Add an ApiCommandHandler to list all available commands and description (#491)

* Add a ApiCommandHandler which fetch all registered CommandHandlers so that user can get all available CommandHandlers by request /api
* Add a customized CommandHandler demo

sentinel-cluster/sentinel-cluster-client-default/src/main/java/com/alibaba/csp/sentinel/command/handler/FetchClusterClientConfigHandler.java

@@ -29,7 +29,7 @@ import com.alibaba.fastjson.JSON;
  * @author Eric Zhao
  * @since 1.4.0
  */
-@CommandMapping(name = "cluster/client/fetchConfig")
+@CommandMapping(name = "cluster/client/fetchConfig", desc = "get cluster client config")
 public class FetchClusterClientConfigHandler implements CommandHandler<String> {
 
     @Override

sentinel-cluster/sentinel-cluster-client-default/src/main/java/com/alibaba/csp/sentinel/command/handler/ModifyClusterClientConfigHandler.java

@@ -33,7 +33,7 @@ import com.alibaba.fastjson.JSON;
  * @author Eric Zhao
  * @since 1.4.0
  */
-@CommandMapping(name = "cluster/client/modifyConfig")
+@CommandMapping(name = "cluster/client/modifyConfig", desc = "modify cluster client config")
 public class ModifyClusterClientConfigHandler implements CommandHandler<String> {
 
     @Override

sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/server/command/handler/FetchClusterFlowRulesCommandHandler.java

@@ -27,7 +27,7 @@ import com.alibaba.fastjson.JSON;
  * @author Eric Zhao
  * @since 1.4.0
  */
-@CommandMapping(name = "cluster/server/flowRules")
+@CommandMapping(name = "cluster/server/flowRules", desc = "get cluster flow rules")
 public class FetchClusterFlowRulesCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/server/command/handler/FetchClusterMetricCommandHandler.java

@@ -27,7 +27,7 @@ import com.alibaba.fastjson.JSON;
  * @author Eric Zhao
  * @since 1.4.1
  */
-@CommandMapping(name = "cluster/server/metricList")
+@CommandMapping(name = "cluster/server/metricList", desc = "get cluster server metrics")
 public class FetchClusterMetricCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/server/command/handler/FetchClusterParamFlowRulesCommandHandler.java

@@ -27,7 +27,7 @@ import com.alibaba.fastjson.JSON;
  * @author Eric Zhao
  * @since 1.4.0
  */
-@CommandMapping(name = "cluster/server/paramRules")
+@CommandMapping(name = "cluster/server/paramRules", desc = "get cluster server param flow rules")
 public class FetchClusterParamFlowRulesCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/server/command/handler/FetchClusterServerConfigHandler.java

@@ -29,7 +29,7 @@ import com.alibaba.fastjson.JSONObject;
  * @author Eric Zhao
  * @since 1.4.0
  */
-@CommandMapping(name = "cluster/server/fetchConfig")
+@CommandMapping(name = "cluster/server/fetchConfig", desc = "get cluster server config")
 public class FetchClusterServerConfigHandler implements CommandHandler<String> {
 
     @Override

sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/server/command/handler/FetchClusterServerInfoCommandHandler.java

@@ -35,7 +35,7 @@ import com.alibaba.fastjson.JSONObject;
  * @author Eric Zhao
  * @since 1.4.0
  */
-@CommandMapping(name = "cluster/server/info")
+@CommandMapping(name = "cluster/server/info", desc = "get cluster server info")
 public class FetchClusterServerInfoCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/server/command/handler/ModifyClusterFlowRulesCommandHandler.java

@@ -32,7 +32,7 @@ import com.alibaba.fastjson.JSONArray;
  * @author Eric Zhao
  * @since 1.4.0
  */
-@CommandMapping(name = "cluster/server/modifyFlowRules")
+@CommandMapping(name = "cluster/server/modifyFlowRules", desc = "modify cluster flow rules")
 public class ModifyClusterFlowRulesCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/server/command/handler/ModifyClusterParamFlowRulesCommandHandler.java

@@ -32,7 +32,7 @@ import com.alibaba.fastjson.JSONArray;
  * @author Eric Zhao
  * @since 1.4.0
  */
-@CommandMapping(name = "cluster/server/modifyParamRules")
+@CommandMapping(name = "cluster/server/modifyParamRules", desc = "modify cluster param flow rules")
 public class ModifyClusterParamFlowRulesCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/server/command/handler/ModifyClusterServerFlowConfigHandler.java

