Merge pull request rauc#726 from ejoerns/topic/install-hook-image

Support Omitting Filename When 'install' Slot Hook is Used

docs/using.rst

@@ -430,8 +430,9 @@ An example on how to use a post-install hook:
 
 The install hook will replace the entire default installation process for the
 target slot of the image it was specified for. Note that when having the install
-hook enabled, pre- and post-install hooks will *not* be executed.
-The install hook allows to fully customize the way an image is installed. This
+hook enabled, pre- and post-install hooks will *not* be executed and having
+an image (i.e. ``filename`` set) is optional, too!
+The install hook allows to fully customize the way a slot is updated. This
 allows performing special installation methods that are not natively supported
 by RAUC, for example to upgrade the bootloader to a new version while also
 migrating configuration settings.
@@ -447,6 +448,17 @@ migrating configuration settings.
   sha256=...
   hooks=install
 
+or, without ``filename``:
+
+.. code-block:: cfg
+
+  [hooks]
+  filename=hook
+
+  [image.datafs]
+  hooks=install
+
+
 Full Custom Update
 ~~~~~~~~~~~~~~~~~~
 

src/install.c

@@ -499,11 +499,11 @@ static void prepare_environment(GSubprocessLauncher *launcher, gchar *update_sou
 				RaucImage *img = l->data;
 				if (g_str_equal(slot->sclass, img->slotclass)) {
 					varname = g_strdup_printf("RAUC_IMAGE_NAME_%i", slotcnt);
-					g_subprocess_launcher_setenv(launcher, varname, img->filename, TRUE);
+					g_subprocess_launcher_setenv(launcher, varname, img->filename ?: "", TRUE);
 					g_clear_pointer(&varname, g_free);
 
 					varname = g_strdup_printf("RAUC_IMAGE_DIGEST_%i", slotcnt);
-					g_subprocess_launcher_setenv(launcher, varname, img->checksum.digest, TRUE);
+					g_subprocess_launcher_setenv(launcher, varname, img->checksum.digest ?: "", TRUE);
 					g_clear_pointer(&varname, g_free);
 
 					varname = g_strdup_printf("RAUC_IMAGE_CLASS_%i", slotcnt);
@@ -744,6 +744,10 @@ static gboolean pre_install_checks(gchar* bundledir, GList *install_images, GHas
 		RaucImage *mfimage = l->data;
 		RaucSlot *dest_slot = g_hash_table_lookup(target_group, mfimage->slotclass);
 
+		/* skip source image checks if filename is not set (install hook) */
+		if (!mfimage->filename && mfimage->hooks.install)
+			goto skip_filename_checks;
+
 		/* if image filename is relative, make it absolute */
 		if (!g_path_is_absolute(mfimage->filename)) {
 			gchar *filename = g_build_filename(bundledir, mfimage->filename, NULL);
@@ -757,6 +761,7 @@ static gboolean pre_install_checks(gchar* bundledir, GList *install_images, GHas
 			return FALSE;
 		}
 
+skip_filename_checks:
 		if (!g_file_test(dest_slot->device, G_FILE_TEST_EXISTS)) {
 			g_set_error(error, R_INSTALL_ERROR, R_INSTALL_ERROR_NODST,
 					"Destination device '%s' not found", dest_slot->device);
@@ -894,17 +899,19 @@ static gboolean launch_and_wait_default_handler(RaucInstallArgs *args, gchar* bu
 		g_free(slot_state->status);
