Add common tags via configuration

micrometer-core/src/main/java/io/micronaut/configuration/metrics/common/tags/CommonTagsCondition.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2017-2026 original authors
+ *
+ * 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
+ *
+ * https://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 io.micronaut.configuration.metrics.common.tags;
+
+import io.micronaut.context.condition.Condition;
+import io.micronaut.context.condition.ConditionContext;
+
+import static io.micronaut.configuration.metrics.micrometer.MeterRegistryFactory.MICRONAUT_METRICS_COMMON_TAGS;
+import static io.micronaut.configuration.metrics.micrometer.MeterRegistryFactory.MICRONAUT_METRICS_TAGS;
+
+/**
+ * Activates common tag configuration when either supported property prefix is configured.
+ */
+public final class CommonTagsCondition implements Condition {
+
+    @Override
+    public boolean matches(ConditionContext context) {
+        return containsConfiguredTags(context, MICRONAUT_METRICS_TAGS)
+            || containsConfiguredTags(context, MICRONAUT_METRICS_COMMON_TAGS);
+    }
+
+    private static boolean containsConfiguredTags(ConditionContext<?> context, String property) {
+        return context.containsProperty(property) || context.containsProperties(property);
+    }
+}

micrometer-core/src/main/java/io/micronaut/configuration/metrics/common/tags/CommonTagsConfigurer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2019 original authors
+ * Copyright 2017-2026 original authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,30 +19,41 @@
 import io.micrometer.core.instrument.Tag;
 import io.micronaut.configuration.metrics.aggregator.MeterRegistryConfigurer;
 import io.micronaut.configuration.metrics.annotation.RequiresMetrics;
-import io.micronaut.configuration.metrics.micrometer.ExportConfigurationProperties;
 import io.micronaut.context.annotation.Factory;
 import io.micronaut.context.annotation.Requires;
+import io.micronaut.context.env.Environment;
+import io.micronaut.core.naming.conventions.StringConvention;
+import io.micronaut.core.type.Argument;
 
 import java.util.ArrayList;
+import java.util.LinkedHashMap;
 import java.util.List;
-import java.util.Properties;
+import java.util.Map;
+import java.util.TreeMap;
 
 import static io.micronaut.configuration.metrics.micrometer.MeterRegistryFactory.MICRONAUT_METRICS_COMMON_TAGS;
+import static io.micronaut.configuration.metrics.micrometer.MeterRegistryFactory.MICRONAUT_METRICS_TAGS;
 
 /**
  * Configures every MeterRegistry with common tags.
  */
 @Factory
 @RequiresMetrics
-@Requires(property = MICRONAUT_METRICS_COMMON_TAGS)
+@Requires(condition = CommonTagsCondition.class)
 public class CommonTagsConfigurer implements MeterRegistryConfigurer<MeterRegistry> {
 
+    private static final Argument<Map<String, Object>> STRING_OBJECT_MAP = Argument.mapOf(String.class, Object.class);
+
     private final List<Tag> commonTags = new ArrayList<>();
 
-    public CommonTagsConfigurer(ExportConfigurationProperties configuration) {
-        Properties tags = configuration.getTags();
-        for (String key : tags.stringPropertyNames()) {
-            commonTags.add(Tag.of(key, tags.getProperty(key)));
+    public CommonTagsConfigurer(Environment environment) {
+        Map<String, Object> tags = new TreeMap<>(readConfiguredTags(environment, MICRONAUT_METRICS_TAGS));
+        tags.putAll(readConfiguredTags(environment, MICRONAUT_METRICS_COMMON_TAGS));
+        for (Map.Entry<String, Object> entry : tags.entrySet()) {
+            Object value = entry.getValue();
+            if (value != null) {
+                commonTags.add(Tag.of(entry.getKey(), String.valueOf(value)));
+            }
         }
     }
 
