Merge pull request #26001 from bono007

* pr/26001:
  Polish "Add auto-configuration for DiskSpaceMetrics"
  Add auto-configuration for DiskSpaceMetrics

Closes gh-26001

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

 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,8 +16,11 @@
 
 package org.springframework.boot.actuate.autoconfigure.metrics;
 
+import java.io.File;
+
 import io.micrometer.core.instrument.MeterRegistry;
 import io.micrometer.core.instrument.binder.jvm.ClassLoaderMetrics;
+import io.micrometer.core.instrument.binder.jvm.DiskSpaceMetrics;
 import io.micrometer.core.instrument.binder.jvm.JvmGcMetrics;
 import io.micrometer.core.instrument.binder.jvm.JvmMemoryMetrics;
 import io.micrometer.core.instrument.binder.jvm.JvmThreadMetrics;
@@ -66,4 +69,10 @@ public class JvmMetricsAutoConfiguration {
 		return new ClassLoaderMetrics();
 	}
 
+	@Bean
+	@ConditionalOnMissingBean
+	public DiskSpaceMetrics diskSpaceMetrics() {
+		return new DiskSpaceMetrics(new File("."));
+	}
+
 }

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

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,10 @@
 
 package org.springframework.boot.actuate.autoconfigure.metrics;
 
+import java.io.File;
+
 import io.micrometer.core.instrument.binder.jvm.ClassLoaderMetrics;
+import io.micrometer.core.instrument.binder.jvm.DiskSpaceMetrics;
 import io.micrometer.core.instrument.binder.jvm.JvmGcMetrics;
 import io.micrometer.core.instrument.binder.jvm.JvmMemoryMetrics;
 import io.micrometer.core.instrument.binder.jvm.JvmThreadMetrics;
@@ -24,7 +27,9 @@ import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.actuate.autoconfigure.metrics.test.MetricsRun;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.test.context.assertj.AssertableApplicationContext;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.boot.test.context.runner.ContextConsumer;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
@@ -35,6 +40,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  *
  * @author Andy Wilkinson
  * @author Stephane Nicoll
+ * @author Chris Bono
  */
 class JvmMetricsAutoConfigurationTests {
 
@@ -43,41 +49,43 @@ class JvmMetricsAutoConfigurationTests {
 
 	@Test
 	void autoConfiguresJvmMetrics() {
-		this.contextRunner.run(
-				(context) -> assertThat(context).hasSingleBean(JvmGcMetrics.class).hasSingleBean(JvmMemoryMetrics.class)
-						.hasSingleBean(JvmThreadMetrics.class).hasSingleBean(ClassLoaderMetrics.class));
+		this.contextRunner.run(assertMetricsBeans());
 	}
 
 	@Test
 	void allowsCustomJvmGcMetricsToBeUsed() {
 		this.contextRunner.withUserConfiguration(CustomJvmGcMetricsConfiguration.class)
-				.run((context) -> assertThat(context).hasSingleBean(JvmGcMetrics.class).hasBean("customJvmGcMetrics")
-						.hasSingleBean(JvmMemoryMetrics.class).hasSingleBean(JvmThreadMetrics.class)
-						.hasSingleBean(ClassLoaderMetrics.class));
+				.run(assertMetricsBeans().andThen((context) -> assertThat(context).hasBean("customJvmGcMetrics")));
 	}
 
 	@Test
 	void allowsCustomJvmMemoryMetricsToBeUsed() {
 		this.contextRunner.withUserConfiguration(CustomJvmMemoryMetricsConfiguration.class)
-				.run((context) -> assertThat(context).hasSingleBean(JvmGcMetrics.class)
-						.hasSingleBean(JvmMemoryMetrics.class).hasBean("customJvmMemoryMetrics")
-						.hasSingleBean(JvmThreadMetrics.class).hasSingleBean(ClassLoaderMetrics.class));
+				.run(assertMetricsBeans().andThen((context) -> assertThat(context).hasBean("customJvmMemoryMetrics")));
 	}
 
 	@Test
 	void allowsCustomJvmThreadMetricsToBeUsed() {
 		this.contextRunner.withUserConfiguration(CustomJvmThreadMetricsConfiguration.class)
-				.run((context) -> assertThat(context).hasSingleBean(JvmGcMetrics.class)
-						.hasSingleBean(JvmMemoryMetrics.class).hasSingleBean(JvmThreadMetrics.class)
-						.hasSingleBean(ClassLoaderMetrics.class).hasBean("customJvmThreadMetrics"));
+				.run(assertMetricsBeans().andThen((context) -> assertThat(context).hasBean("customJvmThreadMetrics")));
 	}
 
 	@Test
 	void allowsCustomClassLoaderMetricsToBeUsed() {
-		this.contextRunner.withUserConfiguration(CustomClassLoaderMetricsConfiguration.class)
-				.run((context) -> assertThat(context).hasSingleBean(JvmGcMetrics.class)
-						.hasSingleBean(JvmMemoryMetrics.class).hasSingleBean(JvmThreadMetrics.class)
-						.hasSingleBean(ClassLoaderMetrics.class).hasBean("customClassLoaderMetrics"));
+		this.contextRunner.withUserConfiguration(CustomClassLoaderMetricsConfiguration.class).run(
+				assertMetricsBeans().andThen((context) -> assertThat(context).hasBean("customClassLoaderMetrics")));
+	}
+
+	@Test
+	void allowsCustomDiskSpaceMetricsToBeUsed() {
+		this.contextRunner.withUserConfiguration(CustomDiskSpaceMetricsConfiguration.class)
+				.run(assertMetricsBeans().andThen((context) -> assertThat(context).hasBean("customDiskSpaceMetrics")));
+	}
+
+	private ContextConsumer<AssertableApplicationContext> assertMetricsBeans() {
+		return (context) -> assertThat(context).hasSingleBean(JvmGcMetrics.class).hasSingleBean(JvmMemoryMetrics.class)
+				.hasSingleBean(JvmThreadMetrics.class).hasSingleBean(ClassLoaderMetrics.class)
+				.hasSingleBean(DiskSpaceMetrics.class);
 	}
 
 	@Configuration(proxyBeanMethods = false)
@@ -120,4 +128,14 @@ class JvmMetricsAutoConfigurationTests {
 
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	static class CustomDiskSpaceMetricsConfiguration {
+
+		@Bean
+		DiskSpaceMetrics customDiskSpaceMetrics() {
+			return new DiskSpaceMetrics(new File(System.getProperty("user.dir")));
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-docs/src/docs/asciidoc/actuator/metrics.adoc

@@ -554,7 +554,7 @@ In most situations, the out-of-the-box defaults will provide sensible metrics th
 [[actuator.metrics.supported.jvm]]
 ==== JVM Metrics
 Auto-configuration will enable JVM Metrics using core Micrometer classes.
-JVM metrics are published under the `jvm.` meter name.
+JVM metrics are published under the `jvm.` and `disk.` meter names.
 
 The following JVM metrics are provided:
 
@@ -562,6 +562,7 @@ The following JVM metrics are provided:
 * Statistics related to garbage collection
 * Threads utilization
 * The Number of classes loaded/unloaded
+* Disk space available