 		slot_state->status = g_strdup("update");
 
-		g_message("Slot needs to be updated with %s", mfimage->filename);
-
 		r_context_end_step("check_slot", TRUE);
 
 		install_args_update(args, g_strdup_printf("Updating slot %s", dest_slot->name));
 
 		/* update slot */
-		if (mfimage->variant)
-			g_message("Updating %s with %s (variant: %s)", dest_slot->device, mfimage->filename, mfimage->variant);
-		else
-			g_message("Updating %s with %s", dest_slot->device, mfimage->filename);
+		if (mfimage->hooks.install) {
+			g_message("Updating %s with 'install' slot hook", dest_slot->device);
+		} else {
+			if (mfimage->variant)
+				g_message("Updating %s with %s (variant: %s)", dest_slot->device, mfimage->filename, mfimage->variant);
+			else
+				g_message("Updating %s with %s", dest_slot->device, mfimage->filename);
+		}
 
 		r_context_begin_step_formatted("copy_image", 0, "Copying image to %s", dest_slot->name);
 

src/main.c

@@ -658,6 +658,17 @@ static gboolean convert_start(int argc, char **argv)
 	return TRUE;
 }
 
+/* Definition list for terminal colors */
+#define KNRM  "\x1B[0m"
+#define KRED  "\x1B[31m"
+#define KGRN  "\x1B[32m"
+#define KYEL  "\x1B[33m"
+#define KBLU  "\x1B[34m"
+#define KMAG  "\x1B[35m"
+#define KCYN  "\x1B[36m"
+#define KWHT  "\x1B[37m"
+#define KBLD  "\x1B[1m"
+
 /* Takes a shell variable and its desired argument as input and appends it to
  * the provided text with taking care of correct shell quoting */
 static void formatter_shell_append(GString* text, const gchar* varname, const gchar* argument)
@@ -762,16 +773,20 @@ static gchar *info_formatter_readable(RaucManifest *manifest)
 	g_ptr_array_unref(hooks);
 
 	cnt = g_list_length(manifest->images);
-	g_string_append_printf(text, "%d Image%s%s\n", cnt, cnt == 1 ? "" : "s", cnt > 0 ? ":" : "");
+	g_string_append_printf(text, "\n%d Image%s%s\n", cnt, cnt == 1 ? "" : "s", cnt > 0 ? ":" : "");
 	cnt = 1;
 	for (GList *l = manifest->images; l != NULL; l = l->next) {
 		RaucImage *img = l->data;
-		g_string_append_printf(text, "(%d)\t%s\n", cnt, img->filename);
-		g_string_append_printf(text, "\tSlotclass: %s\n", img->slotclass);
+		g_string_append_printf(text, "  "KBLD "[%s]"KNRM "\n", img->slotclass);
 		if (img->variant)
 			g_string_append_printf(text, "\tVariant:   %s\n", img->variant);
-		g_string_append_printf(text, "\tChecksum:  %s\n", img->checksum.digest);
-		g_string_append_printf(text, "\tSize:      %"G_GOFFSET_FORMAT "\n", img->checksum.size);
+		if (img->filename) {
+			g_string_append_printf(text, "\tFilename:  %s\n", img->filename);
+			g_string_append_printf(text, "\tChecksum:  %s\n", img->checksum.digest);
+			g_string_append_printf(text, "\tSize:      %"G_GOFFSET_FORMAT "\n", img->checksum.size);
+		} else {
+			g_string_append_printf(text, "\t(no image file)\n");
+		}
 
 		hooks = g_ptr_array_new();
 		if (img->hooks.pre_install == TRUE) {
@@ -993,17 +1008,6 @@ static void free_status_print(RaucStatusPrint *status)
 
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(RaucStatusPrint, free_status_print);
 
