Add support for dw-metrics 4.x

pom.xml

@@ -77,6 +77,7 @@
         <module>prometheus-metrics-instrumentation-caffeine</module>
         <module>prometheus-metrics-instrumentation-jvm</module>
         <module>prometheus-metrics-instrumentation-dropwizard5</module>
+        <module>prometheus-metrics-instrumentation-dropwizard</module>
         <module>prometheus-metrics-instrumentation-guava</module>
         <module>prometheus-metrics-simpleclient-bridge</module>
     </modules>

prometheus-metrics-instrumentation-dropwizard/pom.xml

@@ -0,0 +1,79 @@
+<?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">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>io.prometheus</groupId>
+        <artifactId>client_java</artifactId>
+        <version>10.0.0-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>prometheus-metrics-instrumentation-dropwizard</artifactId>
+    <packaging>bundle</packaging>
+
+    <name>Prometheus Metrics Instrumentation - Dropwizard 4.x</name>
+    <description>
+        Instrumentation library for Dropwizard metrics 4.x
+    </description>
+
+    <properties>
+        <automatic.module.name>io.prometheus.metrics.instrumentation.dropwizard</automatic.module.name>
+    </properties>
+
+    <licenses>
+        <license>
+            <name>The Apache Software License, Version 2.0</name>
+            <url>http://www.apache.org/licenses/LICENSE-2.0.txt</url>
+            <distribution>repo</distribution>
+        </license>
+    </licenses>
+    <developers>
+        <developer>
+            <id>kingster</id>
+            <name>Kinshuk Bairagi</name>
+            <email>[email protected]</email>
+        </developer>
+
+    </developers>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.prometheus</groupId>
+            <artifactId>prometheus-metrics-core</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.dropwizard.metrics</groupId>
+            <artifactId>metrics-core</artifactId>
+            <version>4.2.0</version>
+            <scope>provided</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>io.prometheus</groupId>
+            <artifactId>prometheus-metrics-exporter-httpserver</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.prometheus</groupId>
+            <artifactId>prometheus-metrics-exposition-textformats</artifactId>
+            <version>${project.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.prometheus</groupId>
+            <artifactId>prometheus-metrics-instrumentation-dropwizard5</artifactId>
+            <version>${project.version}</version>
+            <scope>compile</scope>
+            <exclusions>
+                <exclusion>
+                    <groupId>io.dropwizard.metrics5</groupId>
+                    <artifactId>metrics-core</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+
+    </dependencies>
+
+</project>

prometheus-metrics-instrumentation-dropwizard/src/main/java/io/prometheus/metrics/instrumentation/dropwizard/DropwizardExports.java

