Fixes #554. Apply Metric Filter on all external metrics

src/main/java/org/jenkinsci/plugins/prometheus/config/disabledmetrics/MetricStatusChecker.java

@@ -1,12 +1,15 @@
 package org.jenkinsci.plugins.prometheus.config.disabledmetrics;
 
+import io.prometheus.client.Collector;
+import io.prometheus.client.CollectorRegistry;
 import org.jenkinsci.plugins.prometheus.config.PrometheusConfiguration;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.List;
+import java.util.*;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 
 public class MetricStatusChecker {
 
@@ -51,4 +54,11 @@ public static boolean isEnabled(String metricName) {
         }
         return true;
     }
+
+    public static Set<String> filter(List<String> allMetricNames) {
+        if (allMetricNames == null) {
+            return new HashSet<>();
+        }
+        return allMetricNames.stream().filter(MetricStatusChecker::isEnabled).collect(Collectors.toSet());
+    }
 }

src/main/java/org/jenkinsci/plugins/prometheus/service/DefaultPrometheusMetrics.java

@@ -8,12 +8,14 @@
 import io.prometheus.client.hotspot.DefaultExports;
 import jenkins.metrics.api.Metrics;
 import org.jenkinsci.plugins.prometheus.*;
+import org.jenkinsci.plugins.prometheus.config.disabledmetrics.MetricStatusChecker;
 import org.jenkinsci.plugins.prometheus.util.JenkinsNodeBuildsSampleBuilder;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 import java.io.StringWriter;
+import java.util.*;
 import java.util.concurrent.atomic.AtomicReference;
 
 public class DefaultPrometheusMetrics implements PrometheusMetrics {
@@ -49,10 +51,23 @@ public String getMetrics() {
     @Override
     public void collectMetrics() {
         try (StringWriter buffer = new StringWriter()) {
-            TextFormat.write004(buffer, collectorRegistry.metricFamilySamples());
+            Set<String> filteredMetrics = MetricStatusChecker.filter(getMetricNames());
+            TextFormat.write004(buffer, collectorRegistry.filteredMetricFamilySamples(filteredMetrics));
             cachedMetrics.set(buffer.toString());
         } catch (IOException e) {
             logger.debug("Unable to collect metrics");
         }
     }
+
+    private List<String> getMetricNames() {
+        Enumeration<Collector.MetricFamilySamples> metricFamilySamplesEnumeration = collectorRegistry.metricFamilySamples();
+        List<String> allMetricNames = new ArrayList<>();
+        while (metricFamilySamplesEnumeration.hasMoreElements()) {
+            Collector.MetricFamilySamples familySamples = metricFamilySamplesEnumeration.nextElement();
+            if (familySamples != null && familySamples.name != null) {
+                allMetricNames.add(familySamples.name);
+            }
+        }
+        return allMetricNames;
+    }
 }

src/test/java/org/jenkinsci/plugins/prometheus/config/disabledmetrics/MetricStatusCheckerTest.java

@@ -9,6 +9,7 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
 
 import static org.mockito.Mockito.*;
 
@@ -181,6 +182,32 @@ void testNamedDisabledMetricAndRegexAvailableMatches() {
         }
     }
 
+
+    @Test
+    void testFilterExternalMetricNames() {
+        Jenkins jenkins = mock(Jenkins.class);
+
+        PrometheusConfiguration mockedConfig = mock(PrometheusConfiguration.class);
+        List<Entry> entries = new ArrayList<>();
+        entries.add(new NamedDisabledMetric("other_metric"));
+        entries.add(new RegexDisabledMetric("j?vm.*"));
+        DisabledMetricConfig disabledMetricConfig = new DisabledMetricConfig(entries);
+
+        when(mockedConfig.getDisabledMetricConfig()).thenReturn(disabledMetricConfig);
+
+
+        try (MockedStatic<Jenkins> jenkinsStatic = mockStatic(Jenkins.class);
+             MockedStatic<PrometheusConfiguration> configStatic = mockStatic(PrometheusConfiguration.class)) {
+            jenkinsStatic.when(Jenkins::get).thenReturn(jenkins);
+            configStatic.when(PrometheusConfiguration::get).thenReturn(mockedConfig);
+
+            List<String> allMetrics = List.of("some_metric", "jvm_xxx", "vm_xxx");
+            Set<String> filteredMetrics = MetricStatusChecker.filter(allMetrics);
+            Assertions.assertEquals(1, filteredMetrics.size());
+            Assertions.assertEquals("some_metric", filteredMetrics.stream().findFirst().get());
+        }
+    }
+
     @Test
     // shouldn't take more than 3 seconds
     @Timeout(value = 3L)