Add support for caching to bind mounts when building images

When building an image using the Maven `spring-boot:build-image` goal or
the Gradle `bootBuildImage` task, the build and launch caches can be
configured to use a bind mount as an alternative to using a named
volume.

Closes gh-28387

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/build/AbstractBuildLog.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2023 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.
@@ -68,6 +68,12 @@ public abstract class AbstractBuildLog implements BuildLog {
 		log(" > Using build cache volume '" + buildCacheVolume + "'");
 	}
 
+	@Override
+	public void executingLifecycle(BuildRequest request, LifecycleVersion version, Cache buildCache) {
+		log(" > Executing lifecycle version " + version);
+		log(" > Using build cache " + buildCache);
+	}
+
 	@Override
 	public Consumer<LogUpdateEvent> runningPhase(BuildRequest request, String name) {
 		log();

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/build/BuildLog.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2023 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.
@@ -79,6 +79,14 @@ public interface BuildLog {
 	 */
 	void executingLifecycle(BuildRequest request, LifecycleVersion version, VolumeName buildCacheVolume);
 
+	/**
+	 * Log that the lifecycle is executing.
+	 * @param request the build request
+	 * @param version the lifecycle version
+	 * @param buildCache the build cache in use
+	 */
+	void executingLifecycle(BuildRequest request, LifecycleVersion version, Cache buildCache);
+
 	/**
 	 * Log that a specific phase is running.
 	 * @param request the build request

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/build/Cache.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2023 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.
@@ -18,6 +18,7 @@ package org.springframework.boot.buildpack.platform.build;
 
 import java.util.Objects;
 
+import org.springframework.boot.buildpack.platform.docker.type.VolumeName;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
 
@@ -37,7 +38,22 @@ public class Cache {
 		/**
 		 * A cache stored as a volume in the Docker daemon.
 		 */
-		VOLUME;
+		VOLUME("volume"),
+
+		/**
+		 * A cache stored as a bind mount.
+		 */
+		BIND("bind mount");
+
+		private final String description;
+
+		Format(String description) {
+			this.description = description;
+		}
+
+		public String getDescription() {
+			return this.description;
+		}
 
 	}
 
@@ -55,16 +71,44 @@ public class Cache {
 		return (this.format.equals(Format.VOLUME)) ? (Volume) this : null;
 	}
 
+	/**
+	 * Return the details of the cache if it is a bind cache.
+	 * @return the cache, or {@code null} if it is not a bind cache
+	 */
+	public Bind getBind() {
+		return (this.format.equals(Format.BIND)) ? (Bind) this : null;
+	}
+
 	/**
 	 * Create a new {@code Cache} that uses a volume with the provided name.
 	 * @param name the cache volume name
 	 * @return a new cache instance
 	 */
 	public static Cache volume(String name) {
+		Assert.notNull(name, "Name must not be null");
+		return new Volume(VolumeName.of(name));
+	}
+
+	/**
+	 * Create a new {@code Cache} that uses a volume with the provided name.
+	 * @param name the cache volume name
+	 * @return a new cache instance
+	 */
+	public static Cache volume(VolumeName name) {
 		Assert.notNull(name, "Name must not be null");
 		return new Volume(name);
 	}
 
+	/**
+	 * Create a new {@code Cache} that uses a bind mount with the provided source.
+	 * @param source the cache bind mount source
+	 * @return a new cache instance
+	 */
+	public static Cache bind(String source) {
+		Assert.notNull(source, "Source must not be null");
+		return new Bind(source);
+	}
+
 	@Override
 	public boolean equals(Object obj) {
 		if (this == obj) {
@@ -87,14 +131,18 @@ public class Cache {
 	 */
 	public static class Volume extends Cache {
 
-		private final String name;
+		private final VolumeName name;
 
-		Volume(String name) {
+		Volume(VolumeName name) {
 			super(Format.VOLUME);
 			this.name = name;
 		}
 
 		public String getName() {
+			return this.name.toString();
+		}
+
+		public VolumeName getVolumeName() {
 			return this.name;
 		}
 
