Retain Architecture config in ephemeral builder images

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/docker/type/Image.java

@@ -32,6 +32,7 @@
  * Image details as returned from {@code Docker inspect}.
  *
  * @author Phillip Webb
+ * @author Scott Frederick
  * @since 2.3.0
  */
 public class Image extends MappedObject {
@@ -40,8 +41,12 @@ public class Image extends MappedObject {
 
 	private final ImageConfig config;
 
+	private final String rootFsType;
+
 	private final List<LayerId> layers;
 
+	private final String architecture;
+
 	private final String os;
 
 	private final String created;
@@ -50,7 +55,9 @@ public class Image extends MappedObject {
 		super(node, MethodHandles.lookup());
 		this.digests = getDigests(getNode().at("/RepoDigests"));
 		this.config = new ImageConfig(getNode().at("/Config"));
+		this.rootFsType = valueAt("/RootFS/Type", String.class);
 		this.layers = extractLayers(valueAt("/RootFS/Layers", String[].class));
+		this.architecture = valueAt("/Architecture", String.class);
 		this.os = valueAt("/Os", String.class);
 		this.created = valueAt("/Created", String.class);
 	}
@@ -87,6 +94,14 @@ public ImageConfig getConfig() {
 		return this.config;
 	}
 
+	/**
+	 * Return the type of the root FS.
+	 * @return the root FS type
+	 */
+	public String getRootFsType() {
+		return this.rootFsType;
+	}
+
 	/**
 	 * Return the layer IDs contained in the image.
 	 * @return the layer IDs.
@@ -95,6 +110,14 @@ public List<LayerId> getLayers() {
 		return this.layers;
 	}
 
+	/**
+	 * Return the architecture of the image.
+	 * @return the image architecture
+	 */
+	public String getArchitecture() {
+		return this.architecture;
+	}
+
 	/**
 	 * Return the OS of the image.
 	 * @return the image OS

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/docker/type/ImageArchive.java

@@ -74,18 +74,21 @@ public class ImageArchive implements TarArchive {
 
 	private final ImageReference tag;
 
+	private final String architecture;
+
 	private final String os;
 
 	private final List<LayerId> existingLayers;
 
 	private final List<Layer> newLayers;
 
-	ImageArchive(ObjectMapper objectMapper, ImageConfig imageConfig, Instant createDate, ImageReference tag, String os,
-			List<LayerId> existingLayers, List<Layer> newLayers) {
+	ImageArchive(ObjectMapper objectMapper, ImageConfig imageConfig, Instant createDate, ImageReference tag,
+			String architecture, String os, List<LayerId> existingLayers, List<Layer> newLayers) {
 		this.objectMapper = objectMapper;
 		this.imageConfig = imageConfig;
 		this.createDate = createDate;
 		this.tag = tag;
+		this.architecture = architecture;
 		this.os = os;
 		this.existingLayers = existingLayers;
 		this.newLayers = newLayers;
@@ -164,11 +167,12 @@ private String writeConfig(Layout writer, List<LayerId> writtenLayers) throws IO
 
 	private ObjectNode createConfig(List<LayerId> writtenLayers) {
 		ObjectNode config = this.objectMapper.createObjectNode();
-		config.set("config", this.imageConfig.getNodeCopy());
-		config.set("created", config.textNode(getCreatedDate()));
-		config.set("history", createHistory(writtenLayers));
-		config.set("os", config.textNode(this.os));
-		config.set("rootfs", createRootFs(writtenLayers));
+		config.set("Config", this.imageConfig.getNodeCopy());
+		config.set("Created", config.textNode(getCreatedDate()));
+		config.set("History", createHistory(writtenLayers));
+		config.set("Architecture", config.textNode(this.architecture));
+		config.set("Os", config.textNode(this.os));
+		config.set("RootFS", createRootFs(writtenLayers));
 		return config;
 	}
 
