Apply micrometer MeterFilter beans automatically

Update `MeterRegistryPostProcessor` and `MetricsAutoConfiguration` so
that micrometer `MeterFilter` beans are automatically applied.

Fixes gh-11843

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

@@ -23,17 +23,17 @@ import io.micrometer.core.instrument.MeterRegistry;
 import io.micrometer.core.instrument.Metrics;
 import io.micrometer.core.instrument.binder.MeterBinder;
 import io.micrometer.core.instrument.composite.CompositeMeterRegistry;
+import io.micrometer.core.instrument.config.MeterFilter;
 
-import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.boot.util.LambdaSafe;
 
 /**
- * {@link BeanPostProcessor} to apply {@link MeterRegistryCustomizer customizers} and
- * {@link MeterBinder binters} and {@link Metrics#addRegistry global registration} to
- * {@link MeterRegistry meter registries}. This post processor intentionally skips
- * {@link CompositeMeterRegistry} with the assumptions that the registries it contains are
- * beans and will be customized directly.
+ * {@link BeanPostProcessor} to apply {@link MeterRegistryCustomizer customizers},
+ * {@link MeterFilter filters}, {@link MeterBinder binders} and {@link Metrics#addRegistry
+ * global registration} to {@link MeterRegistry meter registries}. This post processor
+ * intentionally skips {@link CompositeMeterRegistry} with the assumptions that the
+ * registries it contains are beans and will be customized directly.
  *
  * @author Jon Schneider
  * @author Phillip Webb
@@ -42,15 +42,19 @@ class MeterRegistryPostProcessor implements BeanPostProcessor {
 
 	private final Collection<MeterRegistryCustomizer<?>> customizers;
 
+	private final Collection<MeterFilter> filters;
+
 	private final Collection<MeterBinder> binders;
 
 	private final boolean addToGlobalRegistry;
 
-	MeterRegistryPostProcessor(ObjectProvider<Collection<MeterBinder>> binders,
-			ObjectProvider<Collection<MeterRegistryCustomizer<?>>> customizers,
+	MeterRegistryPostProcessor(Collection<MeterBinder> binders,
+			Collection<MeterFilter> filters,
+			Collection<MeterRegistryCustomizer<?>> customizers,
 			boolean addToGlobalRegistry) {
-		this.binders = binders.getIfAvailable(Collections::emptyList);
-		this.customizers = customizers.getIfAvailable(Collections::emptyList);
+		this.binders = (binders != null ? binders : Collections.emptyList());
+		this.filters = (filters != null ? filters : Collections.emptyList());
+		this.customizers = (customizers != null ? customizers : Collections.emptyList());
 		this.addToGlobalRegistry = addToGlobalRegistry;
 	}
 
@@ -74,6 +78,7 @@ class MeterRegistryPostProcessor implements BeanPostProcessor {
 		// Customizers must be applied before binders, as they may add custom tags or
 		// alter timer or summary configuration.
 		customize(registry);
+		addFilters(registry);
 		addBinders(registry);
 		if (this.addToGlobalRegistry && registry != Metrics.globalRegistry) {
 			Metrics.addRegistry(registry);
@@ -87,6 +92,10 @@ class MeterRegistryPostProcessor implements BeanPostProcessor {
 				.invoke((customizer) -> customizer.customize(registry));
 	}
 
+	private void addFilters(MeterRegistry registry) {
+		this.filters.forEach(registry.config()::meterFilter);
+	}
+
 	private void addBinders(MeterRegistry registry) {
 		this.binders.forEach((binder) -> binder.bindTo(registry));
 	}

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

@@ -22,6 +22,7 @@ import io.micrometer.core.annotation.Timed;
 import io.micrometer.core.instrument.Clock;
 import io.micrometer.core.instrument.MeterRegistry;
 import io.micrometer.core.instrument.binder.MeterBinder;
+import io.micrometer.core.instrument.config.MeterFilter;
 
