#14: support exporting metrics from Prometheus CollectorRegistry, add…

README.md

@@ -1724,6 +1724,31 @@ Dependencies:
 </dependency>
 ```
 
+Note that ```metrics-facade-prometheus``` uses
+```xml
+<dependency>
+    <groupId>io.prometheus</groupId>
+    <artifactId>simpleclient_common</artifactId>
+    <version>...</version>
+</dependency>
+```
+
+In case of conflict between the ```simpleclient_common``` version used in ```Metrics Facade``` and the one used in your project, you can resolve it with ```dependency.exclusions``` or any other available means. For example, see ```metrics-facade-samples/pom.xml```:
+```xml
+<dependency>
+    <groupId>com.ringcentral.platform.metrics</groupId>
+    <artifactId>metrics-facade-prometheus</artifactId>
+    <version>${project.version}</version>
+
+    <exclusions>
+        <exclusion>
+            <groupId>io.prometheus</groupId>
+            <artifactId>simpleclient_common</artifactId>
+        </exclusion>
+    </exclusions>
+</dependency>
+```
+
 Example:
 ```java
 MetricRegistry registry = new DefaultMetricRegistry();

metrics-facade-prometheus/src/main/java/com/ringcentral/platform/metrics/reporters/prometheus/PrometheusMetricsExporter.java

@@ -3,19 +3,27 @@
 import com.ringcentral.platform.metrics.MetricRegistry;
 import com.ringcentral.platform.metrics.names.MetricName;
 import com.ringcentral.platform.metrics.reporters.MetricsExporter;
-import com.ringcentral.platform.metrics.samples.*;
-import com.ringcentral.platform.metrics.samples.prometheus.*;
+import com.ringcentral.platform.metrics.samples.CompositeInstanceSamplesProvider;
+import com.ringcentral.platform.metrics.samples.InstanceSamplesProvider;
+import com.ringcentral.platform.metrics.samples.prometheus.PrometheusInstanceSample;
+import com.ringcentral.platform.metrics.samples.prometheus.PrometheusInstanceSamplesProvider;
+import com.ringcentral.platform.metrics.samples.prometheus.PrometheusSample;
+import com.ringcentral.platform.metrics.samples.prometheus.collectorRegistry.SimpleCollectorRegistryPrometheusInstanceSamplesProvider;
 import com.ringcentral.platform.metrics.utils.StringBuilderWriter;
+import io.prometheus.client.CollectorRegistry;
 import io.prometheus.client.exporter.common.TextFormat;
 import org.slf4j.Logger;
 
-import java.io.*;
+import java.io.IOException;
+import java.io.Writer;
 import java.util.*;
 
 import static com.ringcentral.platform.metrics.reporters.prometheus.PrometheusMetricsExporter.Format.PROMETHEUS_TEXT_O_O_4;
-import static io.prometheus.client.Collector.*;
-import static java.lang.String.*;
-import static java.util.Collections.*;
+import static io.prometheus.client.Collector.MetricFamilySamples;
+import static io.prometheus.client.Collector.sanitizeMetricName;
+import static java.lang.String.join;
+import static java.util.Collections.emptyList;
+import static java.util.Collections.enumeration;
 import static java.util.stream.Collectors.toList;
 import static org.slf4j.LoggerFactory.getLogger;
 
@@ -48,6 +56,12 @@ public PrometheusMetricsExporter(MetricRegistry registry) {
         this(new PrometheusInstanceSamplesProvider(registry));
     }
 
+    public PrometheusMetricsExporter(MetricRegistry registry, CollectorRegistry... collectorRegistries) {
+        this(
+            new PrometheusInstanceSamplesProvider(registry),
+            new SimpleCollectorRegistryPrometheusInstanceSamplesProvider(collectorRegistries));
+    }
+
     public PrometheusMetricsExporter(
         MetricRegistry registry,
         boolean convertNameToLowercase,
@@ -200,10 +214,7 @@ private void exportInstanceSample(PrometheusInstanceSample is, Map<MetricName, M
     }
 
     private MetricFamilySamples toMetricFamilySamples(PrometheusInstanceSample is) {
-        String name =
-            convertNameToLowercase ?
-            sanitizeMetricName(join(NAME_PARTS_DELIMITER, is.name())).toLowerCase(locale) :
-            sanitizeMetricName(join(NAME_PARTS_DELIMITER, is.name()));
+        String name = buildName(is.name());
 
         return new MetricFamilySamples(
             name,
@@ -213,11 +224,10 @@ private MetricFamilySamples toMetricFamilySamples(PrometheusInstanceSample is) {
                 .map(s -> {
                     String sampleName = name;
 