@@ -263,8 +267,9 @@ private Update(Image image) {
 		private ImageArchive applyTo(IOConsumer<Update> update) throws IOException {
 			update.accept(this);
 			Instant createDate = (this.createDate != null) ? this.createDate : WINDOWS_EPOCH_PLUS_SECOND;
-			return new ImageArchive(SharedObjectMapper.get(), this.config, createDate, this.tag, this.image.getOs(),
-					this.image.getLayers(), Collections.unmodifiableList(this.newLayers));
+			return new ImageArchive(SharedObjectMapper.get(), this.config, createDate, this.tag,
+					this.image.getArchitecture(), this.image.getOs(), this.image.getLayers(),
+					Collections.unmodifiableList(this.newLayers));
 		}
 
 		/**

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/docker/type/ImageArchiveTests.java

@@ -78,7 +78,7 @@ private void assertExpectedLayer(TarArchiveEntry entry, byte[] content) throws E
 	}
 
 	private void assertExpectedConfig(TarArchiveEntry entry, byte[] content) throws Exception {
-		assertThat(entry.getName()).isEqualTo("682f8d24b9d9c313d1190a0e955dcb5e65ec9beea40420999839c6f0cbb38382.json");
+		assertThat(entry.getName()).isEqualTo("974b1da0e6ca36b645fd11a5e35b20924f0a6348ecef5884d14531f14dcb732b.json");
 		String actualJson = new String(content, StandardCharsets.UTF_8);
 		String expectedJson = StreamUtils.copyToString(getContent("image-archive-config.json"), StandardCharsets.UTF_8);
 		JSONAssert.assertEquals(expectedJson, actualJson, false);

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/docker/type/ImageTests.java

@@ -50,6 +50,12 @@ void getConfigLabelsReturnsLabels() throws Exception {
 		assertThat(labels).contains(entry("io.buildpacks.stack.id", "org.cloudfoundry.stacks.cflinuxfs3"));
 	}
 
+	@Test
+	void getRootFsTypeReturnsRootFsType() throws Exception {
+		Image image = getImage();
+		assertThat(image.getRootFsType()).isEqualTo("layers");
+	}
+
 	@Test
 	void getLayersReturnsImageLayers() throws Exception {
 		Image image = getImage();
@@ -61,6 +67,12 @@ void getLayersReturnsImageLayers() throws Exception {
 			.hasToString("sha256:5f70bf18a086007016e948b04aed3b82103a36bea41755b6cddfaf10ace3c6ef");
 	}
 
+	@Test
+	void getArchitectureReturnsArchitecture() throws Exception {
+		Image image = getImage();
+		assertThat(image.getArchitecture()).isEqualTo("amd64");
+	}
+
 	@Test
 	void getOsReturnsOs() throws Exception {
 		Image image = getImage();

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/test/resources/org/springframework/boot/buildpack/platform/docker/type/image-archive-config.json

@@ -1,5 +1,5 @@
 {
-	"config": {
+	"Config": {
 		"Hostname": "",
 		"Domainname": "",
 		"User": "vcap",
@@ -25,8 +25,8 @@
 			"io.buildpacks.stack.id": "org.cloudfoundry.stacks.cflinuxfs3"
 		}
 	},
-	"created": "1980-01-01T00:00:01Z",
-	"history": [
+	"Created": "1980-01-01T00:00:01Z",
+	"History": [
 		{
 
 		},
@@ -169,8 +169,9 @@
 
 		}
 	],
-	"os": "linux",
-	"rootfs": {
+  "Architecture": "amd64",
+	"Os": "linux",
+	"RootFS": {
 		"diff_ids": [
 			"sha256:733a8e5ce32984099ef675fce04730f6e2a6dcfdf5bd292fea01a8f936265342",
 			"sha256:7755b972f0b4f49de73ef5114fb3ba9c69d80f217e80da99f56f0d0a5dcb3d70",

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/test/resources/org/springframework/boot/buildpack/platform/docker/type/image-archive-manifest.json

@@ -1,6 +1,6 @@
 [
 	{
-		"Config": "682f8d24b9d9c313d1190a0e955dcb5e65ec9beea40420999839c6f0cbb38382.json",
+		"Config": "974b1da0e6ca36b645fd11a5e35b20924f0a6348ecef5884d14531f14dcb732b.json",
 		"Layers": [
 			"blank_0",
 			"blank_1",