@@ -120,6 +168,56 @@ public class Cache {
 			return result;
 		}
 
+		@Override
+		public String toString() {
+			return this.format.getDescription() + " '" + this.name + "'";
+		}
+
+	}
+
+	/**
+	 * Details of a cache stored in a bind mount.
+	 */
+	public static class Bind extends Cache {
+
+		private final String source;
+
+		Bind(String source) {
+			super(Format.BIND);
+			this.source = source;
+		}
+
+		public String getSource() {
+			return this.source;
+		}
+
+		@Override
+		public boolean equals(Object obj) {
+			if (this == obj) {
+				return true;
+			}
+			if (obj == null || getClass() != obj.getClass()) {
+				return false;
+			}
+			if (!super.equals(obj)) {
+				return false;
+			}
+			Bind other = (Bind) obj;
+			return Objects.equals(this.source, other.source);
+		}
+
+		@Override
+		public int hashCode() {
+			int result = super.hashCode();
+			result = 31 * result + ObjectUtils.nullSafeHashCode(this.source);
+			return result;
+		}
+
+		@Override
+		public String toString() {
+			return this.format.getDescription() + " '" + this.source + "'";
+		}
+
 	}
 
 }

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/build/Lifecycle.java

@@ -18,6 +18,7 @@ package org.springframework.boot.buildpack.platform.build;
 
 import java.io.Closeable;
 import java.io.IOException;
+import java.nio.file.Path;
 import java.util.function.Consumer;
 
 import com.sun.jna.Platform;
@@ -34,6 +35,7 @@ import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.buildpack.platform.docker.type.VolumeName;
 import org.springframework.boot.buildpack.platform.io.TarArchive;
 import org.springframework.util.Assert;
+import org.springframework.util.FileSystemUtils;
 
 /**
  * A buildpack lifecycle used to run the build {@link Phase phases} needed to package an
@@ -72,9 +74,9 @@ class Lifecycle implements Closeable {
 
 	private final VolumeName applicationVolume;
 
-	private final VolumeName buildCacheVolume;
+	private final Cache buildCache;
 
-	private final VolumeName launchCacheVolume;
+	private final Cache launchCache;
 
 	private final String applicationDirectory;
 
@@ -101,8 +103,8 @@ class Lifecycle implements Closeable {
 		this.platformVersion = getPlatformVersion(builder.getBuilderMetadata().getLifecycle());
 		this.layersVolume = createRandomVolumeName("pack-layers-");
 		this.applicationVolume = createRandomVolumeName("pack-app-");
-		this.buildCacheVolume = getBuildCacheVolumeName(request);
-		this.launchCacheVolume = getLaunchCacheVolumeName(request);
+		this.buildCache = getBuildCache(request);
+		this.launchCache = getLaunchCache(request);
 		this.applicationDirectory = getApplicationDirectory(request);
 	}
 
@@ -110,33 +112,27 @@ class Lifecycle implements Closeable {
 		return VolumeName.random(prefix);
 	}
 
-	private VolumeName getBuildCacheVolumeName(BuildRequest request) {
+	private Cache getBuildCache(BuildRequest request) {
 		if (request.getBuildCache() != null) {
-			return getVolumeName(request.getBuildCache());
+			return request.getBuildCache();
 		}
-		return createCacheVolumeName(request, "build");
+		return createVolumeCache(request, "build");
 	}
 
-	private VolumeName getLaunchCacheVolumeName(BuildRequest request) {
+	private Cache getLaunchCache(BuildRequest request) {
 		if (request.getLaunchCache() != null) {
-			return getVolumeName(request.getLaunchCache());
+			return request.getLaunchCache();
 		}
-		return createCacheVolumeName(request, "launch");
-	}
-
-	private VolumeName getVolumeName(Cache cache) {
-		if (cache.getVolume() != null) {
-			return VolumeName.of(cache.getVolume().getName());
-		}
-		return null;
+		return createVolumeCache(request, "launch");
 	}
 
 	private String getApplicationDirectory(BuildRequest request) {
 		return (request.getApplicationDirectory() != null) ? request.getApplicationDirectory() : Directory.APPLICATION;
 	}
 
-	private VolumeName createCacheVolumeName(BuildRequest request, String suffix) {
-		return VolumeName.basedOn(request.getName(), ImageReference::toLegacyString, "pack-cache-", "." + suffix, 6);
+	private Cache createVolumeCache(BuildRequest request, String suffix) {
+		return Cache.volume(
+				VolumeName.basedOn(request.getName(), ImageReference::toLegacyString, "pack-cache-", "." + suffix, 6));
 	}
 
