[14.x] ISPN-14341 Allow injecting a MeterRegistry instance

core/src/main/java/org/infinispan/metrics/config/MicrometerMeterRegisterConfigurationBuilder.java

@@ -0,0 +1,70 @@
+package org.infinispan.metrics.config;
+
+import java.util.Objects;
+
+import org.infinispan.commons.configuration.Builder;
+import org.infinispan.configuration.global.GlobalConfigurationBuilder;
+
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.prometheus.PrometheusMeterRegistry;
+
+/**
+ * Builder to inject an instance of {@link MeterRegistry}.
+ * <p>
+ * If not configured, Infinispan will create a new instance of {@link PrometheusMeterRegistry}.
+ *
+ * @since 15.0
+ */
+public class MicrometerMeterRegisterConfigurationBuilder implements Builder<MicrometerMeterRegistryConfiguration> {
+
+   private MeterRegistry meterRegistry;
+
+   public MicrometerMeterRegisterConfigurationBuilder(GlobalConfigurationBuilder builder) {
+      //required because GlobalConfigurationBuilder#addModule uses reflection
+   }
+
+   /**
+    * Set the {@link MeterRegistry} instance to use by Infinispan.
+    * <p>
+    * If set to {@code null}, Infinispan will create a new instance of {@link PrometheusMeterRegistry}.
+    *
+    * @param registry The {@link MeterRegistry} to use or {@code null}.
+    */
+   public MicrometerMeterRegisterConfigurationBuilder meterRegistry(MeterRegistry registry) {
+      meterRegistry = registry;
+      return this;
+   }
+
+   @Override
+   public MicrometerMeterRegistryConfiguration create() {
+      return new MicrometerMeterRegistryConfiguration(meterRegistry);
+   }
+
+   @Override
+   public MicrometerMeterRegisterConfigurationBuilder read(MicrometerMeterRegistryConfiguration template) {
+      meterRegistry(template.meterRegistry());
+      return this;
+   }
+
+   @Override
+   public boolean equals(Object o) {
+      if (this == o) return true;
+      if (!(o instanceof MicrometerMeterRegisterConfigurationBuilder)) return false;
+
+      MicrometerMeterRegisterConfigurationBuilder that = (MicrometerMeterRegisterConfigurationBuilder) o;
+
+      return Objects.equals(meterRegistry, that.meterRegistry);
+   }
+
+   @Override
+   public int hashCode() {
+      return meterRegistry != null ? meterRegistry.hashCode() : 0;
+   }
+
+   @Override
+   public String toString() {
+      return "MicrometerMeterRegisterConfigurationBuilder{" +
+            "meterRegistry=" + meterRegistry +
+            '}';
+   }
+}

core/src/main/java/org/infinispan/metrics/config/MicrometerMeterRegistryConfiguration.java

@@ -0,0 +1,51 @@
+package org.infinispan.metrics.config;
+
+import java.util.Objects;
+
+import org.infinispan.configuration.serializing.SerializedWith;
+
+import io.micrometer.core.instrument.MeterRegistry;
+
+/**
+ * A configuration class to inject a custom {@link MeterRegistry} instance.
+ *
+ * @since 15.0
+ */
+@SerializedWith(MicrometerMeterRegistryConfigurationSerializer.class)
+public class MicrometerMeterRegistryConfiguration {
+
+   private final MeterRegistry registry;
+
+   public MicrometerMeterRegistryConfiguration(MeterRegistry registry) {
+      this.registry = registry;
+   }
+
+   /**
+    * @return The {@link MeterRegistry} instance injected or {@code null} if not configured.
+    */
+   public MeterRegistry meterRegistry() {
+      return registry;
+   }
+
+   @Override
+   public boolean equals(Object o) {
+      if (this == o) return true;
+      if (!(o instanceof MicrometerMeterRegistryConfiguration)) return false;
+
+      MicrometerMeterRegistryConfiguration that = (MicrometerMeterRegistryConfiguration) o;
+
+      return Objects.equals(registry, that.registry);
+   }
+
+   @Override
+   public int hashCode() {
+      return registry != null ? registry.hashCode() : 0;
+   }
+
+   @Override
+   public String toString() {
+      return "MicrometerMeterRegistryConfiguration{" +
+            "registry=" + registry +
+            '}';
+   }
+}

core/src/main/java/org/infinispan/metrics/config/MicrometerMeterRegistryConfigurationSerializer.java