@@ -0,0 +1,274 @@
+package io.prometheus.metrics.instrumentation.dropwizard;
+
+import com.codahale.metrics.Counter;
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.Histogram;
+import com.codahale.metrics.Meter;
+import com.codahale.metrics.Metric;
+import com.codahale.metrics.MetricFilter;
+import com.codahale.metrics.MetricRegistry;
+import com.codahale.metrics.Snapshot;
+import com.codahale.metrics.Timer;
+import io.prometheus.metrics.instrumentation.dropwizard5.labels.CustomLabelMapper;
+import io.prometheus.metrics.model.registry.MultiCollector;
+import io.prometheus.metrics.model.registry.PrometheusRegistry;
+import io.prometheus.metrics.model.snapshots.CounterSnapshot;
+import io.prometheus.metrics.model.snapshots.GaugeSnapshot;
+import io.prometheus.metrics.model.snapshots.MetricMetadata;
+import io.prometheus.metrics.model.snapshots.MetricSnapshot;
+import io.prometheus.metrics.model.snapshots.MetricSnapshots;
+import io.prometheus.metrics.model.snapshots.PrometheusNaming;
+import io.prometheus.metrics.model.snapshots.Quantiles;
+import io.prometheus.metrics.model.snapshots.SummarySnapshot;
+import java.util.Collections;
+import java.util.Optional;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/** Collect Dropwizard metrics from a MetricRegistry. */
+public class DropwizardExports implements MultiCollector {
+  private static final Logger logger = Logger.getLogger(DropwizardExports.class.getName());
+  private final MetricRegistry registry;
+  private final MetricFilter metricFilter;
+  private final Optional<CustomLabelMapper> labelMapper;
+
+  /**
+   * Creates a new DropwizardExports and {@link MetricFilter#ALL}.
+   *
+   * @param registry a metric registry to export in prometheus.
+   */
+  public DropwizardExports(MetricRegistry registry) {
+    super();
+    this.registry = registry;
+    this.metricFilter = MetricFilter.ALL;
+    this.labelMapper = Optional.empty();
+  }
+
+  /**
+   * Creates a new DropwizardExports with a custom {@link MetricFilter}.
+   *
+   * @param registry a metric registry to export in prometheus.
+   * @param metricFilter a custom metric filter.
+   */
+  public DropwizardExports(MetricRegistry registry, MetricFilter metricFilter) {
+    this.registry = registry;
+    this.metricFilter = metricFilter;
+    this.labelMapper = Optional.empty();
+  }
+
+  /**
+   * @param registry a metric registry to export in prometheus.
+   * @param metricFilter a custom metric filter.
+   * @param labelMapper a labelMapper to use to map labels.
+   */
+  public DropwizardExports(
+      MetricRegistry registry, MetricFilter metricFilter, CustomLabelMapper labelMapper) {
+    this.registry = registry;
+    this.metricFilter = metricFilter;
+    this.labelMapper = Optional.ofNullable(labelMapper);
+  }
+
+  private static String getHelpMessage(String metricName, Metric metric) {
+    return String.format(
+        "Generated from Dropwizard metric import (metric=%s, type=%s)",
+        metricName, metric.getClass().getName());
+  }
+
+  private MetricMetadata getMetricMetaData(String metricName, Metric metric) {
+    String name = labelMapper.isPresent() ? labelMapper.get().getName(metricName) : metricName;
+    return new MetricMetadata(
+        PrometheusNaming.sanitizeMetricName(name), getHelpMessage(metricName, metric));
+  }
+
+  /**
+   * Export counter as Prometheus <a
+   * href="https://prometheus.io/docs/concepts/metric_types/#gauge">Gauge</a>.
+   */
+  MetricSnapshot fromCounter(String dropwizardName, Counter counter) {
+    MetricMetadata metadata = getMetricMetaData(dropwizardName, counter);
+    CounterSnapshot.CounterDataPointSnapshot.Builder dataPointBuilder =
+        CounterSnapshot.CounterDataPointSnapshot.builder()
+            .value(Long.valueOf(counter.getCount()).doubleValue());
+    labelMapper.ifPresent(
+        mapper ->
+            dataPointBuilder.labels(
+                mapper.getLabels(
+                    dropwizardName, Collections.emptyList(), Collections.emptyList())));
+    return new CounterSnapshot(metadata, Collections.singletonList(dataPointBuilder.build()));
+  }
+
+  /** Export gauge as a prometheus gauge. */
+  MetricSnapshot fromGauge(String dropwizardName, Gauge<?> gauge) {
+    Object obj = gauge.getValue();
+    double value;
+    if (obj instanceof Number) {
+      value = ((Number) obj).doubleValue();
+    } else if (obj instanceof Boolean) {
+      value = ((Boolean) obj) ? 1 : 0;
+    } else {
+      logger.log(
+          Level.FINE,
+          String.format(
+              "Invalid type for Gauge %s: %s",
+              PrometheusNaming.sanitizeMetricName(dropwizardName),
+              obj == null ? "null" : obj.getClass().getName()));
+      return null;
+    }
+    MetricMetadata metadata = getMetricMetaData(dropwizardName, gauge);
+    GaugeSnapshot.GaugeDataPointSnapshot.Builder dataPointBuilder =
+        GaugeSnapshot.GaugeDataPointSnapshot.builder().value(value);
+    labelMapper.ifPresent(
+        mapper ->
+            dataPointBuilder.labels(
+                mapper.getLabels(
+                    dropwizardName, Collections.emptyList(), Collections.emptyList())));
+    return new GaugeSnapshot(metadata, Collections.singletonList(dataPointBuilder.build()));
+  }
+
+  /**