-                    if (s.hasNameSuffix()) {
-                        sampleName +=
-                            convertNameToLowercase ?
-                            sanitizeMetricName(s.nameSuffix()).toLowerCase(locale) :
-                            sanitizeMetricName(s.nameSuffix());
+                    if (s.hasName()) {
+                        sampleName = buildName(s.name());
+                    } else if (s.hasNameSuffix()) {
+                        sampleName += buildNameSuffix(s);
                     }
 
                     return new MetricFamilySamples.Sample(
@@ -229,6 +239,17 @@ private MetricFamilySamples toMetricFamilySamples(PrometheusInstanceSample is) {
                 .collect(toList()));
     }
 
+    private String buildName(MetricName name) {
+        final var sanitizedName = sanitizeMetricName(join(NAME_PARTS_DELIMITER, name));
+        return convertNameToLowercase ? sanitizedName.toLowerCase(locale) : sanitizedName;
+    }
+
+    private String buildNameSuffix(PrometheusSample ps) {
+        final var suffix = ps.nameSuffix();
+        final var sanitizedSuffix = sanitizeMetricName(suffix);
+        return convertNameToLowercase ? sanitizedSuffix.toLowerCase(locale) : sanitizedSuffix;
+    }
+
     private static String helpFor(PrometheusInstanceSample is) {
         return
             is.hasDescription() ?

metrics-facade-prometheus/src/main/java/com/ringcentral/platform/metrics/samples/prometheus/PrometheusInstanceSamplesProviderBuilder.java

@@ -0,0 +1,74 @@
+package com.ringcentral.platform.metrics.samples.prometheus;
+
+import com.ringcentral.platform.metrics.MetricRegistry;
+import com.ringcentral.platform.metrics.infoProviders.PredicativeMetricNamedInfoProvider;
+import com.ringcentral.platform.metrics.samples.InstanceSampleMaker;
+import com.ringcentral.platform.metrics.samples.InstanceSampleSpecProvider;
+import com.ringcentral.platform.metrics.samples.SampleMaker;
+import com.ringcentral.platform.metrics.samples.SampleSpecProvider;
+
+import static java.util.Objects.requireNonNull;
+
+public class PrometheusInstanceSamplesProviderBuilder {
+
+    private InstanceSampleSpecProvider<PrometheusInstanceSampleSpec> instanceSampleSpecProvider;
+    private PredicativeMetricNamedInfoProvider<InstanceSampleSpecProvider<PrometheusInstanceSampleSpec>> instanceSampleSpecModsProvider;
+    private InstanceSampleMaker<PrometheusSample, PrometheusInstanceSample, PrometheusInstanceSampleSpec> instanceSampleMaker;
+    private SampleSpecProvider<PrometheusSampleSpec, PrometheusInstanceSampleSpec> sampleSpecProvider;
+    private PredicativeMetricNamedInfoProvider<SampleSpecProvider<PrometheusSampleSpec, PrometheusInstanceSampleSpec>> sampleSpecModsProvider;
+    private SampleMaker<PrometheusSample, PrometheusSampleSpec, PrometheusInstanceSampleSpec> sampleMaker;
+    private final MetricRegistry metricRegistry;
+
+    public PrometheusInstanceSamplesProviderBuilder(MetricRegistry metricRegistry) {
+        this.metricRegistry = requireNonNull(metricRegistry);
+        this.instanceSampleSpecProvider = new PrometheusInstanceSampleSpecProvider();
+        this.instanceSampleMaker = new PrometheusInstanceSampleMaker();
+        this.sampleSpecProvider = new PrometheusSampleSpecProvider();
+        this.sampleMaker = new PrometheusSampleMaker();
+    }
+
+    public static PrometheusInstanceSamplesProviderBuilder prometheusInstanceSamplesProvider(MetricRegistry metricRegistry) {
+        return new PrometheusInstanceSamplesProviderBuilder(metricRegistry);
+    }
+
+    public PrometheusInstanceSamplesProviderBuilder instanceSampleSpecProvider(InstanceSampleSpecProvider<PrometheusInstanceSampleSpec> instanceSampleSpecProvider) {
+        this.instanceSampleSpecProvider = requireNonNull(instanceSampleSpecProvider);
+        return this;
+    }
+
+    public PrometheusInstanceSamplesProviderBuilder instanceSampleSpecModsProvider(PredicativeMetricNamedInfoProvider<InstanceSampleSpecProvider<PrometheusInstanceSampleSpec>> instanceSampleSpecModsProvider) {
+        this.instanceSampleSpecModsProvider = instanceSampleSpecModsProvider;
+        return this;
+    }
+
+    public PrometheusInstanceSamplesProviderBuilder instanceSampleMaker(InstanceSampleMaker<PrometheusSample, PrometheusInstanceSample, PrometheusInstanceSampleSpec> instanceSampleMaker) {
+        this.instanceSampleMaker = requireNonNull(instanceSampleMaker);
+        return this;
+    }
+
+    public PrometheusInstanceSamplesProviderBuilder sampleSpecProvider(SampleSpecProvider<PrometheusSampleSpec, PrometheusInstanceSampleSpec> sampleSpecProvider) {
+        this.sampleSpecProvider = requireNonNull(sampleSpecProvider);
+        return this;
+    }
+
+    public PrometheusInstanceSamplesProviderBuilder sampleSpecModsProvider(PredicativeMetricNamedInfoProvider<SampleSpecProvider<PrometheusSampleSpec, PrometheusInstanceSampleSpec>> sampleSpecModsProvider) {
+        this.sampleSpecModsProvider = sampleSpecModsProvider;
+        return this;
+    }
+
+    public PrometheusInstanceSamplesProviderBuilder sampleMaker(SampleMaker<PrometheusSample, PrometheusSampleSpec, PrometheusInstanceSampleSpec> sampleMaker) {
+        this.sampleMaker = requireNonNull(sampleMaker);
+        return this;
+    }
+
+    public PrometheusInstanceSamplesProvider build() {
+        return new PrometheusInstanceSamplesProvider(
+            instanceSampleSpecProvider,
+            instanceSampleSpecModsProvider,
+            instanceSampleMaker,
+            sampleSpecProvider,
+            sampleSpecModsProvider,
+            sampleMaker,
+            metricRegistry);
+    }
+}