@@ -32,7 +32,7 @@ import com.alibaba.fastjson.JSON;
  * @author Eric Zhao
  * @since 1.4.0
  */
-@CommandMapping(name = "cluster/server/modifyFlowConfig")
+@CommandMapping(name = "cluster/server/modifyFlowConfig", desc = "modify cluster server flow config")
 public class ModifyClusterServerFlowConfigHandler implements CommandHandler<String> {
 
     @Override

sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/server/command/handler/ModifyClusterServerTransportConfigHandler.java

@@ -27,7 +27,7 @@ import com.alibaba.csp.sentinel.util.StringUtil;
  * @author Eric Zhao
  * @since 1.4.0
  */
-@CommandMapping(name = "cluster/server/modifyTransportConfig")
+@CommandMapping(name = "cluster/server/modifyTransportConfig", desc = "modify cluster server transport config")
 public class ModifyClusterServerTransportConfigHandler implements CommandHandler<String> {
 
     @Override

sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/server/command/handler/ModifyServerNamespaceSetHandler.java

@@ -33,7 +33,7 @@ import com.alibaba.fastjson.TypeReference;
  * @author Eric Zhao
  * @since 1.4.0
  */
-@CommandMapping(name = "cluster/server/modifyNamespaceSet")
+@CommandMapping(name = "cluster/server/modifyNamespaceSet", desc = "modify server namespace set")
 public class ModifyServerNamespaceSetHandler implements CommandHandler<String> {
 
     @Override

sentinel-demo/pom.xml

@@ -29,6 +29,7 @@
         <module>sentinel-demo-parameter-flow-control</module>
         <module>sentinel-demo-slot-chain-spi</module>
         <module>sentinel-demo-cluster</module>
+        <module>sentinel-demo-command-handler</module>
     </modules>
 
     <dependencies>

sentinel-demo/sentinel-demo-command-handler/pom.xml

@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>sentinel-demo</artifactId>
+        <groupId>com.alibaba.csp</groupId>
+        <version>1.4.2-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>sentinel-demo-command-handler</artifactId>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.alibaba.csp</groupId>
+            <artifactId>sentinel-cluster-client-default</artifactId>
+            <version>1.4.2-SNAPSHOT</version>
+        </dependency>
+        <dependency>
+            <groupId>com.alibaba.csp</groupId>
+            <artifactId>sentinel-cluster-server-default</artifactId>
+            <version>1.4.2-SNAPSHOT</version>
+        </dependency>
+        <dependency>
+            <groupId>com.alibaba.csp</groupId>
+            <artifactId>sentinel-transport-simple-http</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+            <version>1.5.17.RELEASE</version>
+        </dependency>
+    </dependencies>
+</project>

sentinel-demo/sentinel-demo-command-handler/src/main/java/com/alibaba/csp/sentinel/demo/commandhandler/Application.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 1999-2019 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.
+ */
+package com.alibaba.csp.sentinel.demo.commandhandler;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+/**
+ * @author houyi
+ **/
+@SpringBootApplication(scanBasePackages = {"com.alibaba.csp.sentinel"})
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+
+}

sentinel-demo/sentinel-demo-command-handler/src/main/java/com/alibaba/csp/sentinel/demo/commandhandler/EchoCommandHandler.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 1999-2019 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.
+ */
+package com.alibaba.csp.sentinel.demo.commandhandler;
+
+import com.alibaba.csp.sentinel.command.CommandHandler;
+import com.alibaba.csp.sentinel.command.CommandRequest;
+import com.alibaba.csp.sentinel.command.CommandResponse;
+import com.alibaba.csp.sentinel.command.annotation.CommandMapping;
+
+/**
+ * Customized CommandHandler
+ * This Class is a demo shows how to create a customized CommandHandler
+ * <ul>
+ *     <li>1.Create a class which implements the {@link CommandHandler} interface </li>
+ *     <li>2.Use a {@link CommandMapping} to specify the url and desc of your CommandHandler </li>
+ *     <li>3.Implement your own handle method </li>
+ *     <li>4.Add your CommandHandler in com.alibaba.csp.sentinel.command.CommandHandler file which is stored in resources/META-INF/services/ </li>
+ * </ul>
+ * @author houyi
+ **/
+@CommandMapping(name = "echo", desc = "echo service")
+public class EchoCommandHandler implements CommandHandler<String> {
+
+    @Override
+    public CommandResponse<String> handle(CommandRequest request) {
+        String name = request.getParam("name");
+        if(name==null || name.trim().length()==0){
+            return CommandResponse.ofSuccess("Tell us what's your name by submit a name parameter");
+        }
+        return CommandResponse.ofSuccess("Hello: "+name);
+    }
+
+}

