publish metrics in datadog, if datadog-api-key is configured

javamelody-core/src/main/java/net/bull/javamelody/Parameter.java

@@ -358,7 +358,13 @@ public enum Parameter {
 	 * URL of the <a href='https://www.influxdata.com/time-series-platform/'>InfluxDB</a> server to send metrics to,
 	 * for example: http://11.22.33.44:8086/write?db=mydb (null by default).
 	 */
-	INFLUXDB_URL("influxdb-url");
+	INFLUXDB_URL("influxdb-url"),
+
+	/**
+	 * API key of the <a href='https://www.datadoghq.com/'>Datadog</a> to send metrics,
+	 * for example: 9775a026f1ca7d1c6c5af9d94d9595a4 (null by default).
+	 */
+	DATADOG_API_KEY("datadog-api-key");
 
 	private final String code;
 

javamelody-core/src/main/java/net/bull/javamelody/internal/model/Datadog.java

@@ -0,0 +1,151 @@
+/*
+ * Copyright 2008-2017 by Emeric Vernat
+ *
+ *     This file is part of Java Melody.
+ *
+ * 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 net.bull.javamelody.internal.model;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.nio.charset.Charset;
+import java.text.DecimalFormat;
+import java.text.DecimalFormatSymbols;
+import java.util.Locale;
+
+import net.bull.javamelody.Parameter;
+import net.bull.javamelody.internal.common.LOG;
+
+/**
+ * Publish chart data to <a href='https://www.datadoghq.com/'>Datadog</a>.
+ * @author Emeric Vernat
+ */
+class Datadog extends MetricsPublisher {
+	private static final String BEGIN_SERIES = "{ \"series\" : [";
+	private static final String END_SERIES = "\n]}";
+	private final URL datadogUrl;
+	private final String prefix;
+	private final String hostAndTags;
+
+	private final DecimalFormat decimalFormat = new DecimalFormat("0.00",
+			DecimalFormatSymbols.getInstance(Locale.US));
+	private final ByteArrayOutputStream buffer = new ByteArrayOutputStream();
+	private final Writer bufferWriter = new OutputStreamWriter(buffer, Charset.forName("UTF-8"));
+
+	Datadog(String datadogApiKey, String prefix, String hostAndTags) {
+		super();
+		assert datadogApiKey != null;
+		assert prefix != null;
+		assert hostAndTags != null;
+		try {
+			this.datadogUrl = new URL(
+					"https://app.datadoghq.com/api/v1/series?api_key=" + datadogApiKey);
+		} catch (final MalformedURLException e) {
+			throw new IllegalArgumentException(e);
+		}
+		this.prefix = prefix;
+		this.hostAndTags = hostAndTags;
+		try {
+			bufferWriter.append(BEGIN_SERIES);
+		} catch (final IOException e) {
+			// can not happen
+			throw new IllegalStateException(e);
+		}
+	}
+
+	static Datadog getInstance(String contextPath, String hostName) {
+		final String datadogApiKey = Parameter.DATADOG_API_KEY.getValue();
+		if (datadogApiKey != null) {
+			assert contextPath != null;
+			assert hostName != null;
+			// contextPath est du genre "/testapp"
+			// hostName est du genre "www.host.com"
+
+			final String prefix = "javamelody.";
+			String application = contextPath;
+			if (application.isEmpty()) {
+				// tag value must not be empty
+				application = "/";
+			}
+			final String hostAndTags = "\"host\":\"" + hostName + "\",\"tags\":[\"application\":\""
+					+ application + "\"]";
+			return new Datadog(datadogApiKey, prefix, hostAndTags);
+		}
+		return null;
+	}
+
+	@Override
+	synchronized void addValue(String metric, double value) throws IOException {
+		/*
+		https://docs.datadoghq.com/api/
+		json example for timestamp now, host and tags are optional.
+		"{ \"series\" :
+		        [{\"metric\":\"page.views\",
+		          \"points\":1000,
+		          \"host\":\"myhost.example.com\",
+		          \"tags\":[\"version:1\"]}
+		        ]
+		}"
+		*/
+		bufferWriter.append("\n{\"metric\":\"").append(prefix).append(metric).append("\",");
+		bufferWriter.append("\"points\":").append(decimalFormat.format(value)).append(",");
+		bufferWriter.append(hostAndTags);
+		bufferWriter.append("}");
+	}
+
+	@Override
+	synchronized void send() throws IOException {
+		try {
+			bufferWriter.append(END_SERIES);
+			bufferWriter.flush();
+			final HttpURLConnection connection = (HttpURLConnection) datadogUrl.openConnection();
+			connection.setConnectTimeout(20000);
+			connection.setReadTimeout(60000);
+			connection.setRequestMethod("POST");
+			connection.setRequestProperty("Content-Type", "application/json");
+			connection.setDoOutput(true);
+			final OutputStream outputStream = connection.getOutputStream();
+			buffer.writeTo(outputStream);
+			outputStream.flush();
+
+			final int status = connection.getResponseCode();
+			if (status >= HttpURLConnection.HTTP_BAD_REQUEST) {
+				final ByteArrayOutputStream errorOutputStream = new ByteArrayOutputStream();
+				TransportFormat.pump(connection.getErrorStream(), errorOutputStream);
+				final String msg = "Error connecting to Datadog (" + status + "): "
+						+ errorOutputStream.toString("UTF-8");
+				LOG.warn(msg, new IOException(msg));
+			}
+			connection.disconnect();
+		} catch (Exception e) {
+			LOG.warn(e.toString(), e);
+		} finally {
+			// finally to be sure to not keep too much data in buffer
+			// including when the http url can't connect
+			buffer.reset();
+			bufferWriter.append(BEGIN_SERIES);
+		}
+	}
+
+	@Override
+	void stop() {
+		// nothing
+	}
+}

javamelody-core/src/main/java/net/bull/javamelody/internal/model/MetricsPublisher.java

@@ -43,6 +43,7 @@ static List<MetricsPublisher> getMetricsPublishers(
 		final Graphite graphite = Graphite.getInstance(contextPath, hosts);
 		final CloudWatch cloudWatch = CloudWatch.getInstance(contextPath, hosts);
 		final InfluxDB influxDb = InfluxDB.getInstance(contextPath, hosts);
+		final Datadog datadog = Datadog.getInstance(contextPath, hosts);
 		if (graphite != null) {
 			metricsPublishers.add(graphite);
 		}
@@ -52,6 +53,9 @@ static List<MetricsPublisher> getMetricsPublishers(
 		if (influxDb != null) {
 			metricsPublishers.add(influxDb);
 		}
+		if (datadog != null) {
+			metricsPublishers.add(datadog);
+		}
 		if (metricsPublishers.isEmpty()) {
 			return Collections.emptyList();
 		}