metrics-facade-prometheus/src/main/java/com/ringcentral/platform/metrics/samples/prometheus/PrometheusSample.java

@@ -13,7 +13,7 @@ public class PrometheusSample implements Sample {
 
     private final MetricName childInstanceSampleNameSuffix;
     private final Collector.Type childInstanceSampleType;
-
+    private final MetricName name;
     private final String nameSuffix;
     private final List<String> labelNames;
     private final List<String> labelValues;
@@ -22,6 +22,7 @@ public class PrometheusSample implements Sample {
     public PrometheusSample(
         MetricName childInstanceSampleNameSuffix,
         Collector.Type childInstanceSampleType,
+        MetricName name,
         String nameSuffix,
         List<String> labelNames,
         List<String> labelValues,
@@ -35,6 +36,7 @@ public PrometheusSample(
         this.childInstanceSampleNameSuffix = childInstanceSampleNameSuffix;
         this.childInstanceSampleType = childInstanceSampleType;
 
+        this.name = name;
         this.nameSuffix = nameSuffix;
         this.labelNames = labelNames != null ? labelNames : emptyList();
         this.labelValues = labelValues != null ? labelValues : emptyList();
@@ -57,12 +59,21 @@ public PrometheusSample notBelongingToChildInstanceSample() {
         return new PrometheusSample(
             null,
             null,
+            name,
             nameSuffix,
             labelNames,
             labelValues,
             value);
     }
 
+    public boolean hasName() {
+        return name != null;
+    }
+
+    public MetricName name() {
+        return name;
+    }
+
     public boolean hasNameSuffix() {
         return nameSuffix != null;
     }

metrics-facade-prometheus/src/main/java/com/ringcentral/platform/metrics/samples/prometheus/PrometheusSampleMaker.java

@@ -93,6 +93,7 @@ public PrometheusSample makeSample(PrometheusSampleSpec spec, PrometheusInstance
         return new PrometheusSample(
             childInstanceSampleNameSuffix,
             childInstanceSampleType,
+            null,
             nameSuffix,
             labelNames,
             labelValues,