sentinel-demo/sentinel-demo-command-handler/src/main/java/com/alibaba/csp/sentinel/demo/commandhandler/MainController.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 1999-2019 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.
+ */
+package com.alibaba.csp.sentinel.demo.commandhandler;
+
+import com.alibaba.csp.sentinel.SphU;
+import com.alibaba.csp.sentinel.slots.block.BlockException;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.ResponseBody;
+
+/**
+ * @author houyi
+ **/
+@Controller
+public class MainController {
+
+    /**
+     * init sentinel
+     * @return pass or block
+     */
+    @GetMapping("/init")
+    public @ResponseBody
+    String init() {
+        String retVal;
+        String resource = "init";
+        try{
+            SphU.entry(resource);
+            retVal = "pass";
+        }catch (BlockException e){
+            retVal = "block";
+        }
+        return retVal;
+    }
+
+}

sentinel-demo/sentinel-demo-command-handler/src/main/resources/META-INF/services/com.alibaba.csp.sentinel.command.CommandHandler

@@ -0,0 +1 @@
+com.alibaba.csp.sentinel.demo.commandhandler.EchoCommandHandler

sentinel-extension/sentinel-parameter-flow-control/src/main/java/com/alibaba/csp/sentinel/command/handler/FetchTopParamsCommandHandler.java

@@ -30,7 +30,7 @@ import com.alibaba.fastjson.JSON;
  * @author Eric Zhao
  * @since 0.2.0
  */
-@CommandMapping(name = "topParams")
+@CommandMapping(name = "topParams", desc = "get topN param in specified resource, accept param: res={resourceName}&idx={paramIndex}&n={topN}")
 public class FetchTopParamsCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-extension/sentinel-parameter-flow-control/src/main/java/com/alibaba/csp/sentinel/command/handler/GetParamFlowRulesCommandHandler.java

@@ -26,7 +26,7 @@ import com.alibaba.fastjson.JSON;
  * @author Eric Zhao
  * @since 0.2.0
  */
-@CommandMapping(name = "getParamFlowRules")
+@CommandMapping(name = "getParamFlowRules", desc = "get param flow rules")
 public class GetParamFlowRulesCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-extension/sentinel-parameter-flow-control/src/main/java/com/alibaba/csp/sentinel/command/handler/ModifyParamFlowRulesCommandHandler.java

@@ -33,7 +33,7 @@ import com.alibaba.fastjson.JSONArray;
  * @author Eric Zhao
  * @since 0.2.0
  */
-@CommandMapping(name = "setParamFlowRules")
+@CommandMapping(name = "setParamFlowRules", desc = "set param flow rules, accept param: data={paramFlowRule Json}")
 public class ModifyParamFlowRulesCommandHandler implements CommandHandler<String> {
 
     private static WritableDataSource<List<ParamFlowRule>> paramFlowWds = null;

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/annotation/CommandMapping.java

@@ -15,11 +15,7 @@
  */
 package com.alibaba.csp.sentinel.command.annotation;
 
-import java.lang.annotation.Documented;
-import java.lang.annotation.ElementType;
-import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
-import java.lang.annotation.Target;
+import java.lang.annotation.*;
 
 /**
  * @author Eric Zhao
@@ -30,4 +26,7 @@ import java.lang.annotation.Target;
 public @interface CommandMapping {
 