@@ -0,0 +1,18 @@
+package org.infinispan.metrics.config;
+
+import org.infinispan.commons.configuration.io.ConfigurationWriter;
+import org.infinispan.configuration.serializing.ConfigurationSerializer;
+
+/**
+ * A {@link ConfigurationSerializer} implementation to serialize {@link MicrometerMeterRegistryConfiguration}.
+ * <p>
+ * This class is a no-op.
+ *
+ * @since 15.0
+ */
+public class MicrometerMeterRegistryConfigurationSerializer implements ConfigurationSerializer<MicrometerMeterRegistryConfiguration> {
+   @Override
+   public void serialize(ConfigurationWriter writer, MicrometerMeterRegistryConfiguration configuration) {
+      //no-op
+   }
+}

core/src/main/java/org/infinispan/metrics/impl/MetricsCollector.java

@@ -24,12 +24,14 @@
 import org.infinispan.factories.scopes.Scope;
 import org.infinispan.factories.scopes.Scopes;
 import org.infinispan.metrics.Constants;
+import org.infinispan.metrics.config.MicrometerMeterRegistryConfiguration;
 import org.infinispan.remoting.transport.Transport;
 import org.infinispan.util.logging.Log;
 import org.infinispan.util.logging.LogFactory;
 
 import io.micrometer.core.instrument.Gauge;
 import io.micrometer.core.instrument.Meter;
+import io.micrometer.core.instrument.MeterRegistry;
 import io.micrometer.core.instrument.Tag;
 import io.micrometer.core.instrument.Timer;
 import io.micrometer.prometheus.PrometheusConfig;
@@ -48,7 +50,7 @@ public class MetricsCollector implements Constants {
 
    private static final Log log = LogFactory.getLog(MetricsCollector.class);
 
-   private PrometheusMeterRegistry registry;
+   private MeterRegistry registry;
 
    private Tag nodeTag;
 
@@ -64,12 +66,12 @@ protected MetricsCollector() {
    }
 
    public PrometheusMeterRegistry registry() {
-      return registry;
+      return registry instanceof PrometheusMeterRegistry ? (PrometheusMeterRegistry) registry : null;
    }
 
    @Start
    protected void start() {
-      registry = new PrometheusMeterRegistry(PrometheusConfig.DEFAULT);
+      createMeterRegistry();
       new BaseAdditionalMetrics().bindTo(registry);
       new VendorAdditionalMetrics().bindTo(registry);
 
@@ -122,7 +124,6 @@ private static String generateRandomName() {
       return hostName + '-' + rand;
    }
 
-   @SuppressWarnings("unchecked")
    public Set<Object> registerMetrics(Object instance, Collection<MBeanMetadata.AttributeMetadata> attributes, String namePrefix, String cacheName) {
       return registerMetrics(instance, attributes, namePrefix, asTag(CACHE_TAG_NAME, cacheName), nodeTag);
    }
@@ -215,4 +216,12 @@ public void unregisterMetric(Object metricId) {
          }
       }
    }
+
+   private void createMeterRegistry() {
+      MicrometerMeterRegistryConfiguration configuration = globalConfig.module(MicrometerMeterRegistryConfiguration.class);
+      registry = configuration == null ? null : configuration.meterRegistry();
+      if (registry == null) {
+         registry = new PrometheusMeterRegistry(PrometheusConfig.DEFAULT);
+      }
+   }
 }

server/rest/src/main/java/org/infinispan/rest/resources/MetricsResource.java

@@ -1,6 +1,7 @@
 package org.infinispan.rest.resources;
 
 import static io.netty.handler.codec.http.HttpResponseStatus.INTERNAL_SERVER_ERROR;
+import static io.netty.handler.codec.http.HttpResponseStatus.NOT_FOUND;
 import static org.infinispan.rest.framework.Method.GET;
 import static org.infinispan.rest.framework.Method.OPTIONS;
 
@@ -17,6 +18,7 @@
 import org.infinispan.rest.framework.impl.Invocations;
 import org.infinispan.rest.framework.impl.RestResponseBuilder;
 
+import io.micrometer.prometheus.PrometheusMeterRegistry;
 import io.prometheus.client.exporter.common.TextFormat;
 
 /**
@@ -52,9 +54,13 @@ private CompletionStage<RestResponse> metrics(RestRequest restRequest) {
          RestResponseBuilder<NettyRestResponse.Builder> builder = new NettyRestResponse.Builder();
 
          try {
+            PrometheusMeterRegistry registry = metricsCollector.registry();
+            if (registry == null) {
+               return builder.status(NOT_FOUND.code()).build();
+            }
             String contentType = TextFormat.chooseContentType(restRequest.getAcceptHeader());
             builder.header("Content-Type", contentType);
-            builder.entity(metricsCollector.registry().scrape(contentType));
+            builder.entity(registry.scrape(contentType));
 
             return builder.build();
          } catch (Exception e) {