 	private ApiVersion getPlatformVersion(BuilderMetadata.Lifecycle lifecycle) {
@@ -155,9 +151,14 @@ class Lifecycle implements Closeable {
 	void execute() throws IOException {
 		Assert.state(!this.executed, "Lifecycle has already been executed");
 		this.executed = true;
-		this.log.executingLifecycle(this.request, this.lifecycleVersion, this.buildCacheVolume);
+		this.log.executingLifecycle(this.request, this.lifecycleVersion, this.buildCache);
 		if (this.request.isCleanCache()) {
-			deleteVolume(this.buildCacheVolume);
+			if (this.buildCache.getVolume() != null) {
+				deleteVolume(this.buildCache.getVolume().getVolumeName());
+			}
+			if (this.buildCache.getBind() != null) {
+				deleteBind(this.buildCache.getBind().getSource());
+			}
 		}
 		run(createPhase());
 		this.log.executedLifecycle(this.request);
@@ -184,8 +185,8 @@ class Lifecycle implements Closeable {
 		phase.withArgs(this.request.getName());
 		phase.withBinding(Binding.from(this.layersVolume, Directory.LAYERS));
 		phase.withBinding(Binding.from(this.applicationVolume, this.applicationDirectory));
-		phase.withBinding(Binding.from(this.buildCacheVolume, Directory.CACHE));
-		phase.withBinding(Binding.from(this.launchCacheVolume, Directory.LAUNCH_CACHE));
+		phase.withBinding(Binding.from(getCacheBindingSource(this.buildCache), Directory.CACHE));
+		phase.withBinding(Binding.from(getCacheBindingSource(this.launchCache), Directory.LAUNCH_CACHE));
 		if (this.request.getBindings() != null) {
 			this.request.getBindings().forEach(phase::withBinding);
 		}
@@ -199,6 +200,10 @@ class Lifecycle implements Closeable {
 		return phase;
 	}
 
+	private String getCacheBindingSource(Cache cache) {
+		return (cache.getVolume() != null) ? cache.getVolume().getName() : cache.getBind().getSource();
+	}
+
 	private void configureDaemonAccess(Phase phase) {
 		if (this.dockerHost != null) {
 			if (this.dockerHost.isRemote()) {
@@ -269,6 +274,15 @@ class Lifecycle implements Closeable {
 		this.docker.volume().delete(name, true);
 	}
 
+	private void deleteBind(String source) {
+		try {
+			FileSystemUtils.deleteRecursively(Path.of(source));
+		}
+		catch (IOException ex) {
+			throw new IllegalStateException("Error cleaning bind mount directory '" + source + "'", ex);
+		}
+	}
+
 	/**
 	 * Common directories used by the various phases.
 	 */

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/build/BuildRequestTests.java

@@ -239,6 +239,14 @@ class BuildRequestTests {
 		assertThat(withCache.getBuildCache()).isEqualTo(Cache.volume("build-volume"));
 	}
 
+	@Test
+	void withBuildBindCacheAddsCache() throws IOException {
+		BuildRequest request = BuildRequest.forJarFile(writeTestJarFile("my-app-0.0.1.jar"));
+		BuildRequest withCache = request.withBuildCache(Cache.bind("/tmp/build-cache"));
+		assertThat(request.getBuildCache()).isNull();
+		assertThat(withCache.getBuildCache()).isEqualTo(Cache.bind("/tmp/build-cache"));
+	}
+
 	@Test
 	void withBuildVolumeCacheWhenCacheIsNullThrowsException() throws IOException {
 		BuildRequest request = BuildRequest.forJarFile(writeTestJarFile("my-app-0.0.1.jar"));
@@ -254,6 +262,14 @@ class BuildRequestTests {
 		assertThat(withCache.getLaunchCache()).isEqualTo(Cache.volume("launch-volume"));
 	}
 
+	@Test
+	void withLaunchBindCacheAddsCache() throws IOException {
+		BuildRequest request = BuildRequest.forJarFile(writeTestJarFile("my-app-0.0.1.jar"));
+		BuildRequest withCache = request.withLaunchCache(Cache.bind("/tmp/launch-cache"));
+		assertThat(request.getLaunchCache()).isNull();
+		assertThat(withCache.getLaunchCache()).isEqualTo(Cache.bind("/tmp/launch-cache"));
+	}
+
 	@Test
 	void withLaunchVolumeCacheWhenCacheIsNullThrowsException() throws IOException {
 		BuildRequest request = BuildRequest.forJarFile(writeTestJarFile("my-app-0.0.1.jar"));