     String name();
+
+    String desc();
+
 }

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/ApiCommandHandler.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 1999-2019 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.
+ */
+package com.alibaba.csp.sentinel.command.handler;
+
+import com.alibaba.csp.sentinel.command.CommandHandler;
+import com.alibaba.csp.sentinel.command.CommandHandlerProvider;
+import com.alibaba.csp.sentinel.command.CommandRequest;
+import com.alibaba.csp.sentinel.command.CommandResponse;
+import com.alibaba.csp.sentinel.command.annotation.CommandMapping;
+import com.alibaba.fastjson.JSONArray;
+import com.alibaba.fastjson.JSONObject;
+
+import java.util.Map;
+
+/**
+ * <p>
+ * List all available command handlers by request: </br>
+ * {@code curl http://localhost:8719/api}
+ * </p>
+ * @author houyi
+ **/
+@CommandMapping(name = "api", desc = "get all available command handlers")
+public class ApiCommandHandler implements CommandHandler<String> {
+
+    @Override
+    public CommandResponse<String> handle(CommandRequest request) {
+        Map<String, CommandHandler> handlers = CommandHandlerProvider.getInstance().namedHandlers();
+        JSONArray array = new JSONArray();
+        if (handlers.isEmpty()) {
+            return CommandResponse.ofSuccess(array.toJSONString());
+        }
+        for (CommandHandler handler : handlers.values()) {
+            CommandMapping commandMapping = handler.getClass().getAnnotation(CommandMapping.class);
+            if (commandMapping == null) {
+                continue;
+            }
+            String api = commandMapping.name();
+            String desc = commandMapping.desc();
+            JSONObject obj = new JSONObject();
+            obj.put("url", "/" + api);
+            obj.put("desc", desc);
+            array.add(obj);
+        }
+        return CommandResponse.ofSuccess(array.toJSONString());
+    }
+
+}

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/BasicInfoCommandHandler.java

@@ -26,7 +26,7 @@ import com.alibaba.csp.sentinel.util.HostNameUtil;
  *
  * @author Eric Zhao
  */
-@CommandMapping(name = "basicInfo")
+@CommandMapping(name = "basicInfo", desc = "get sentinel config info")
 public class BasicInfoCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/FetchActiveRuleCommandHandler.java

@@ -28,7 +28,7 @@ import com.alibaba.fastjson.JSON;
 /**
  * @author jialiang.linjl
  */
-@CommandMapping(name = "getRules")
+@CommandMapping(name = "getRules", desc = "get all active rules by type, request param: type={ruleType}")
 public class FetchActiveRuleCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/FetchClusterNodeByIdCommandHandler.java

@@ -28,7 +28,7 @@ import com.alibaba.fastjson.JSON;
 /**
  * @author qinan.qn
  */
-@CommandMapping(name = "clusterNodeById")
+@CommandMapping(name = "clusterNodeById", desc = "get clusterNode VO by id, request param: id={resourceName}")
 public class FetchClusterNodeByIdCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/FetchClusterNodeHumanCommandHandler.java

@@ -29,7 +29,7 @@ import com.alibaba.csp.sentinel.slots.clusterbuilder.ClusterBuilderSlot;
 /**
  * @author qinan.qn
  */
-@CommandMapping(name = "cnode")
+@CommandMapping(name = "cnode", desc = "get clusterNode metrics by id, request param: id={resourceName}")
 public class FetchClusterNodeHumanCommandHandler implements CommandHandler<String> {
 
     private final static String FORMAT = "%-4s%-80s%-10s%-10s%-10s%-11s%-9s%-6s%-10s%-11s%-9s%-11s";

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/FetchJsonTreeCommandHandler.java

@@ -32,7 +32,7 @@ import com.alibaba.fastjson.JSON;
 /**
  * @author leyou
  */
-@CommandMapping(name = "jsonTree")
+@CommandMapping(name = "jsonTree", desc = "get tree node VO start from root node")
 public class FetchJsonTreeCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/FetchOriginCommandHandler.java

@@ -29,7 +29,7 @@ import com.alibaba.csp.sentinel.slots.clusterbuilder.ClusterBuilderSlot;
 /**
  * @author qinan.qn
  */
-@CommandMapping(name = "origin")
+@CommandMapping(name = "origin", desc = "get origin clusterNode by id, request param: id={resourceName}")
 public class FetchOriginCommandHandler implements CommandHandler<String> {
 
     private final static String FORMAT = "%-4s%-80s%-10s%-10s%-11s%-9s%-6s%-10s%-11s%-9s";

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/FetchSimpleClusterNodeCommandHandler.java

@@ -32,7 +32,7 @@ import com.alibaba.fastjson.JSONArray;
 /**
  * @author jialiang.linjl
  */
-@CommandMapping(name = "clusterNode")
+@CommandMapping(name = "clusterNode", desc = "get all clusterNode VO, use type=notZero to ignore those nodes with totalRequest <=0")
 public class FetchSimpleClusterNodeCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/FetchSystemStatusCommandHandler.java

