1. 安装sentinel , https://github.com/alibaba/Sentinel/tree/release-1.8
   下载最新的sentinel（1.8）源码到本地
2. 注释掉pom.xml中的 sentinel-datasource-nacos
   中的test
3. 修改resources/app/scripts/directives/sidebar/sidebar.html,
   将flowV1改成flow,这样设置规则的时候默认走v2,如下，稍后访问sentinel的时候清理下浏览器缓存。

          <li ui-sref-active="active" ng-if="!entry.isGateway">
            <a ui-sref="dashboard.flow({app: entry.app})">
              <i class="glyphicon glyphicon-filter"></i>&nbsp;&nbsp;流控规则</a>
          </li>

4. 在com.alibaba.csp.sentinel.dashboard.rule下创建nacos文件夹创建如下代码，后面5、6、7、8步都在该nacos文件夹下创建：

//加载外部化配置
@ConfigurationProperties(prefix="sentinel.nacos",ignoreUnknownFields = true)
public class NacosPropertiesConfiguration {

    private String serverAddr;
    private String dataId;
    private String groupId = "DEFAULT_GROUP";
    private String namespace;

    public String getServerAddr() {
        return serverAddr;
    }

    public void setServerAddr(String serverAddr) {
        this.serverAddr = serverAddr;
    }

    public String getDataId() {
        return dataId;
    }

    public void setDataId(String dataId) {
        this.dataId = dataId;
    }

    public String getGroupId() {
        return groupId;
    }

    public void setGroupId(String groupId) {
        this.groupId = groupId;
    }

    public String getNamespace() {
        return namespace;
    }

    public void setNamespace(String namespace) {
        this.namespace = namespace;
    }
}

5. 创建配置类 NacosConfiguration

@EnableConfigurationProperties(NacosPropertiesConfiguration.class)
@Configuration
public class NacosConfiguration {

    @Bean
    public Converter<List<FlowRuleEntity>,String> flowRuleEntityEncoder(){
        return JSON::toJSONString;
    }

    @Bean
    public Converter<String,List<FlowRuleEntity>> flowRuleEntityDecoder(){
        return s -> JSON.parseArray(s, FlowRuleEntity.class);
    }

    @Bean
    public ConfigService nacosConfigService(NacosPropertiesConfiguration nacosPropertiesConfiguration) throws NacosException {
        Properties properties = new Properties();
        properties.put(PropertyKeyConst.SERVER_ADDR, nacosPropertiesConfiguration.getServerAddr());
        properties.put(PropertyKeyConst.NAMESPACE, nacosPropertiesConfiguration.getNamespace());
        return ConfigFactory.createConfigService(properties);
    }
}

6. 创建一个常量类 NacosConstants

public class NacosConstants {
    public static final String DATA_ID_POSTFIX = "-sentinel-flow";
    public static final String GROUP_ID = "DEFAULT_GROUP";
}

7. 实现动态从nacos配置中心获取流控规则

@Service
public class FlowRuleNacosProvider implements DynamicRuleProvider<List<FlowRuleEntity>> {
    private static Logger logger = LoggerFactory.getLogger(FlowRuleNacosProvider.class);

    @Autowired
    private NacosPropertiesConfiguration nacosConfigProperties;

    @Autowired
    private ConfigService configService;

    @Autowired
    private Converter<String, List<FlowRuleEntity>> converter;

    @Override
    public List<FlowRuleEntity> getRules(String appName) throws Exception {
        String dataID=new StringBuilder(appName).append(NacosConstants.DATA_ID_POSTFIX).toString();
        String rules = configService.getConfig(dataID, nacosConfigProperties.getGroupId(), 3000);
        logger.info("pull FlowRule from Nacos Config:{}",rules);
        if (StringUtil.isEmpty(rules)) {
            return new ArrayList<>();
        }
        return converter.convert(rules);
    }
}

8. 创建一个流控规则发布类

@Service
public class FlowRuleNacosPublisher implements DynamicRulePublisher<List<FlowRuleEntity>> {

    @Autowired
    private NacosPropertiesConfiguration nacosPropertiesConfiguration;

    @Autowired
    private ConfigService configService;
    @Autowired
    private Converter<List<FlowRuleEntity>, String> converter;

    @Override
    public void publish(String appName, List<FlowRuleEntity> rules) throws Exception {
        AssertUtil.notEmpty(appName, "appName cannot be empty");
        if (rules == null) {
            return;
        }
        String dataID=new StringBuilder(appName).append(NacosConstants.DATA_ID_POSTFIX).toString();
        configService.publishConfig(dataID, nacosPropertiesConfiguration.getGroupId(), converter.convert(rules));
    }
}

9. 修改FlowControllerV2类，将7、8步中的类配置进来

@RestController
@RequestMapping(value = "/v2/flow")
public class FlowControllerV2 {

    private final Logger logger = LoggerFactory.getLogger(FlowControllerV2.class);

    @Autowired
    private InMemoryRuleRepositoryAdapter<FlowRuleEntity> repository;

    @Autowired
    @Qualifier("flowRuleNacosProvider")
    private DynamicRuleProvider<List<FlowRuleEntity>> ruleProvider;
    @Autowired
    @Qualifier("flowRuleNacosPublisher")
    private DynamicRulePublisher<List<FlowRuleEntity>> rulePublisher;

10. 在application.properties文件中添加Nacos的服务端配置信息

sentinel.nacos.serverAddr=IP:8848
# namespace不配置默认走public命名空间
sentinel.nacos.namespace=fb4f87e6-806d-4a03-85f8-5d55f143f042
sentinel.nacos.groupId=DEFAULT_GROUP