+   * Export a histogram snapshot as a prometheus SUMMARY.
+   *
+   * @param dropwizardName metric name.
+   * @param snapshot the histogram snapshot.
+   * @param count the total sample count for this snapshot.
+   * @param factor a factor to apply to histogram values.
+   */
+  MetricSnapshot fromSnapshotAndCount(
+      String dropwizardName, Snapshot snapshot, long count, double factor, String helpMessage) {
+    Quantiles quantiles =
+        Quantiles.builder()
+            .quantile(0.5, snapshot.getMedian() * factor)
+            .quantile(0.75, snapshot.get75thPercentile() * factor)
+            .quantile(0.95, snapshot.get95thPercentile() * factor)
+            .quantile(0.98, snapshot.get98thPercentile() * factor)
+            .quantile(0.99, snapshot.get99thPercentile() * factor)
+            .quantile(0.999, snapshot.get999thPercentile() * factor)
+            .build();
+
+    MetricMetadata metadata =
+        new MetricMetadata(PrometheusNaming.sanitizeMetricName(dropwizardName), helpMessage);
+    SummarySnapshot.SummaryDataPointSnapshot.Builder dataPointBuilder =
+        SummarySnapshot.SummaryDataPointSnapshot.builder().quantiles(quantiles).count(count);
+    labelMapper.ifPresent(
+        mapper ->
+            dataPointBuilder.labels(
+                mapper.getLabels(
+                    dropwizardName, Collections.emptyList(), Collections.emptyList())));
+    return new SummarySnapshot(metadata, Collections.singletonList(dataPointBuilder.build()));
+  }
+
+  /** Convert histogram snapshot. */
+  MetricSnapshot fromHistogram(String dropwizardName, Histogram histogram) {
+    return fromSnapshotAndCount(
+        dropwizardName,
+        histogram.getSnapshot(),
+        histogram.getCount(),
+        1.0,
+        getHelpMessage(dropwizardName, histogram));
+  }
+
+  /** Export Dropwizard Timer as a histogram. Use TIME_UNIT as time unit. */
+  MetricSnapshot fromTimer(String dropwizardName, Timer timer) {
+    return fromSnapshotAndCount(
+        dropwizardName,
+        timer.getSnapshot(),
+        timer.getCount(),
+        1.0D / TimeUnit.SECONDS.toNanos(1L),
+        getHelpMessage(dropwizardName, timer));
+  }
+
+  /** Export a Meter as a prometheus COUNTER. */
+  MetricSnapshot fromMeter(String dropwizardName, Meter meter) {
+    MetricMetadata metadata = getMetricMetaData(dropwizardName + "_total", meter);
+    CounterSnapshot.CounterDataPointSnapshot.Builder dataPointBuilder =
+        CounterSnapshot.CounterDataPointSnapshot.builder().value(meter.getCount());
+    labelMapper.ifPresent(
+        mapper ->
+            dataPointBuilder.labels(
+                mapper.getLabels(
+                    dropwizardName, Collections.emptyList(), Collections.emptyList())));
+    return new CounterSnapshot(metadata, Collections.singletonList(dataPointBuilder.build()));
+  }
+
+  @Override
+  public MetricSnapshots collect() {
+    MetricSnapshots.Builder metricSnapshots = MetricSnapshots.builder();
+
+    registry
+        .getGauges(metricFilter)
+        .forEach(
+            (name, gauge) -> {
+              MetricSnapshot snapshot = fromGauge(name, gauge);
+              if (snapshot != null) {
+                metricSnapshots.metricSnapshot(snapshot);
+              }
+            });
+
+    registry
+        .getCounters(metricFilter)
+        .forEach((name, counter) -> metricSnapshots.metricSnapshot(fromCounter(name, counter)));
+    registry
+        .getHistograms(metricFilter)
+        .forEach(
+            (name, histogram) -> metricSnapshots.metricSnapshot(fromHistogram(name, histogram)));
+    registry
+        .getTimers(metricFilter)
+        .forEach((name, timer) -> metricSnapshots.metricSnapshot(fromTimer(name, timer)));
+    registry
+        .getMeters(metricFilter)
+        .forEach((name, meter) -> metricSnapshots.metricSnapshot(fromMeter(name, meter)));
+
+    return metricSnapshots.build();
+  }
+
+  public static Builder builder() {
+    return new Builder();
+  }
+
+  // Builder class for DropwizardExports
+  public static class Builder {
+    private MetricRegistry registry;
+    private MetricFilter metricFilter;
+    private CustomLabelMapper labelMapper;
+
+    private Builder() {
+      this.metricFilter = MetricFilter.ALL;
+    }
+
+    public Builder dropwizardRegistry(MetricRegistry registry) {
+      this.registry = registry;
+      return this;
+    }
+
+    public Builder metricFilter(MetricFilter metricFilter) {
+      this.metricFilter = metricFilter;
+      return this;
+    }
+
+    public Builder customLabelMapper(CustomLabelMapper labelMapper) {
+      this.labelMapper = labelMapper;
+      return this;
+    }
+
+    DropwizardExports build() {
+      if (registry == null) {
+        throw new IllegalArgumentException("MetricRegistry must be set");
+      }
+      if (labelMapper == null) {
+        return new DropwizardExports(registry, metricFilter);
+      } else {
+        return new DropwizardExports(registry, metricFilter, labelMapper);
+      }
+    }
+
+    public void register() {
+      register(PrometheusRegistry.defaultRegistry);
+    }
+
+    public void register(PrometheusRegistry registry) {
+      DropwizardExports dropwizardExports = build();
+      registry.register(dropwizardExports);
+    }
+  }
+}