@@ -28,7 +28,7 @@ import com.alibaba.fastjson.JSONObject;
 /**
  * @author jialiang.linjl
  */
-@CommandMapping(name = "systemStatus")
+@CommandMapping(name = "systemStatus", desc = "get system status")
 public class FetchSystemStatusCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/FetchTreeCommandHandler.java

@@ -27,7 +27,7 @@ import com.alibaba.csp.sentinel.node.Node;
 /**
  * @author qinan.qn
  */
-@CommandMapping(name = "tree")
+@CommandMapping(name = "tree", desc = "get metrics in tree mode, use id to specify detailed tree root")
 public class FetchTreeCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/ModifyRulesCommandHandler.java

@@ -41,7 +41,7 @@ import static com.alibaba.csp.sentinel.transport.util.WritableDataSourceRegistry
  * @author jialiang.linjl
  * @author Eric Zhao
  */
-@CommandMapping(name = "setRules")
+@CommandMapping(name = "setRules", desc = "modify the rules, accept param: type={ruleType}&data={ruleJson}")
 public class ModifyRulesCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/OnOffGetCommandHandler.java

@@ -24,7 +24,7 @@ import com.alibaba.csp.sentinel.command.annotation.CommandMapping;
 /**
  * @author youji.zj
  */
-@CommandMapping(name = "getSwitch")
+@CommandMapping(name = "getSwitch", desc = "get sentinel switch status")
 public class OnOffGetCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/OnOffSetCommandHandler.java

@@ -25,7 +25,7 @@ import com.alibaba.csp.sentinel.Constants;
 /**
  * @author youji.zj
  */
-@CommandMapping(name = "setSwitch")
+@CommandMapping(name = "setSwitch", desc = "set sentinel switch, accept param: value={true|false}")
 public class OnOffSetCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/SendMetricCommandHandler.java

@@ -34,7 +34,7 @@ import com.alibaba.csp.sentinel.node.metric.MetricWriter;
  * @author leyou
  * @author Eric Zhao
  */
-@CommandMapping(name = "metric")
+@CommandMapping(name = "metric", desc = "get and aggregate metrics, accept param: startTime={startTime}&endTime={endTime}&maxLines={maxLines}&identify={resourceName}")
 public class SendMetricCommandHandler implements CommandHandler<String> {
 
     private MetricSearcher searcher;

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/VersionCommandHandler.java

@@ -25,7 +25,7 @@ import com.alibaba.csp.sentinel.command.annotation.CommandMapping;
  * @author jialiang.linjl
  * @author Eric Zhao
  */
-@CommandMapping(name = "version")
+@CommandMapping(name = "version", desc = "get sentinel version")
 public class VersionCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/cluster/FetchClusterModeCommandHandler.java

@@ -28,7 +28,7 @@ import com.alibaba.fastjson.JSONObject;
  * @author Eric Zhao
  * @since 1.4.0
  */
-@CommandMapping(name = "getClusterMode")
+@CommandMapping(name = "getClusterMode", desc = "get cluster mode status")
 public class FetchClusterModeCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/cluster/ModifyClusterModeCommandHandler.java

@@ -28,7 +28,7 @@ import com.alibaba.csp.sentinel.log.RecordLog;
  * @author Eric Zhao
  * @since 1.4.0
  */
-@CommandMapping(name = "setClusterMode")
+@CommandMapping(name = "setClusterMode", desc = "set cluster mode, accept param: mode={0|1} 0:client mode 1:server mode")
 public class ModifyClusterModeCommandHandler implements CommandHandler<String> {
 
     @Override

sentinel-transport/sentinel-transport-common/src/main/resources/META-INF/services/com.alibaba.csp.sentinel.command.CommandHandler

@@ -13,4 +13,5 @@ com.alibaba.csp.sentinel.command.handler.OnOffSetCommandHandler
 com.alibaba.csp.sentinel.command.handler.SendMetricCommandHandler
 com.alibaba.csp.sentinel.command.handler.VersionCommandHandler
 com.alibaba.csp.sentinel.command.handler.cluster.FetchClusterModeCommandHandler
-com.alibaba.csp.sentinel.command.handler.cluster.ModifyClusterModeCommandHandler
+com.alibaba.csp.sentinel.command.handler.cluster.ModifyClusterModeCommandHandler
+com.alibaba.csp.sentinel.command.handler.ApiCommandHandler