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.actuate.autoconfigure.endpoint.condition.ConditionalOnEnabledEndpoint;
@@ -73,9 +74,11 @@ public class MetricsAutoConfiguration {
 	@Bean
 	public static MeterRegistryPostProcessor meterRegistryPostProcessor(
 			ObjectProvider<Collection<MeterBinder>> binders,
+			ObjectProvider<Collection<MeterFilter>> filters,
 			ObjectProvider<Collection<MeterRegistryCustomizer<?>>> customizers,
 			MetricsProperties properties) {
-		return new MeterRegistryPostProcessor(binders, customizers,
+		return new MeterRegistryPostProcessor(binders.getIfAvailable(),
+				filters.getIfAvailable(), customizers.getIfAvailable(),
 				properties.isUseGlobalRegistry());
 	}
 

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

@@ -17,24 +17,22 @@
 package org.springframework.boot.actuate.autoconfigure.metrics;
 
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.List;
 
 import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.MeterRegistry.Config;
 import io.micrometer.core.instrument.Metrics;
 import io.micrometer.core.instrument.binder.MeterBinder;
 import io.micrometer.core.instrument.composite.CompositeMeterRegistry;
+import io.micrometer.core.instrument.config.MeterFilter;
 import org.junit.Before;
 import org.junit.Test;
 import org.mockito.InOrder;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
-import org.springframework.beans.BeansException;
-import org.springframework.beans.factory.ObjectProvider;
-import org.springframework.util.Assert;
-
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.BDDMockito.given;
 import static org.mockito.Mockito.inOrder;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyZeroInteractions;
@@ -46,34 +44,37 @@ import static org.mockito.Mockito.verifyZeroInteractions;
  */
 public class MeterRegistryPostProcessorTests {
 
-	private List<MeterBinder> binderBeans = new ArrayList<>();
-
-	private List<MeterRegistryCustomizer<?>> customizerBeans = new ArrayList<>();
+	private List<MeterBinder> binders = new ArrayList<>();
 
-	private ObjectProvider<Collection<MeterBinder>> binders = TestObjectProvider
-			.of(this.binderBeans);
+	private List<MeterFilter> filters = new ArrayList<>();
 
-	private ObjectProvider<Collection<MeterRegistryCustomizer<?>>> customizers = TestObjectProvider
-			.of(this.customizerBeans);
+	private List<MeterRegistryCustomizer<?>> customizers = new ArrayList<>();
 
 	@Mock
 	private MeterBinder mockBinder;
 
+	@Mock
+	private MeterFilter mockFilter;
+
 	@Mock
 	private MeterRegistryCustomizer<MeterRegistry> mockCustomizer;
 
 	@Mock
 	private MeterRegistry mockRegistry;
 
+	@Mock
+	private Config mockConfig;
+
 	@Before
 	public void setup() {
 		MockitoAnnotations.initMocks(this);
+		given(this.mockRegistry.config()).willReturn(this.mockConfig);
 	}
 
 	@Test
 	public void postProcessWhenNotRegistryShouldReturnBean() {
 		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
-				this.binders, this.customizers, false);
+				this.binders, this.filters, this.customizers, false);
 		Object bean = new Object();
 		String beanName = "name";
 		assertThat(processor.postProcessBeforeInitialization(bean, beanName))
@@ -84,10 +85,10 @@ public class MeterRegistryPostProcessorTests {
 
 	@Test
 	public void postProcessorWhenCompositeShouldSkip() {
-		this.binderBeans.add(this.mockBinder);
-		this.customizerBeans.add(this.mockCustomizer);
+		this.binders.add(this.mockBinder);
+		this.customizers.add(this.mockCustomizer);
 		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
-				this.binders, this.customizers, false);
+				this.binders, this.filters, this.customizers, false);
 		assertThat(processor.postProcessAfterInitialization(new CompositeMeterRegistry(),
 				"name"));
 		verifyZeroInteractions(this.mockBinder, this.mockCustomizer);
@@ -95,38 +96,49 @@ public class MeterRegistryPostProcessorTests {
 
