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"
+    ]
+  }
+}