Add support for configuring common tags declaratively

Closes gh-12933

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/MetricsProperties.java

@@ -44,6 +44,11 @@ public class MetricsProperties {
 	 */
 	private Map<String, Boolean> enable = new LinkedHashMap<>();
 
+	/**
+	 * Common tags that are applied to every meter.
+	 */
+	private final Map<String, String> tags = new LinkedHashMap<>();
+
 	private final Web web = new Web();
 
 	private final Distribution distribution = new Distribution();
@@ -65,6 +70,10 @@ public class MetricsProperties {
 		this.enable = enable;
 	}
 
+	public Map<String, String> getTags() {
+		return this.tags;
+	}
+
 	public Web getWeb() {
 		return this.web;
 	}

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/PropertiesMeterFilter.java

@@ -19,9 +19,12 @@ package org.springframework.boot.actuate.autoconfigure.metrics;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.Objects;
+import java.util.stream.Collectors;
 
 import io.micrometer.core.instrument.Meter;
 import io.micrometer.core.instrument.Meter.Id;
+import io.micrometer.core.instrument.Tag;
+import io.micrometer.core.instrument.Tags;
 import io.micrometer.core.instrument.config.MeterFilter;
 import io.micrometer.core.instrument.config.MeterFilterReply;
 import io.micrometer.core.instrument.distribution.DistributionStatisticConfig;
@@ -35,17 +38,30 @@ import org.springframework.util.StringUtils;
  *
  * @author Jon Schneider
  * @author Phillip Webb
+ * @author Stephane Nicoll
  * @since 2.0.0
  */
 public class PropertiesMeterFilter implements MeterFilter {
 
 	private static final ServiceLevelAgreementBoundary[] EMPTY_SLA = {};
 
-	private MetricsProperties properties;
+	private final MetricsProperties properties;
+
+	private final MeterFilter mapFilter;
 
 	public PropertiesMeterFilter(MetricsProperties properties) {
 		Assert.notNull(properties, "Properties must not be null");
 		this.properties = properties;
+		this.mapFilter = createMapFilter(properties.getTags());
+	}
+
+	private static MeterFilter createMapFilter(Map<String, String> tags) {
+		if (tags.isEmpty()) {
+			return new MeterFilter() { };
+		}
+		Tags commonTags = Tags.of(tags.entrySet().stream().map((entry) ->
+				Tag.of(entry.getKey(), entry.getValue())).collect(Collectors.toList()));
+		return MeterFilter.commonTags(commonTags);
 	}
 
 	@Override
@@ -54,6 +70,11 @@ public class PropertiesMeterFilter implements MeterFilter {
 		return (enabled ? MeterFilterReply.NEUTRAL : MeterFilterReply.DENY);
 	}
 
+	@Override
+	public Id map(Id id) {
+		return this.mapFilter.map(id);
+	}
+
 	@Override
 	public DistributionStatisticConfig configure(Meter.Id id,
 			DistributionStatisticConfig config) {

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/MetricsAutoConfigurationIntegrationTests.java

@@ -55,6 +55,19 @@ public class MetricsAutoConfigurationIntegrationTests {
 				});
 	}
 
+	@Test
+	public void propertyBasedCommonTagsIsAutoConfigured() {
+		this.contextRunner.withPropertyValues("management.metrics.tags.region=test",
+				"management.metrics.tags.origin=local")
+				.run((context) -> {
+					MeterRegistry registry = context.getBean(MeterRegistry.class);
+					registry.counter("my.counter", "env", "qa");
+					assertThat(registry.find("my.counter").tags("env", "qa")
+							.tags("region", "test").tags("origin", "local").counter())
+							.isNotNull();
+				});
+	}
+
 	@Test
 	public void simpleMeterRegistryIsUsedAsAFallback() {
 		this.contextRunner

spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -1432,6 +1432,7 @@ content into your application. Rather, pick only the properties that you need.
 	management.metrics.export.wavefront.step=10s # Step size (i.e. reporting frequency) to use.
 	management.metrics.export.wavefront.uri=https://longboard.wavefront.com # URI to ship metrics to.
 	management.metrics.use-global-registry=true # Whether auto-configured MeterRegistry implementations should be bound to the global static registry on Metrics.
+	management.metrics.tags.*= # Common tags that are applied to every meter.
 	management.metrics.web.client.max-uri-tags=100 # Maximum number of unique URI tag values allowed. After the max number of tag values is reached, metrics with additional tag values are denied by filter.
 	management.metrics.web.client.requests-metric-name=http.client.requests # Name of the metric for sent requests.
 	management.metrics.web.server.auto-time-requests=true # Whether requests handled by Spring MVC or WebFlux should be automatically timed.

spring-boot-project/spring-boot-docs/src/main/asciidoc/production-ready-features.adoc

@@ -1846,6 +1846,21 @@ all meter IDs beginning with `com.example`, you can do the following:
 include::{code-examples}/actuate/metrics/MetricsFilterBeanExample.java[tag=configuration]
 ----
 
+[[production-ready-metrics-common-tags]]
+==== Common tags
+Common tag are generally used for dimensional drill-down on the operating environment like
+host, instance, region, stack, etc. Commons tags applied to all meters and can be
+configured as shown in the following example:
+
+[source,properties,indent=0]
+----
+	management.metrics.tags.region=us-east-1
+	management.metrics.tags.stack=prod
+----
+
+The example above adds a `region` and `stack` tags to all meters with a value of
+`us-east-1` and `prod` respectively.
+
 
 
 ==== Per-meter properties