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-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)
+	}
+}