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/build/LifecycleTests.java

@@ -218,6 +218,18 @@ class LifecycleTests {
 		assertThat(this.out.toString()).contains("Successfully built image 'docker.io/library/my-application:latest'");
 	}
 
+	@Test
+	void executeWithCacheBindMountsExecutesPhases() throws Exception {
+		given(this.docker.container().create(any())).willAnswer(answerWithGeneratedContainerId());
+		given(this.docker.container().create(any(), any())).willAnswer(answerWithGeneratedContainerId());
+		given(this.docker.container().wait(any())).willReturn(ContainerStatus.of(0, null));
+		BuildRequest request = getTestRequest().withBuildCache(Cache.bind("/tmp/build-cache"))
+			.withLaunchCache(Cache.bind("/tmp/launch-cache"));
+		createLifecycle(request).execute();
+		assertPhaseWasRun("creator", withExpectedConfig("lifecycle-creator-cache-bind-mounts.json"));
+		assertThat(this.out.toString()).contains("Successfully built image 'docker.io/library/my-application:latest'");
+	}
+
 	@Test
 	void executeWithCreatedDateExecutesPhases() throws Exception {
 		given(this.docker.container().create(any())).willAnswer(answerWithGeneratedContainerId());

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/build/PrintStreamBuildLogTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2023 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.
@@ -67,7 +67,7 @@ class PrintStreamBuildLogTests {
 		Consumer<TotalProgressEvent> pullRunImageConsumer = log.pullingImage(runImageReference, ImageType.RUNNER);
 		pullRunImageConsumer.accept(new TotalProgressEvent(100));
 		log.pulledImage(runImage, ImageType.RUNNER);
-		log.executingLifecycle(request, LifecycleVersion.parse("0.5"), VolumeName.of("pack-abc.cache"));
+		log.executingLifecycle(request, LifecycleVersion.parse("0.5"), Cache.volume(VolumeName.of("pack-abc.cache")));
 		Consumer<LogUpdateEvent> phase1Consumer = log.runningPhase(request, "alphabet");
 		phase1Consumer.accept(mockLogEvent("one"));
 		phase1Consumer.accept(mockLogEvent("two"));

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/test/resources/org/springframework/boot/buildpack/platform/build/lifecycle-creator-cache-bind-mounts.json

@@ -0,0 +1,39 @@
+{
+  "User": "root",
+  "Image": "pack.local/ephemeral-builder",
+  "Cmd": [
+    "/cnb/lifecycle/creator",
+    "-app",
+    "/workspace",
+    "-platform",
+    "/platform",
+    "-run-image",
+    "docker.io/cloudfoundry/run:latest",
+    "-layers",
+    "/layers",
+    "-cache-dir",
+    "/cache",
+    "-launch-cache",
+    "/launch-cache",
+    "-daemon",
+    "docker.io/library/my-application:latest"
+  ],
+  "Env": [
+    "CNB_PLATFORM_API=0.8"
+  ],
+  "Labels": {
+    "author": "spring-boot"
+  },
+  "HostConfig": {
+    "Binds": [
+      "/var/run/docker.sock:/var/run/docker.sock",
+      "pack-layers-aaaaaaaaaa:/layers",
+      "pack-app-aaaaaaaaaa:/workspace",
+      "/tmp/build-cache:/cache",
+      "/tmp/launch-cache:/launch-cache"
+    ],
+    "SecurityOpt" : [
+      "label=disable"
+    ]
+  }
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/asciidoc/packaging-oci-image.adoc

@@ -440,6 +440,20 @@ include::../gradle/packaging/boot-build-image-caches.gradle[tags=caches]
 include::../gradle/packaging/boot-build-image-caches.gradle.kts[tags=caches]
 ----
 
+The caches can be configured to use bind mounts instead of named volumes, as shown in the following example:
+
+[source,groovy,indent=0,subs="verbatim,attributes",role="primary"]
+.Groovy
+----
+include::../gradle/packaging/boot-build-image-bind-caches.gradle[tags=caches]
+----
+
+[source,kotlin,indent=0,subs="verbatim,attributes",role="secondary"]
+.Kotlin
+----
+include::../gradle/packaging/boot-build-image-bind-caches.gradle.kts[tags=caches]
+----
+
 [[build-image.examples.docker]]
 === Docker Configuration
 

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/gradle/packaging/boot-build-image-bind-caches.gradle