@@ -60,4 +71,14 @@ public Class<MeterRegistry> getType() {
     public int getOrder() {
         return HIGHEST_PRECEDENCE;
     }
+
+    private static Map<String, Object> readConfiguredTags(Environment environment, String property) {
+        if (environment.containsProperties(property)) {
+            return new LinkedHashMap<>(environment.getProperties(property, StringConvention.RAW));
+        }
+        if (environment.containsProperty(property)) {
+            return new LinkedHashMap<>(environment.getProperty(property, STRING_OBJECT_MAP).orElse(Map.of()));
+        }
+        return new LinkedHashMap<>();
+    }
 }

micrometer-core/src/main/java/io/micronaut/configuration/metrics/micrometer/MeterRegistryFactory.java

@@ -45,7 +45,8 @@ public class MeterRegistryFactory {
 
     public static final String MICRONAUT_METRICS = "micronaut.metrics.";
     public static final String MICRONAUT_METRICS_BINDERS = MICRONAUT_METRICS + "binders";
-    public static final String MICRONAUT_METRICS_COMMON_TAGS = MICRONAUT_METRICS + "tags";
+    public static final String MICRONAUT_METRICS_TAGS = MICRONAUT_METRICS + "tags";
+    public static final String MICRONAUT_METRICS_COMMON_TAGS = MICRONAUT_METRICS + "common-tags";
     public static final String MICRONAUT_METRICS_ENABLED = MICRONAUT_METRICS + "enabled";
     public static final String MICRONAUT_METRICS_EXPORT = MICRONAUT_METRICS + "export";
 

micrometer-core/src/test/groovy/io/micronaut/configuration/metrics/common/tags/CommonTagsConfigurerSpec.groovy

@@ -0,0 +1,59 @@
+package io.micronaut.configuration.metrics.common.tags
+
+import io.micrometer.core.instrument.simple.SimpleMeterRegistry
+import io.micronaut.context.ApplicationContext
+import io.micronaut.context.env.Environment
+import io.micronaut.core.naming.conventions.StringConvention
+import spock.lang.Specification
+
+import static io.micronaut.configuration.metrics.micrometer.MeterRegistryFactory.MICRONAUT_METRICS_COMMON_TAGS
+import static io.micronaut.configuration.metrics.micrometer.MeterRegistryFactory.MICRONAUT_METRICS_TAGS
+
+class CommonTagsConfigurerSpec extends Specification {
+
+    void "common-tags override legacy tags for duplicate keys"() {
+        given:
+        ApplicationContext context = ApplicationContext.run([
+                "micronaut.metrics.tags.application"       : "legacy",
+                "micronaut.metrics.tags.region"            : "us-east-1",
+                "micronaut.metrics.common-tags.application": "common-tags",
+                "micronaut.metrics.common-tags.cluster"    : "primary"
+        ])
+        SimpleMeterRegistry registry = new SimpleMeterRegistry()
+
+        when:
+        context.getBean(CommonTagsConfigurer).configure(registry)
+        def counter = registry.counter("test.counter")
+
+        then:
+        counter.id.getTag("application") == "common-tags"
+        counter.id.getTag("region") == "us-east-1"
+        counter.id.getTag("cluster") == "primary"
+
+        cleanup:
+        registry.close()
+        context.close()
+    }
+
+    void "null common tag values are ignored"() {
+        given:
+        Environment environment = Stub() {
+            containsProperties(MICRONAUT_METRICS_TAGS) >> false
+            containsProperty(MICRONAUT_METRICS_TAGS) >> false
+            containsProperties(MICRONAUT_METRICS_COMMON_TAGS) >> true
+            getProperties(MICRONAUT_METRICS_COMMON_TAGS, StringConvention.RAW) >> [application: null, region: "us-east-1"]
+        }
+        SimpleMeterRegistry registry = new SimpleMeterRegistry()
+
+        when:
+        new CommonTagsConfigurer(environment).configure(registry)
+        def counter = registry.counter("test.counter")
+
+        then:
+        counter.id.getTag("application") == null
+        counter.id.getTag("region") == "us-east-1"
+
+        cleanup:
+        registry.close()
+    }
+}

micrometer-core/src/test/groovy/io/micronaut/configuration/metrics/management/endpoint/MetricsEndpointSpec.groovy

