Sentinel Dashboard 与 Nacos 集成代码模板详解：实现流控规则持久化至 Nacos

Sentinel Nacos 规则持久化代码解析

本文介绍 Sentinel Dashboard 集成 Nacos 作为动态规则配置中心的实现代码。

NacosConfig.java

/* * Copyright 1999-2018 Alibaba Group Holding Ltd. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */packagecom.alibaba.csp.sentinel.dashboard.rule.nacos;importjava.util.List;importcom.alibaba.csp.sentinel.dashboard.datasource.entity.rule.FlowRuleEntity;importcom.alibaba.csp.sentinel.datasource.Converter;importcom.alibaba.fastjson.JSON;importcom.alibaba.nacos.api.config.ConfigFactory;importcom.alibaba.nacos.api.config.ConfigService;importorg.springframework.context.annotation.Bean;importorg.springframework.context.annotation.Configuration;/** * @author Eric Zhao * @since 1.4.0 */@ConfigurationpublicclassNacosConfig{@BeanpublicConverter<List<FlowRuleEntity>,String>flowRuleEntityEncoder(){returnJSON::toJSONString;}@BeanpublicConverter<String,List<FlowRuleEntity>>flowRuleEntityDecoder(){returns->JSON.parseArray(s,FlowRuleEntity.class);}@BeanpublicConfigServicenacosConfigService()throwsException{returnConfigFactory.createConfigService("localhost");}}

NacosConfigUtil.java

/* * Copyright 1999-2018 Alibaba Group Holding Ltd. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */packagecom.alibaba.csp.sentinel.dashboard.rule.nacos;/** * @author Eric Zhao * @since 1.4.0 */publicfinalclassNacosConfigUtil{publicstaticfinalStringGROUP_ID="SENTINEL_GROUP";publicstaticfinalStringFLOW_DATA_ID_POSTFIX="-flow-rules";publicstaticfinalStringPARAM_FLOW_DATA_ID_POSTFIX="-param-rules";publicstaticfinalStringCLUSTER_MAP_DATA_ID_POSTFIX="-cluster-map";/** * cc for `cluster-client` */publicstaticfinalStringCLIENT_CONFIG_DATA_ID_POSTFIX="-cc-config";/** * cs for `cluster-server` */publicstaticfinalStringSERVER_TRANSPORT_CONFIG_DATA_ID_POSTFIX="-cs-transport-config";publicstaticfinalStringSERVER_FLOW_CONFIG_DATA_ID_POSTFIX="-cs-flow-config";publicstaticfinalStringSERVER_NAMESPACE_SET_DATA_ID_POSTFIX="-cs-namespace-set";privateNacosConfigUtil(){}}

FlowRuleNacosPublisher.java

/* * Copyright 1999-2018 Alibaba Group Holding Ltd. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */packagecom.alibaba.csp.sentinel.dashboard.rule.nacos;importjava.util.List;importcom.alibaba.csp.sentinel.dashboard.datasource.entity.rule.FlowRuleEntity;importcom.alibaba.csp.sentinel.dashboard.rule.DynamicRulePublisher;importcom.alibaba.csp.sentinel.datasource.Converter;importcom.alibaba.csp.sentinel.util.AssertUtil;importcom.alibaba.nacos.api.config.ConfigService;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.stereotype.Component;/** * @author Eric Zhao * @since 1.4.0 */@Component("flowRuleNacosPublisher")publicclassFlowRuleNacosPublisherimplementsDynamicRulePublisher<List<FlowRuleEntity>>{@AutowiredprivateConfigServiceconfigService;@AutowiredprivateConverter<List<FlowRuleEntity>,String>converter;@Overridepublicvoidpublish(Stringapp,List<FlowRuleEntity>rules)throwsException{AssertUtil.notEmpty(app,"app name cannot be empty");if(rules==null){return;}configService.publishConfig(app+NacosConfigUtil.FLOW_DATA_ID_POSTFIX,NacosConfigUtil.GROUP_ID,converter.convert(rules));}}

FlowRuleNacosProvider.java

/* * Copyright 1999-2018 Alibaba Group Holding Ltd. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */packagecom.alibaba.csp.sentinel.dashboard.rule.nacos;importjava.util.ArrayList;importjava.util.List;importcom.alibaba.csp.sentinel.dashboard.datasource.entity.rule.FlowRuleEntity;importcom.alibaba.csp.sentinel.dashboard.rule.DynamicRuleProvider;importcom.alibaba.csp.sentinel.datasource.Converter;importcom.alibaba.csp.sentinel.util.StringUtil;importcom.alibaba.nacos.api.config.ConfigService;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.stereotype.Component;/** * @author Eric Zhao * @since 1.4.0 */@Component("flowRuleNacosProvider")publicclassFlowRuleNacosProviderimplementsDynamicRuleProvider<List<FlowRuleEntity>>{@AutowiredprivateConfigServiceconfigService;@AutowiredprivateConverter<String,List<FlowRuleEntity>>converter;@OverridepublicList<FlowRuleEntity>getRules(StringappName)throwsException{Stringrules=configService.getConfig(appName+NacosConfigUtil.FLOW_DATA_ID_POSTFIX,NacosConfigUtil.GROUP_ID,3000);if(StringUtil.isEmpty(rules)){returnnewArrayList<>();}returnconverter.convert(rules);}}

