0.0.1:8848
            dataId: ${spring.application.name}-flow-rules
            groupId: SENTINEL_GROUP
            data-type: json
            rule-type: flow

among dataId and groupId Want to be with Sentinel Dashboard in FlowRuleNacosPublisher the push The consistency of , The default values are as follows , So we can also set the default value

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Then start one by one Sentinel Dashboard and Sentinel The client can , from Dashboard The rules modified in will be immediately pushed to Nacos, from Nacos Added rules Dashboard Can also sense , And even if the client or Dashboard restart , Data can also be obtained from Nacos Read it out , Persistence is achieved