@@ -0,0 +1,30 @@
+plugins {
+	id 'java'
+	id 'org.springframework.boot' version '{gradle-project-version}'
+}
+
+tasks.named("bootJar") {
+	mainClass = 'com.example.ExampleApplication'
+}
+
+// tag::caches[]
+tasks.named("bootBuildImage") {
+	buildCache {
+		bind {
+			source = "/tmp/cache-${rootProject.name}.build"
+		}
+	}
+	launchCache {
+		bind {
+			source = "/tmp/cache-${rootProject.name}.launch"
+		}
+	}
+}
+// end::caches[]
+
+tasks.register("bootBuildImageCaches") {
+	doFirst {
+		bootBuildImage.buildCache.asCache().with { println "buildCache=$source" }
+		bootBuildImage.launchCache.asCache().with { println "launchCache=$source" }
+	}
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/gradle/packaging/boot-build-image-bind-caches.gradle.kts

@@ -0,0 +1,28 @@
+import org.springframework.boot.gradle.tasks.bundling.BootBuildImage
+
+plugins {
+	java
+	id("org.springframework.boot") version "{gradle-project-version}"
+}
+
+// tag::caches[]
+tasks.named<BootBuildImage>("bootBuildImage") {
+	buildCache {
+		bind {
+			source.set("/tmp/cache-${rootProject.name}.build")
+		}
+	}
+	launchCache {
+		bind {
+			source.set("/tmp/cache-${rootProject.name}.launch")
+		}
+	}
+}
+// end::caches[]
+
+tasks.register("bootBuildImageCaches") {
+	doFirst {
+		println("buildCache=" + tasks.getByName<BootBuildImage>("bootBuildImage").buildCache.asCache().bind.source)
+		println("launchCache=" + tasks.getByName<BootBuildImage>("bootBuildImage").launchCache.asCache().bind.source)
+	}
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/CacheSpec.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2021-2022 the original author or authors.
+ * Copyright 2021-2023 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.
@@ -60,6 +60,19 @@ public class CacheSpec {
 		this.cache = Cache.volume(spec.getName().get());
 	}
 
+	/**
+	 * Configures a bind cache using the given {@code action}.
+	 * @param action the action
+	 */
+	public void bind(Action<BindCacheSpec> action) {
+		if (this.cache != null) {
+			throw new GradleException("Each image building cache can be configured only once");
+		}
+		BindCacheSpec spec = this.objectFactory.newInstance(BindCacheSpec.class);
+		action.execute(spec);
+		this.cache = Cache.bind(spec.getSource().get());
+	}
+
 	/**
 	 * Configuration for an image building cache stored in a Docker volume.
 	 */
@@ -74,4 +87,18 @@ public class CacheSpec {
 
 	}
 
+	/**
+	 * Configuration for an image building cache stored in a bind mount.
+	 */
+	public abstract static class BindCacheSpec {
+
+		/**
+		 * Returns the source of the cache.
+		 * @return the cache source
+		 */
+		@Input
+		public abstract Property<String> getSource();
+
+	}
+
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/docs/PackagingDocumentationTests.java

@@ -339,6 +339,14 @@ class PackagingDocumentationTests {
 			.containsPattern("launchCache=cache-gradle-[\\d]+.launch");
 	}
 
+	@TestTemplate
+	void bootBuildImageWithBindCaches() {
+		BuildResult result = this.gradleBuild.script("src/docs/gradle/packaging/boot-build-image-bind-caches")
+			.build("bootBuildImageCaches");
+		assertThat(result.getOutput()).containsPattern("buildCache=/tmp/cache-gradle-[\\d]+.build")
+			.containsPattern("launchCache=/tmp/cache-gradle-[\\d]+.launch");
+	}
+
 	protected void jarFile(File file) throws IOException {
 		try (JarOutputStream jar = new JarOutputStream(new FileOutputStream(file))) {
 			jar.putNextEntry(new ZipEntry("META-INF/MANIFEST.MF"));

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/tasks/bundling/BootBuildImageIntegrationTests.java

@@ -50,6 +50,7 @@ import org.springframework.boot.gradle.junit.GradleCompatibility;
 import org.springframework.boot.testsupport.gradle.testkit.GradleBuild;
 import org.springframework.boot.testsupport.junit.DisabledOnOs;
 import org.springframework.boot.testsupport.testcontainers.DisabledIfDockerUnavailable;
+import org.springframework.util.FileSystemUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -297,6 +298,26 @@ class BootBuildImageIntegrationTests {
 		deleteVolumes("cache-" + projectName + ".build", "cache-" + projectName + ".launch");
 	}
 