-/* Definition list for terminal colors */
-#define KNRM  "\x1B[0m"
-#define KRED  "\x1B[31m"
-#define KGRN  "\x1B[32m"
-#define KYEL  "\x1B[33m"
-#define KBLU  "\x1B[34m"
-#define KMAG  "\x1B[35m"
-#define KCYN  "\x1B[36m"
-#define KWHT  "\x1B[37m"
-#define KBLD  "\x1B[1m"
-
 static void r_string_append_slot(GString *text, RaucSlot *slot, RaucStatusPrint *status)
 {
 	RaucSlotStatus *slot_state = slot->status;

src/manifest.c

@@ -45,14 +45,15 @@ static gboolean parse_image(GKeyFile *key_file, const gchar *group, RaucImage **
 		iimage->checksum.digest = value;
 	}
 	iimage->checksum.size = g_key_file_get_uint64(key_file,
-			group, "size", NULL);
-	g_key_file_remove_key(key_file, group, "size", NULL);
-
-	iimage->filename = key_file_consume_string(key_file, group, "filename", &ierror);
-	if (iimage->filename == NULL) {
+			group, "size", &ierror);
+	if (g_error_matches(ierror, G_KEY_FILE_ERROR, G_KEY_FILE_ERROR_KEY_NOT_FOUND)) {
+		iimage->checksum.size = -1;
+		g_clear_error(&ierror);
+	} else if (ierror) {
 		g_propagate_error(error, ierror);
 		goto out;
 	}
+	g_key_file_remove_key(key_file, group, "size", NULL);
 
 	hooks = g_key_file_get_string_list(key_file, group, "hooks", &entries, NULL);
 	for (gsize j = 0; j < entries; j++) {
@@ -70,6 +71,13 @@ static gboolean parse_image(GKeyFile *key_file, const gchar *group, RaucImage **
 	}
 	g_key_file_remove_key(key_file, group, "hooks", NULL);
 
+	iimage->filename = key_file_consume_string(key_file, group, "filename", &ierror);
+	/* 'filename' is optional only for 'install' hooks */
+	if (iimage->filename == NULL && !iimage->hooks.install) {
+		g_propagate_error(error, ierror);
+		goto out;
+	}
+
 	if (!check_remaining_keys(key_file, group, &ierror)) {
 		g_propagate_error(error, ierror);
 		goto out;
@@ -277,7 +285,12 @@ static gboolean check_manifest_common(const RaucManifest *mf, GError **error)
 		RaucImage *image = l->data;
 
 		g_assert(image);
-		g_assert(image->filename);
+
+		/* Having no 'filename' set is valid for 'install' hook only.
+		 * This is already ensured during manifest parsing, thus simply
+		 * skip further checks here */
+		if (!image->filename)
+			continue;
 
 		if (image->checksum.type != G_CHECKSUM_SHA256) {
 			g_set_error(error, R_MANIFEST_ERROR, R_MANIFEST_CHECK_ERROR, "Unsupported checksum algorithm for image %s", image->filename);
@@ -287,9 +300,19 @@ static gboolean check_manifest_common(const RaucManifest *mf, GError **error)
 			g_set_error(error, R_MANIFEST_ERROR, R_MANIFEST_CHECK_ERROR, "Missing digest for image %s", image->filename);
 			goto out;
 		}
-		if (!image->checksum.size) {
-			g_set_error(error, R_MANIFEST_ERROR, R_MANIFEST_CHECK_ERROR, "Missing size for image %s", image->filename);
-			goto out;
+		if (image->checksum.size < 0) {
+			/* RAUC versions before v1.5 allowed zero-size images but did not handle this explicitly.
+			 * Thus, bundles created did have a valid 'filename=' manifest entry
+			 * but the 'size=' entry was considered as empty and not set at all.
