Add Consul DataSource integration module (#979)

sentinel-extension/pom.xml

@@ -19,6 +19,7 @@
         <module>sentinel-datasource-redis</module>
         <module>sentinel-annotation-aspectj</module>
         <module>sentinel-parameter-flow-control</module>
+        <module>sentinel-datasource-consul</module>
     </modules>
 
 </project>

sentinel-extension/sentinel-datasource-consul/pom.xml

@@ -0,0 +1,49 @@
+<?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-extension</artifactId>
+        <groupId>com.alibaba.csp</groupId>
+        <version>1.7.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>sentinel-datasource-consul</artifactId>
+    <packaging>jar</packaging>
+
+    <properties>
+        <java.source.version>1.8</java.source.version>
+        <java.target.version>1.8</java.target.version>
+        <consul.version>1.4.2</consul.version>
+        <consul.process.version>2.0.0</consul.process.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.alibaba.csp</groupId>
+            <artifactId>sentinel-datasource-extension</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.ecwid.consul</groupId>
+            <artifactId>consul-api</artifactId>
+            <version>${consul.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.pszymczyk.consul</groupId>
+            <artifactId>embedded-consul</artifactId>
+            <version>${consul.process.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.alibaba</groupId>
+            <artifactId>fastjson</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>

sentinel-extension/sentinel-datasource-consul/src/main/java/com/alibaba/csp/sentinel/datasource/consul/ConsulDataSource.java

@@ -0,0 +1,175 @@
+package com.alibaba.csp.sentinel.datasource.consul;
+
+import com.alibaba.csp.sentinel.concurrent.NamedThreadFactory;
+import com.alibaba.csp.sentinel.datasource.AbstractDataSource;
+import com.alibaba.csp.sentinel.datasource.Converter;
+import com.alibaba.csp.sentinel.log.RecordLog;
+import com.alibaba.csp.sentinel.util.AssertUtil;
+import com.ecwid.consul.v1.ConsulClient;
+import com.ecwid.consul.v1.QueryParams;
+import com.ecwid.consul.v1.Response;
+import com.ecwid.consul.v1.kv.model.GetValue;
+
+import java.util.concurrent.*;
+
+import static java.util.concurrent.Executors.newSingleThreadExecutor;
+
+/**
+ * <p>
+ * A read-only {@code DataSource} with Consul backend.
+ * <p>
+ * <p>
+ * The data source first initial rules from a Consul during initialization.
+ * Then it start a watcher to observe the updates of rule date and update to memory.
+ *
+ * Consul do not provide http api to watch the update of KV，so it use a long polling and
+ * <a href="https://www.consul.io/api/features/blocking.html">blocking queries</a> of the Consul's feature
+ * to watch and update value easily.When Querying data by index will blocking until change or timeout. If
+ * the index of the current query is larger than before, it means that the data has changed.
+ * </p>
+ *
+ * @author wavesZh
+ */
+public class ConsulDataSource<T> extends AbstractDataSource<String, T> {
+
+    private static final int DEFAULT_PORT = 8500;
+
+    private final ConsulClient client;
+
+    private final String address;
+
+    private String ruleKey;
+    /**
+     * Record the data's index in Consul to watch the change.
+     * If lastIndex is smaller than the index of next query, it means that rule data has updated.
+     */
+    private volatile long lastIndex;
+    /**
+     * Request of query will hang until timeout(ms) or get updated value.
+     */
+    private int watchTimeout;
+
+    private ConsulKVWatcher watcher = new ConsulKVWatcher();
+
+    private ExecutorService watcherService = newSingleThreadExecutor(
+            new NamedThreadFactory("sentinel-consul-ds-update", true));
+
+    public ConsulDataSource(Converter<String, T> parser, String host, String ruleKey, int watchTimeout) {
+        this(host, DEFAULT_PORT, ruleKey, watchTimeout, parser);
+    }
+
+    /**
+     * Constructor of {@code ConsulDataSource}.
+     * @param parser          customized data parser, cannot be empty
+     * @param host            consul agent host
+     * @param port            consul agent port
+     * @param ruleKey         data key in Consul
+     * @param watchTimeout    request for querying data will be blocked until new data or timeout. The unit is ms
+     */
+    public ConsulDataSource(String host, int port, String ruleKey, int watchTimeout, Converter<String, T> parser) {
+        super(parser);
+        AssertUtil.notNull(host, "Consul host can not be null");
+        AssertUtil.notEmpty(ruleKey, "Consul ruleKey can not be empty");
+        this.client = new ConsulClient(host, port);
+        this.address = host + ":" + port;
+        this.ruleKey = ruleKey;
+        this.watchTimeout = watchTimeout;
+        loadInitialConfig();
+        startKVWatcher();
+    }
+
+    private void startKVWatcher() {
+        watcherService.submit(watcher);
+    }
+
+    private void loadInitialConfig() {
+        try {
+            T newValue = loadConfig();
+            if (newValue == null) {
+                RecordLog.warn("[ConsulDataSource] WARN: initial config is null, you may have to check your data source");
+            }
+            getProperty().updateValue(newValue);
+        } catch (Exception ex) {
+            RecordLog.warn("[ConsulDataSource] Error when loading initial config", ex);
+        }
+    }
+
+    @Override
+    public String readSource() throws Exception {
+        if (this.client == null) {
+            throw new IllegalStateException("Consul has not been initialized or error occurred");
+        }
+        Response<GetValue> response = getValueImmediately(ruleKey);
+        if (response != null) {
+            GetValue value = response.getValue();
+            lastIndex = response.getConsulIndex();
+            return value != null ? value.getDecodedValue() : null;
+        }
+        return null;
+    }
+
+    @Override
+    public void close() throws Exception {
+        watcher.stop();
+        watcherService.shutdown();
+    }
+
+    private class ConsulKVWatcher implements Runnable {
+        private boolean running = true;
+        @Override
+        public void run() {
+            while (running) {
+                // It will be blocked until watchTimeout(ms) if rule data has no update.
+                Response<GetValue> response = getValue(ruleKey, lastIndex, watchTimeout / 1000);
+                if (response == null) {
+                    try {
+                        TimeUnit.MILLISECONDS.sleep(watchTimeout);
+                    } catch (InterruptedException e) {
+                    }
+                    continue;
+                }
+                GetValue getValue = response.getValue();
+                Long currentIndex = response.getConsulIndex();
+                if (currentIndex == null || currentIndex <= lastIndex) {
+                    continue;
+                }
+                lastIndex = currentIndex;
+                if (getValue != null) {
+                    String newValue = getValue.getDecodedValue();
+                    getProperty().updateValue(parser.convert(newValue));
+                    RecordLog.info(String.format("[ConsulDataSource] New property value received for (%s, %s): %s",
+                            address, ruleKey, newValue));
+                }
+            }
+        }
+
+        private void stop() {
+            running = false;
+        }
+    }
+
+    /**
+     * get data from Consul immediately.
+     *
+     * @param key data key in Consul
+     */
+    public Response<GetValue> getValueImmediately(String key) {
+        return getValue(key, -1, -1);
+    }
+    /**
+     * get data from Consul.
+     *
+     * @param key data key in Consul
+     * @param index the index of data in Consul.
+     * @param waitTime time(second) for waiting get updated value.
+     */
+    private Response<GetValue> getValue(String key, long index, long waitTime) {
+        try {
+            return client.getKVValue(key, new QueryParams(waitTime, index));
+        } catch (Throwable t) {
+            RecordLog.warn("fail to get value for key: " + key);
+        }
+        return null;
+    }
+
+}