+	@TestTemplate
+	void buildsImageWithBindCaches() throws IOException {
+		writeMainClass();
+		writeLongNameResource();
+		BuildResult result = this.gradleBuild.build("bootBuildImage");
+		String projectName = this.gradleBuild.getProjectDir().getName();
+		assertThat(result.task(":bootBuildImage").getOutcome()).isEqualTo(TaskOutcome.SUCCESS);
+		assertThat(result.getOutput()).contains("docker.io/library/" + projectName);
+		assertThat(result.getOutput()).contains("---> Test Info buildpack building");
+		assertThat(result.getOutput()).contains("---> Test Info buildpack done");
+		removeImages(projectName);
+		String tempDir = System.getProperty("java.io.tmpdir");
+		Path buildCachePath = Paths.get(tempDir, "junit-image-cache-" + projectName + "-build");
+		Path launchCachePath = Paths.get(tempDir, "junit-image-cache-" + projectName + "-launch");
+		assertThat(buildCachePath).exists().isDirectory();
+		assertThat(launchCachePath).exists().isDirectory();
+		FileSystemUtils.deleteRecursively(buildCachePath);
+		FileSystemUtils.deleteRecursively(launchCachePath);
+	}
+
 	@TestTemplate
 	void buildsImageWithCreatedDate() throws IOException {
 		writeMainClass();

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootBuildImageIntegrationTests-buildsImageWithBindCaches.gradle

@@ -0,0 +1,24 @@
+plugins {
+	id 'java'
+	id 'org.springframework.boot' version '{version}'
+}
+
+java {
+	sourceCompatibility = '1.8'
+	targetCompatibility = '1.8'
+}
+
+bootBuildImage {
+	builder = "projects.registry.vmware.com/springboot/spring-boot-cnb-builder:0.0.2"
+	pullPolicy = "IF_NOT_PRESENT"
+	buildCache {
+		bind {
+			source = System.getProperty('java.io.tmpdir') + "/junit-image-cache-${rootProject.name}-build"
+		}
+	}
+	launchCache {
+		bind {
+			source = System.getProperty('java.io.tmpdir') + "/junit-image-cache-${rootProject.name}-launch"
+		}
+	}
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/resources/org/springframework/boot/gradle/tasks/bundling/BootBuildImageIntegrationTests-failsWhenCachesAreConfiguredTwice.gradle

@@ -12,10 +12,10 @@ bootBuildImage {
 	builder = "projects.registry.vmware.com/springboot/spring-boot-cnb-builder:0.0.2"
 	buildCache {
 		volume {
-			name = "build-cache-volume1"
+			name = "build-cache-volume"
 		}
-		volume {
-			name = "build-cache-volum2"
+		bind {
+			name = "/tmp/build-cache-bind"
 		}
 	}
 }

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/docs/asciidoc/packaging-oci-image.adoc

@@ -420,6 +420,13 @@ The cache volumes can be configured to use alternative names to give more contro
 include::../maven/packaging-oci-image/caches-pom.xml[tags=caches]
 ----
 
+The caches can be configured to use bind mounts instead of named volumes, as shown in the following example:
+
+[source,xml,indent=0,subs="verbatim,attributes",tabsize=4]
+----
+include::../maven/packaging-oci-image/bind-caches-pom.xml[tags=caches]
+----
+
 [[build-image.examples.docker]]
 === Docker Configuration
 

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/docs/maven/packaging-oci-image/bind-caches-pom.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- tag::caches[] -->
+<project>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+				<configuration>
+					<image>
+						<buildCache>
+							<bind>
+								<source>/tmp/cache-${project.artifactId}.build</source>
+							</bind>
+						</buildCache>
+						<launchCache>
+							<bind>
+								<source>/tmp/cache-${project.artifactId}.launch</source>
+							</bind>
+						</launchCache>
+					</image>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+</project>
+<!-- end::caches[] -->

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/java/org/springframework/boot/maven/BuildImageTests.java