+			 * Retain support for this case, at least for the 'install' per-slot hook use-case
+			 * where an image file can be optional. */
+			if (image->hooks.install) {
+				g_message("Missing size parameter for image '%s'", image->filename);
+				image->checksum.size = 0;
+			} else {
+				g_set_error(error, R_MANIFEST_ERROR, R_MANIFEST_CHECK_ERROR, "Missing size for image %s", image->filename);
+				goto out;
+			}
 		}
 	}
 
@@ -507,7 +530,7 @@ static GKeyFile *prepare_manifest(const RaucManifest *mf)
 
 		if (image->checksum.type == G_CHECKSUM_SHA256)
 			g_key_file_set_string(key_file, group, "sha256", image->checksum.digest);
-		if (image->checksum.size)
+		if (image->checksum.size >= 0)
 			g_key_file_set_uint64(key_file, group, "size", image->checksum.size);
 
 		if (image->filename)
@@ -619,7 +642,15 @@ static gboolean update_manifest_checksums(RaucManifest *manifest, const gchar *d
 
 	for (GList *elem = manifest->images; elem != NULL; elem = elem->next) {
 		RaucImage *image = elem->data;
-		g_autofree gchar *filename = g_build_filename(dir, image->filename, NULL);
+		g_autofree gchar *filename = NULL;
+
+		/* If no filename is set (valid for 'install' hook) explicitly set size to -1 */
+		if (!image->filename) {
+			image->checksum.size = -1;
+			continue;
+		}
+
+		filename = g_build_filename(dir, image->filename, NULL);
 		res = compute_checksum(&image->checksum, filename, &ierror);
 		if (!res) {
 			g_warning("Failed updating checksum: %s", ierror->message);

src/update_handler.c

@@ -804,7 +804,7 @@ static gboolean run_slot_hook_extra_env(const gchar *hook_name, const gchar *hoo
 	g_assert_nonnull(slot->name);
 	g_assert_nonnull(slot->sclass);
 
-	g_message("Running slot hook %s for %s", hook_cmd, slot->name);
+	g_message("Running slot hook '%s' for %s", hook_cmd, slot->name);
 
 	launcher = g_subprocess_launcher_new(G_SUBPROCESS_FLAGS_NONE);
 
@@ -829,9 +829,9 @@ static gboolean run_slot_hook_extra_env(const gchar *hook_name, const gchar *hoo
 	}
 	if (image) {
 		image_size = g_strdup_printf("%" G_GOFFSET_FORMAT, image->checksum.size);
-		g_subprocess_launcher_setenv(launcher, "RAUC_IMAGE_NAME", image->filename, TRUE);
+		g_subprocess_launcher_setenv(launcher, "RAUC_IMAGE_NAME", image->filename ? image->filename : "", TRUE);
 		g_subprocess_launcher_setenv(launcher, "RAUC_IMAGE_SIZE", image_size, TRUE);
-		g_subprocess_launcher_setenv(launcher, "RAUC_IMAGE_DIGEST", image->checksum.digest, TRUE);
+		g_subprocess_launcher_setenv(launcher, "RAUC_IMAGE_DIGEST", image->checksum.digest ? image->checksum.digest : "", TRUE);
 		g_subprocess_launcher_setenv(launcher, "RAUC_IMAGE_CLASS", image->slotclass, TRUE);
 	}
 	g_subprocess_launcher_setenv(launcher, "RAUC_MOUNT_PREFIX", r_context()->config->mount_prefix, TRUE);
@@ -1866,7 +1866,6 @@ static gboolean hook_install_handler(RaucImage *image, RaucSlot *dest_slot, cons
 	gboolean res = FALSE;
 
 	/* run slot install hook */
-	g_message("Running custom slot install hook for %s", dest_slot->name);
 	res = run_slot_hook(hook_name, R_SLOT_HOOK_INSTALL, image, dest_slot, &ierror);
 	if (!res) {
 		g_propagate_error(error, ierror);

test/install-content/hook.sh

@@ -45,7 +45,7 @@ case "$1" in
 			test -n "$RAUC_SLOT_BOOTNAME" || die_error "missing RAUC_SLOT_BOOTNAME for $RAUC_SLOT_NAME"
 		fi
 
-		echo "RAUC_IMAGE_PATH: $RAUC_IMAGE_PATH"
+		echo "RAUC_IMAGE_NAME: $RAUC_IMAGE_NAME"
 		echo "RAUC_SLOT_DEVICE: $RAUC_SLOT_DEVICE"
 		echo "RAUC_SLOT_MOUNT_POINT: $RAUC_SLOT_MOUNT_POINT"
 		echo "RAUC_MOUNT_PREFIX: $RAUC_MOUNT_PREFIX"

test/install.c

@@ -106,6 +106,8 @@ filename=appfs.ext4";
 	fixture_helper_set_up_bundle(fixture->tmpdir, manifest_file, &data->manifest_test_options);
 }
 
+/* Note: Also ensures having no image in a slot with an 'install' per-slot hook
+ * is valid. */
 static void install_fixture_set_up_bundle_install_hook(InstallFixture *fixture,
 		gconstpointer user_data)
 {
@@ -122,7 +124,6 @@ filename=rootfs.ext4\n\
 hooks=install\n\
 \n\
 [image.appfs]\n\
-filename=appfs.ext4\n\
 hooks=install";
 
 	fixture->tmpdir = g_dir_make_tmp("rauc-XXXXXX", NULL);

test/manifest.c

@@ -353,6 +353,74 @@ hooks=install\n\
 	g_assert_false(res);
 }
 
+/* Check if missing 'size=' parameter in manifest image section causes and error.