sentinel-extension/sentinel-datasource-consul/src/test/java/com/alibaba/csp/sentinel/datasource/consul/ConsulDataSourceTest.java

@@ -0,0 +1,98 @@
+package com.alibaba.csp.sentinel.datasource.consul;
+
+
+import com.alibaba.csp.sentinel.datasource.Converter;
+import com.alibaba.csp.sentinel.datasource.ReadableDataSource;
+import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
+import com.alibaba.csp.sentinel.slots.block.flow.FlowRuleManager;
+import com.alibaba.fastjson.JSON;
+import com.alibaba.fastjson.TypeReference;
+import com.ecwid.consul.v1.ConsulClient;
+import com.ecwid.consul.v1.Response;
+import com.pszymczyk.consul.ConsulProcess;
+import com.pszymczyk.consul.ConsulStarterBuilder;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.TimeUnit;
+
+
+public class ConsulDataSourceTest {
+    private ConsulProcess consul;
+
+    private ConsulClient client;
+
+    private ReadableDataSource<String, List<FlowRule>> consulDataSource;
+
+    private String host = "127.0.0.1";
+
+    private int port;
+
+    private String ruleKey = "sentinel.rules.flow.ruleKey";
+
+    private int waitTimeout = 60;
+
+    private List<FlowRule> rules;
+
+    @Before
+    public void init() {
+        this.consul = ConsulStarterBuilder.consulStarter()
+                .build()
+                .start();
+        this.port = consul.getHttpPort();
+        client = new ConsulClient(host, port);
+        Converter<String, List<FlowRule>> flowConfigParser = buildFlowConfigParser();
+        String flowRulesJson =
+                "[{\"resource\":\"test\", \"limitApp\":\"default\", \"grade\":1, \"count\":\"0.0\", \"strategy\":0, "
+                        + "\"refResource\":null, "
+                        +
+                        "\"controlBehavior\":0, \"warmUpPeriodSec\":10, \"maxQueueingTimeMs\":500, \"controller\":null}]";
+        initConsulRuleData(flowRulesJson);
+        rules = flowConfigParser.convert(flowRulesJson);
+        consulDataSource = new ConsulDataSource<>(host, port, ruleKey, waitTimeout, flowConfigParser);
+        FlowRuleManager.register2Property(consulDataSource.getProperty());
+    }
+
+    @After
+    public void clean() throws Exception {
+        if (consulDataSource != null) {
+            consulDataSource.close();
+        }
+        if (consul != null) {
+            consul.close();
+        }
+    }
+
+
+    @Test
+    public void testConsulDataSourceWhenInit() {
+        List<FlowRule> rules = FlowRuleManager.getRules();
+        Assert.assertEquals(this.rules, rules);
+    }
+
+
+    @Test
+    public void testConsulDataSourceWhenUpdate() throws InterruptedException {
+        rules.get(0).setMaxQueueingTimeMs(new Random().nextInt());
+        client.setKVValue(ruleKey, JSON.toJSONString(rules));
+        TimeUnit.MILLISECONDS.sleep(waitTimeout);
+        List<FlowRule> rules = FlowRuleManager.getRules();
+        Assert.assertEquals(this.rules, rules);
+    }
+
+
+    private Converter<String, List<FlowRule>> buildFlowConfigParser() {
+        return source -> JSON.parseObject(source, new TypeReference<List<FlowRule>>() {});
+    }
+
+    private void initConsulRuleData(String flowRulesJson) {
+        Response<Boolean> response = client.setKVValue(ruleKey, flowRulesJson);
+        Assert.assertEquals(Boolean.TRUE,  response.getValue());
+    }
+
+
+}