 	@Test
 	public void postProcessShouldApplyCustomizer() {
-		this.customizerBeans.add(this.mockCustomizer);
+		this.customizers.add(this.mockCustomizer);
 		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
-				this.binders, this.customizers, false);
+				this.binders, this.filters, this.customizers, false);
 		assertThat(processor.postProcessAfterInitialization(this.mockRegistry, "name"));
 		verify(this.mockCustomizer).customize(this.mockRegistry);
 	}
 
+	@Test
+	public void postProcessShouldApplyFilter() {
+		this.filters.add(this.mockFilter);
+		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
+				this.binders, this.filters, this.customizers, false);
+		assertThat(processor.postProcessAfterInitialization(this.mockRegistry, "name"));
+		verify(this.mockConfig).meterFilter(this.mockFilter);
+	}
+
 	@Test
 	public void postProcessShouldApplyBinder() {
-		this.binderBeans.add(this.mockBinder);
+		this.binders.add(this.mockBinder);
 		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
-				this.binders, this.customizers, false);
+				this.binders, this.filters, this.customizers, false);
 		assertThat(processor.postProcessAfterInitialization(this.mockRegistry, "name"));
 		verify(this.mockBinder).bindTo(this.mockRegistry);
 	}
 
 	@Test
-	public void postProcessShouldCustomizeBeforeApplyingBinder() {
-		this.binderBeans.add(this.mockBinder);
-		this.customizerBeans.add(this.mockCustomizer);
+	public void postProcessShouldBeCallInOrderCustomizeFilterBinder() {
+		this.customizers.add(this.mockCustomizer);
+		this.filters.add(this.mockFilter);
+		this.binders.add(this.mockBinder);
 		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
-				this.binders, this.customizers, false);
+				this.binders, this.filters, this.customizers, false);
 		processor.postProcessAfterInitialization(this.mockRegistry, "name");
-		InOrder ordered = inOrder(this.mockCustomizer, this.mockBinder);
+		InOrder ordered = inOrder(this.mockBinder, this.mockConfig, this.mockCustomizer);
 		ordered.verify(this.mockCustomizer).customize(this.mockRegistry);
+		ordered.verify(this.mockConfig).meterFilter(this.mockFilter);
 		ordered.verify(this.mockBinder).bindTo(this.mockRegistry);
 	}
 
 	@Test
 	public void postProcessWhenAddToGlobalRegistryShouldAddToGlobalRegistry() {
 		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
-				this.binders, this.customizers, true);
+				this.binders, this.filters, this.customizers, true);
 		try {
 			processor.postProcessAfterInitialization(this.mockRegistry, "name");
 			assertThat(Metrics.globalRegistry.getRegistries())
@@ -140,45 +152,10 @@ public class MeterRegistryPostProcessorTests {
 	@Test
 	public void postProcessWhenNotAddToGlobalRegistryShouldAddToGlobalRegistry() {
 		MeterRegistryPostProcessor processor = new MeterRegistryPostProcessor(
-				this.binders, this.customizers, false);
+				this.binders, this.filters, this.customizers, false);
 		processor.postProcessAfterInitialization(this.mockRegistry, "name");
 		assertThat(Metrics.globalRegistry.getRegistries())
 				.doesNotContain(this.mockRegistry);
 	}
 
-	private static class TestObjectProvider<T> implements ObjectProvider<T> {
-
-		private final T value;
-
-		TestObjectProvider(T value) {
-			this.value = value;
-		}
-
-		@Override
-		public T getObject() throws BeansException {
-			Assert.state(this.value != null, "No value");
-			return this.value;
-		}
-
-		@Override
-		public T getObject(Object... args) throws BeansException {
-			return this.value;
-		}
-
-		@Override
-		public T getIfAvailable() throws BeansException {
-			return this.value;
-		}
-
-		@Override
-		public T getIfUnique() throws BeansException {
-			throw new UnsupportedOperationException();
-		}
-
-		public static <T> TestObjectProvider<T> of(T value) {
-			return new TestObjectProvider<>(value);
-		}
-
-	}
-
 }