build: introduce OUTPUT_TARBALL_FILELIST=yes to include LK's --format tar output and its filelist

- useful during development for:
  - debugging esoteric issue with file permissions
  - checking the space usage distribution, so we can slim down where needed

Signed-off-by: Ricardo Pardini <[email protected]>

Author: rpardini

bash/linuxkit.sh

@@ -84,15 +84,19 @@ function linuxkit_build() {
 	declare -a lk_args=(
 		"--docker"
 		"--arch" "${kernel_info['DOCKER_ARCH']}"
-		"--format" "kernel+initrd"
 		"--name" "hook"
 		"--cache" "${lk_cache_dir}"
 		"--dir" "${lk_output_dir}"
 		"hook.${inventory_id}.yaml" # the linuxkit configuration file
 	)
 
+	if [[ "${OUTPUT_TARBALL_FILELIST:-"no"}" == "yes" ]]; then
+		log info "OUTPUT_TARBALL_FILELIST=yes; Building Hook (tar/filelist) with kernel ${inventory_id} using linuxkit: ${lk_args[*]}"
+		"${linuxkit_bin}" build "--format" "tar" "${lk_args[@]}"
+	fi
+
 	log info "Building Hook with kernel ${inventory_id} using linuxkit: ${lk_args[*]}"
-	"${linuxkit_bin}" build "${lk_args[@]}"
+	"${linuxkit_bin}" build "--format" "kernel+initrd" "${lk_args[@]}"
 
 	if [[ "${LK_RUN}" == "qemu" ]]; then
 		linuxkit_run_qemu
@@ -137,6 +141,13 @@ function linuxkit_build() {
 	rm -rf "${dtbs_tmp_dir}"
 	rm "${lk_output_dir}/dtbs-${OUTPUT_ID}.tar.gz"
 
+	if [[ "${OUTPUT_TARBALL_FILELIST:-"no"}" == "yes" ]]; then
+		log info "OUTPUT_TARBALL_FILELIST=yes; including tar and filelist in output."
+		mv -v "${lk_output_dir}/hook.tar" "out/hook/hook_rootfs_${OUTPUT_ID}.tar"
+		tar --list -vf "out/hook/hook_rootfs_${OUTPUT_ID}.tar" > "out/hook/hook_rootfs_${OUTPUT_ID}.filelist"
+	fi
+
+	# finally clean up the hook-specific out dir
 	rm -rf "${lk_output_dir}"
 
 	# tar the files into out/hook.tar in such a way that vmlinuz and initramfs are at the root of the tar; pigz it