@@ -37,6 +37,7 @@ import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.buildpack.platform.docker.type.VolumeName;
 import org.springframework.boot.testsupport.junit.DisabledOnOs;
 import org.springframework.boot.testsupport.testcontainers.DisabledIfDockerUnavailable;
+import org.springframework.util.FileSystemUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -385,19 +386,41 @@ class BuildImageTests extends AbstractArchiveIntegrationTests {
 	@TestTemplate
 	void whenBuildImageIsInvokedWithVolumeCaches(MavenBuild mavenBuild) {
 		String testBuildId = randomString();
-		mavenBuild.project("build-image-caches")
+		mavenBuild.project("build-image-volume-caches")
 			.goals("package")
 			.systemProperty("spring-boot.build-image.pullPolicy", "IF_NOT_PRESENT")
 			.systemProperty("test-build-id", testBuildId)
 			.execute((project) -> {
 				assertThat(buildLog(project)).contains("Building image")
-					.contains("docker.io/library/build-image-caches:0.0.1.BUILD-SNAPSHOT")
+					.contains("docker.io/library/build-image-volume-caches:0.0.1.BUILD-SNAPSHOT")
 					.contains("Successfully built image");
-				removeImage("build-image-caches", "0.0.1.BUILD-SNAPSHOT");
+				removeImage("build-image-volume-caches", "0.0.1.BUILD-SNAPSHOT");
 				deleteVolumes("cache-" + testBuildId + ".build", "cache-" + testBuildId + ".launch");
 			});
 	}
 
+	@TestTemplate
+	void whenBuildImageIsInvokedWithBindCaches(MavenBuild mavenBuild) {
+		String testBuildId = randomString();
+		mavenBuild.project("build-image-bind-caches")
+			.goals("package")
+			.systemProperty("spring-boot.build-image.pullPolicy", "IF_NOT_PRESENT")
+			.systemProperty("test-build-id", testBuildId)
+			.execute((project) -> {
+				assertThat(buildLog(project)).contains("Building image")
+					.contains("docker.io/library/build-image-bind-caches:0.0.1.BUILD-SNAPSHOT")
+					.contains("Successfully built image");
+				removeImage("build-image-bind-caches", "0.0.1.BUILD-SNAPSHOT");
+				String tempDir = System.getProperty("java.io.tmpdir");
+				Path buildCachePath = Paths.get(tempDir, "junit-image-cache-" + testBuildId + "-build");
+				Path launchCachePath = Paths.get(tempDir, "junit-image-cache-" + testBuildId + "-launch");
+				assertThat(buildCachePath).exists().isDirectory();
+				assertThat(launchCachePath).exists().isDirectory();
+				FileSystemUtils.deleteRecursively(buildCachePath);
+				FileSystemUtils.deleteRecursively(launchCachePath);
+			});
+	}
+
 	@TestTemplate
 	void whenBuildImageIsInvokedWithCreatedDate(MavenBuild mavenBuild) {
 		String testBuildId = randomString();

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/build-image-bind-caches/pom.xml

@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>build-image-bind-caches</artifactId>
+	<version>0.0.1.BUILD-SNAPSHOT</version>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<maven.compiler.source>@java.version@</maven.compiler.source>
+		<maven.compiler.target>@java.version@</maven.compiler.target>
+	</properties>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<executions>
+					<execution>
+						<goals>
+							<goal>build-image-no-fork</goal>
+						</goals>
+						<configuration>
+							<image>
+								<builder>projects.registry.vmware.com/springboot/spring-boot-cnb-builder:0.0.2</builder>
+								<buildCache>
+									<bind>
+										<source>${java.io.tmpdir}/junit-image-cache-${test-build-id}-build</source>
+									</bind>
+								</buildCache>
+								<launchCache>
+									<bind>
+										<source>${java.io.tmpdir}/junit-image-cache-${test-build-id}-launch</source>
+									</bind>
+								</launchCache>
+							</image>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+</project>

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/build-image-bind-caches/src/main/java/org/test/SampleApplication.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2023 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.

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/build-image-volume-caches/pom.xml

@@ -3,7 +3,7 @@
 		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>org.springframework.boot.maven.it</groupId>
-	<artifactId>build-image-caches</artifactId>
+	<artifactId>build-image-volume-caches</artifactId>
 	<version>0.0.1.BUILD-SNAPSHOT</version>
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/build-image-volume-caches/src/main/java/org/test/SampleApplication.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2012-2023 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.
+ * 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 org.test;
+
+public class SampleApplication {
+
+	public static void main(String[] args) throws Exception {
+		System.out.println("Launched");
+		synchronized(args) {
+			args.wait(); // Prevent exit
+		}
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/CacheInfo.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2023 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.
@@ -32,8 +32,8 @@ public class CacheInfo {
 	public CacheInfo() {
 	}
 