@@ -378,12 +378,15 @@ class MetricsEndpointSpec extends Specification {
     }
 
     @Unroll
-    void "test metrics endpoint with common tags"() {
+    void "test metrics endpoint #name with common tags from #configurationStyle #propertyName"() {
         given:
-        run('endpoints.metrics.sensitive'          : false,
-            (MICRONAUT_METRICS_ENABLED)            : true,
-            "micronaut.metrics.binders.web.enabled": true,
-            "micronaut.metrics.tags"               : ["test1": "test1-val", "test2": "test2-val"])
+        Map<String, Object> config = [
+                'endpoints.metrics.sensitive'          : false,
+                (MICRONAUT_METRICS_ENABLED)            : true,
+                "micronaut.metrics.binders.web.enabled": true
+        ]
+        config.putAll(tagsConfig)
+        run(config)
 
         expect:
         100.times {
@@ -400,7 +403,15 @@ class MetricsEndpointSpec extends Specification {
         }
 
         where:
-        name << ["process.files.open", "process.files.max"]
+        configurationStyle | propertyName                    | name                | tagsConfig
+        "dotted"           | "micronaut.metrics.tags"        | "process.files.open" | ["micronaut.metrics.tags.test1"       : "test1-val", "micronaut.metrics.tags.test2"       : "test2-val"]
+        "dotted"           | "micronaut.metrics.tags"        | "process.files.max"  | ["micronaut.metrics.tags.test1"       : "test1-val", "micronaut.metrics.tags.test2"       : "test2-val"]
+        "dotted"           | "micronaut.metrics.common-tags" | "process.files.open" | ["micronaut.metrics.common-tags.test1": "test1-val", "micronaut.metrics.common-tags.test2": "test2-val"]
+        "dotted"           | "micronaut.metrics.common-tags" | "process.files.max"  | ["micronaut.metrics.common-tags.test1": "test1-val", "micronaut.metrics.common-tags.test2": "test2-val"]
+        "map"              | "micronaut.metrics.tags"        | "process.files.open" | ["micronaut.metrics.tags"             : [test1: "test1-val", test2: "test2-val"]]
+        "map"              | "micronaut.metrics.tags"        | "process.files.max"  | ["micronaut.metrics.tags"             : [test1: "test1-val", test2: "test2-val"]]
+        "map"              | "micronaut.metrics.common-tags" | "process.files.open" | ["micronaut.metrics.common-tags"      : [test1: "test1-val", test2: "test2-val"]]
+        "map"              | "micronaut.metrics.common-tags" | "process.files.max"  | ["micronaut.metrics.common-tags"      : [test1: "test1-val", test2: "test2-val"]]
     }
 
     @Unroll

micrometer-core/src/test/groovy/io/micronaut/configuration/metrics/micrometer/MeterRegistryConfigurerOrderSpec.groovy

@@ -11,14 +11,13 @@ class MeterRegistryConfigurerOrderSpec extends Specification {
     void "verify beans created by in correct order"() {
         when:
         ApplicationContext ctx = ApplicationContext.run([
-                "test.properties.enabled": true,
-                "micronaut.metrics.tags.test": "test"
+                "test.properties.enabled": true
         ])
 
         List<MeterRegistryConfigurer> configurerList = ctx.getBeansOfType(MeterRegistryConfigurer)
 
         then:
-        configurerList.size() == 3
+        configurerList.any { it.getClass() == CompositeMeterRegistryConfigurer.class }
         configurerList.last().getClass() == CompositeMeterRegistryConfigurer.class
 
         cleanup:

src/main/docs/guide/metricsConcepts.adoc

@@ -26,6 +26,18 @@ include::{metricscore}/aggregator/MeterRegistryConfigurer.java[]
 include::{testsmetricscore}/SimpleMeterRegistryConfigurer.java[]
 ----
 
+Micronaut can also add common tags to every meter via configuration. The legacy `micronaut.metrics.tags.*` prefix remains supported, and `micronaut.metrics.common-tags.*` is available as a clearer alias.
+When both prefixes configure the same tag key, `micronaut.metrics.common-tags.*` takes precedence.
+
+[configuration]
+----
+micronaut:
+  metrics:
+    common-tags:
+      application: ${micronaut.application.name}
+      region: us-east-1
+----
+
 === Meter Filter
 
 * A https://micrometer.io/docs/concepts#_meter_filters[meter filter] can be used to determine if a Meter is to be added to the registry.