1.NacosConfigUtil.java- 配置常量类

这是一个工具类，定义了 Nacos 中存储 Sentinel 规则的命名规范。

核心常量：

GROUP_ID="SENTINEL_GROUP"// Nacos 配置分组

Data ID 后缀规范：

作用：统一管理 Nacos 配置的命名规则，避免硬编码。

2.NacosConfig.java- Spring 配置类

这是 Spring Boot 配置类，用于创建 Nacos 相关的 Bean。

三个关键 Bean：

①flowRuleEntityEncoder- 规则编码器

returnJSON::toJSONString;

• 将List<FlowRuleEntity>转换为 JSON 字符串
• 用于发布规则到 Nacos 时序列化

②flowRuleEntityDecoder- 规则解码器

returns->JSON.parseArray(s,FlowRuleEntity.class);

• 将 JSON 字符串解析为List<FlowRuleEntity>
• 用于从 Nacos 读取规则时反序列化

③nacosConfigService- Nacos 客户端

ConfigFactory.createConfigService("localhost");

• 创建 Nacos ConfigService 实例
• 注意：这里硬编码了localhost，生产环境需要改为实际的 Nacos 地址

3.FlowRuleNacosPublisher.java- 规则发布器

实现DynamicRulePublisher接口，负责将流控规则推送到 Nacos。

核心方法：

publicvoidpublish(Stringapp,List<FlowRuleEntity>rules)throwsException{AssertUtil.notEmpty(app,"app name cannot be empty");if(rules==null){return;}configService.publishConfig(app+NacosConfigUtil.FLOW_DATA_ID_POSTFIX,// Data ID: myapp-flow-rulesNacosConfigUtil.GROUP_ID,// Group: SENTINEL_GROUPconverter.convert(rules)// 转换为 JSON);}

执行流程：

1. 校验app 名称不为空
2. 构造 Data ID：应用名 +-flow-rules
3. 序列化规则：通过converter将规则列表转为 JSON
4. 发布配置：调用 Nacos API 发布到指定分组

使用场景：

• Dashboard 页面修改流控规则时
• 规则保存到 Nacos 持久化

4.FlowRuleNacosProvider.java- 规则提供器

实现DynamicRuleProvider接口，负责从 Nacos 拉取流控规则。

核心方法：

publicList<FlowRuleEntity>getRules(StringappName)throwsException{Stringrules=configService.getConfig(appName+NacosConfigUtil.FLOW_DATA_ID_POSTFIX,// Data IDNacosConfigUtil.GROUP_ID,// Group3000// 超时 3 秒);if(StringUtil.isEmpty(rules)){returnnewArrayList<>();// 无配置返回空列表}returnconverter.convert(rules);// 反序列化}

执行流程：

1. 从 Nacos 获取配置：根据 Data ID 和 Group 查询
2. 检查空值：如果配置为空，返回空列表
3. 反序列化：将 JSON 字符串解析为规则对象列表

使用场景：

• Dashboard 启动时加载规则
• 页面刷新时重新拉取规则

架构设计亮点

1.解耦设计

Publisher (发布) ←→ Nacos ←→ Provider (拉取)

• 读写分离，职责清晰
• 通过接口定义，易于扩展到其他配置中心（Apollo、Consul 等）

2.转换器模式

Converter<List<FlowRuleEntity>,String>// 编码Converter<String,List<FlowRuleEntity>>// 解码

• 统一序列化/反序列化逻辑
• 可替换 JSON 实现（如换成 Jackson）

3.配置规范化

• 通过NacosConfigUtil统一命名规则
• 避免不同模块使用不同的 Data ID 规范

实际应用示例

在 Nacos 中的配置结构：

Data ID: myapp-flow-rules Group: SENTINEL_GROUP Content: [ { "resource": "/api/test", "limitApp": "default", "grade": 1, "count": 10, "strategy": 0, "controlBehavior": 0 } ]

Dashboard 使用流程：

1. 用户在 Dashboard 修改规则
2. 调用FlowRuleNacosPublisher.publish()推送到 Nacos
3. Nacos 通知客户端应用（通过监听器）
4. 客户端应用更新本地规则缓存
5. Dashboard 通过FlowRuleNacosProvider.getRules()刷新显示

注意事项

⚠️ 需要修改的地方：

1. Nacos 地址硬编码

// 生产环境需要改为：ConfigFactory.createConfigService("nacos-server:8848");

2. 缺少命名空间配置

// 建议添加 namespace 隔离不同环境Propertiesproperties=newProperties();properties.put("serverAddr","localhost:8848");properties.put("namespace","dev");ConfigFactory.createConfigService(properties);

3. 错误处理

• 当前代码未处理 Nacos 连接失败的情况
• 建议添加重试机制和降级策略

这套代码提供了 Sentinel 与 Nacos 集成的标准实现模板，是实现规则持久化的关键组件。通过这种设计，Dashboard 的规则修改可以持久化到 Nacos，并自动同步到所有客户端应用。