-	CacheInfo(VolumeCacheInfo volumeCacheInfo) {
-		this.cache = Cache.volume(volumeCacheInfo.getName());
+	private CacheInfo(Cache cache) {
+		this.cache = cache;
 	}
 
 	public void setVolume(VolumeCacheInfo info) {
@@ -41,10 +41,23 @@ public class CacheInfo {
 		this.cache = Cache.volume(info.getName());
 	}
 
+	public void setBind(BindCacheInfo info) {
+		Assert.state(this.cache == null, "Each image building cache can be configured only once");
+		this.cache = Cache.bind(info.getSource());
+	}
+
 	Cache asCache() {
 		return this.cache;
 	}
 
+	static CacheInfo fromVolume(VolumeCacheInfo cacheInfo) {
+		return new CacheInfo(Cache.volume(cacheInfo.getName()));
+	}
+
+	static CacheInfo fromBind(BindCacheInfo cacheInfo) {
+		return new CacheInfo(Cache.bind(cacheInfo.getSource()));
+	}
+
 	/**
 	 * Encapsulates configuration of an image building cache stored in a volume.
 	 */
@@ -69,4 +82,28 @@ public class CacheInfo {
 
 	}
 
+	/**
+	 * Encapsulates configuration of an image building cache stored in a bind mount.
+	 */
+	public static class BindCacheInfo {
+
+		private String source;
+
+		public BindCacheInfo() {
+		}
+
+		BindCacheInfo(String name) {
+			this.source = name;
+		}
+
+		public String getSource() {
+			return this.source;
+		}
+
+		void setSource(String source) {
+			this.source = source;
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/test/java/org/springframework/boot/maven/ImageTests.java

@@ -34,6 +34,7 @@ import org.springframework.boot.buildpack.platform.docker.type.Binding;
 import org.springframework.boot.buildpack.platform.docker.type.ImageReference;
 import org.springframework.boot.buildpack.platform.io.Owner;
 import org.springframework.boot.buildpack.platform.io.TarArchive;
+import org.springframework.boot.maven.CacheInfo.BindCacheInfo;
 import org.springframework.boot.maven.CacheInfo.VolumeCacheInfo;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -170,21 +171,37 @@ class ImageTests {
 	}
 
 	@Test
-	void getBuildRequestWhenHasBuildVolumeCacheUsesCache() {
+	void getBuildRequestWhenHasBuildCacheVolumeUsesCache() {
 		Image image = new Image();
-		image.buildCache = new CacheInfo(new VolumeCacheInfo("build-cache-vol"));
+		image.buildCache = CacheInfo.fromVolume(new VolumeCacheInfo("build-cache-vol"));
 		BuildRequest request = image.getBuildRequest(createArtifact(), mockApplicationContent());
 		assertThat(request.getBuildCache()).isEqualTo(Cache.volume("build-cache-vol"));
 	}
 
 	@Test
-	void getBuildRequestWhenHasLaunchVolumeCacheUsesCache() {
+	void getBuildRequestWhenHasLaunchCacheVolumeUsesCache() {
 		Image image = new Image();
-		image.launchCache = new CacheInfo(new VolumeCacheInfo("launch-cache-vol"));
+		image.launchCache = CacheInfo.fromVolume(new VolumeCacheInfo("launch-cache-vol"));
 		BuildRequest request = image.getBuildRequest(createArtifact(), mockApplicationContent());
 		assertThat(request.getLaunchCache()).isEqualTo(Cache.volume("launch-cache-vol"));
 	}
 
+	@Test
+	void getBuildRequestWhenHasBuildCacheBindUsesCache() {
+		Image image = new Image();
+		image.buildCache = CacheInfo.fromBind(new BindCacheInfo("build-cache-dir"));
+		BuildRequest request = image.getBuildRequest(createArtifact(), mockApplicationContent());
+		assertThat(request.getBuildCache()).isEqualTo(Cache.bind("build-cache-dir"));
+	}
+
+	@Test
+	void getBuildRequestWhenHasLaunchCacheBindUsesCache() {
+		Image image = new Image();
+		image.launchCache = CacheInfo.fromBind(new BindCacheInfo("launch-cache-dir"));
+		BuildRequest request = image.getBuildRequest(createArtifact(), mockApplicationContent());
+		assertThat(request.getLaunchCache()).isEqualTo(Cache.bind("launch-cache-dir"));
+	}
+
 	@Test
 	void getBuildRequestWhenHasCreatedDateUsesCreatedDate() {
 		Image image = new Image();