dashboard: Add ZooKeeper flow rule dynamic publisher sample (#714)

sentinel-dashboard/pom.xml

@@ -16,6 +16,7 @@
         <maven.compiler.source>1.8</maven.compiler.source>
         <maven.compiler.target>1.8</maven.compiler.target>
         <spring.boot.version>2.0.5.RELEASE</spring.boot.version>
+        <curator.version>4.0.1</curator.version>
     </properties>
 
     <dependencies>
@@ -106,6 +107,14 @@
             <scope>test</scope>
         </dependency>
 
+        <!--for Zookeeper rule publisher sample-->
+        <dependency>
+            <groupId>org.apache.curator</groupId>
+            <artifactId>curator-recipes</artifactId>
+            <version>${curator.version}</version>
+            <scope>test</scope>
+        </dependency>
+
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>

sentinel-dashboard/src/test/java/com/alibaba/csp/sentinel/dashboard/rule/zookeeper/FlowRuleZookeeperProvider.java

@@ -0,0 +1,47 @@
+/*
+ * 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.
+ */
+package com.alibaba.csp.sentinel.dashboard.rule.zookeeper;
+
+import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.FlowRuleEntity;
+import com.alibaba.csp.sentinel.dashboard.rule.DynamicRuleProvider;
+import com.alibaba.csp.sentinel.datasource.Converter;
+import org.apache.curator.framework.CuratorFramework;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@Component("flowRuleZookeeperPublisher")
+public class FlowRuleZookeeperProvider implements DynamicRuleProvider<List<FlowRuleEntity>> {
+
+    @Autowired
+    private CuratorFramework zkClient;
+    @Autowired
+    private Converter<String, List<FlowRuleEntity>> converter;
+
+    @Override
+    public List<FlowRuleEntity> getRules(String appName) throws Exception {
+        String zkPath = ZookeeperConfigUtil.getPath(appName);
+        byte[] bytes = zkClient.getData().forPath(zkPath);
+        if (null == bytes || bytes.length == 0) {
+            return new ArrayList<>();
+        }
+        String s = new String(bytes);
+
+        return converter.convert(s);
+    }
+}

sentinel-dashboard/src/test/java/com/alibaba/csp/sentinel/dashboard/rule/zookeeper/FlowRuleZookeeperPublisher.java

@@ -0,0 +1,50 @@
+/*
+ * 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.
+ */
+package com.alibaba.csp.sentinel.dashboard.rule.zookeeper;
+
+import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.FlowRuleEntity;
+import com.alibaba.csp.sentinel.dashboard.rule.DynamicRulePublisher;
+import com.alibaba.csp.sentinel.datasource.Converter;
+import com.alibaba.csp.sentinel.util.AssertUtil;
+import org.apache.curator.framework.CuratorFramework;
+import org.apache.zookeeper.CreateMode;
+import org.apache.zookeeper.data.Stat;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+import org.springframework.util.CollectionUtils;
+
+import java.util.List;
+
+@Component("flowRuleZookeeperPublisher")
+public class FlowRuleZookeeperPublisher implements DynamicRulePublisher<List<FlowRuleEntity>> {
+    @Autowired
+    private CuratorFramework zkClient;
+    @Autowired
+    private Converter<List<FlowRuleEntity>, String> converter;
+
+    @Override
+    public void publish(String app, List<FlowRuleEntity> rules) throws Exception {
+        AssertUtil.notEmpty(app, "app name cannot be empty");
+
+        String path = ZookeeperConfigUtil.getPath(app);
+        Stat stat = zkClient.checkExists().forPath(path);
+        if (stat == null) {
+            zkClient.create().creatingParentContainersIfNeeded().withMode(CreateMode.PERSISTENT).forPath(path, null);
+        }
+        byte[] data = CollectionUtils.isEmpty(rules) ? "".getBytes() : converter.convert(rules).getBytes();
+        zkClient.setData().forPath(path, data);
+    }
+}

sentinel-dashboard/src/test/java/com/alibaba/csp/sentinel/dashboard/rule/zookeeper/ZookeeperConfig.java

@@ -0,0 +1,51 @@
+/*
+ * 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.
+ */
+package com.alibaba.csp.sentinel.dashboard.rule.zookeeper;
+
+import com.alibaba.csp.sentinel.dashboard.datasource.entity.rule.FlowRuleEntity;
+import com.alibaba.csp.sentinel.datasource.Converter;
+import com.alibaba.fastjson.JSON;
+import org.apache.curator.framework.CuratorFramework;
+import org.apache.curator.framework.CuratorFrameworkFactory;
+import org.apache.curator.retry.ExponentialBackoffRetry;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import java.util.List;
+
+@Configuration
+public class ZookeeperConfig {
+
+    @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 CuratorFramework zkClient() {
+        CuratorFramework zkClient =
+                CuratorFrameworkFactory.newClient("127.0.0.1:2181",
+                        new ExponentialBackoffRetry(ZookeeperConfigUtil.SLEEP_TIME, ZookeeperConfigUtil.RETRY_TIMES));
+        zkClient.start();
+
+        return zkClient;
+    }
+}

sentinel-dashboard/src/test/java/com/alibaba/csp/sentinel/dashboard/rule/zookeeper/ZookeeperConfigUtil.java

@@ -0,0 +1,41 @@
+/*
+ * 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.
+ */
+package com.alibaba.csp.sentinel.dashboard.rule.zookeeper;
+
+
+import org.apache.commons.lang.StringUtils;
+
+public class ZookeeperConfigUtil {
+    public static final String RULE_ROOT_PATH = "/sentinel_rule_config";
+
+    public static final int RETRY_TIMES = 3;
+    public static final int SLEEP_TIME = 1000;
+
+    public static String getPath(String appName) {
+        StringBuilder stringBuilder = new StringBuilder(RULE_ROOT_PATH);
+
+        if (StringUtils.isBlank(appName)) {
+            return stringBuilder.toString();
+        }
+        if (appName.startsWith("/")) {
+            stringBuilder.append(appName);
+        } else {
+            stringBuilder.append("/")
+                    .append(appName);
+        }
+        return stringBuilder.toString();
+    }
+}