+ * Also check that this does NOT cause an error when using a custom 'install'
+ * hook (to stay compatible with bundles having zero-size images generated with
+ * RAUC <1.5)
+ */
+static void test_manifest_missing_image_size(void)
+{
+	g_autofree gchar *tmpdir;
+	g_autofree gchar *manifestpath = NULL;
+	g_autoptr(RaucManifest) rm = NULL;
+	gboolean res = FALSE;
+	g_autoptr(GError) error = NULL;
+	const gchar *mffile_invalid = "\
+[update]\n\
+compatible=FooCorp Super BarBazzer\n\
+version=2015.04-1\n\
+\n\
+[hooks]\n\
+filename=demo.hook\n\
+\n\
+[image.rootfs]\n\
+filename=rootfs-default.ext4\n\
+sha256=0815\n\
+";
+	const gchar *mffile_valid = "\
+[update]\n\
+compatible=FooCorp Super BarBazzer\n\
+version=2015.04-1\n\
+\n\
+[hooks]\n\
+filename=demo.hook\n\
+\n\
+[image.rootfs]\n\
+filename=rootfs-default.ext4\n\
+sha256=0815\n\
+hooks=install\n\
+";
+
+	tmpdir = g_dir_make_tmp("rauc-XXXXXX", NULL);
+	g_assert_nonnull(tmpdir);
+
+	manifestpath = write_tmp_file(tmpdir, "invalid-manifest.raucm", mffile_invalid, NULL);
+	g_assert_nonnull(manifestpath);
+
+	res = load_manifest_file(manifestpath, &rm, &error);
+	g_assert_no_error(error);
+	g_assert_true(res);
+
+	res = check_manifest_internal(rm, &error);
+	g_assert_error(error, R_MANIFEST_ERROR, R_MANIFEST_CHECK_ERROR);
+	g_assert_false(res);
+
+	/* free */
+	g_free(manifestpath);
+	g_clear_pointer(&rm, free_manifest);
+	g_clear_error(&error);
+
+	manifestpath = write_tmp_file(tmpdir, "valid-manifest.raucm", mffile_valid, NULL);
+	g_assert_nonnull(manifestpath);
+
+	res = load_manifest_file(manifestpath, &rm, &error);
+	g_assert_no_error(error);
+	g_assert_true(res);
+
+	res = check_manifest_internal(rm, &error);
+	g_assert_no_error(error);
+	g_assert_true(res);
+}
 
 /* Test manifest/invalid_data:
  *
@@ -457,6 +525,7 @@ int main(int argc, char *argv[])
 	g_test_add_func("/manifest/load_variants", test_manifest_load_variants);
 	g_test_add_func("/manifest/invalid_hook_name", test_manifest_invalid_hook_name);
 	g_test_add_func("/manifest/missing_hook_name", test_manifest_missing_hook_name);
+	g_test_add_func("/manifest/missing_image_size", test_manifest_missing_image_size);
 	g_test_add_func("/manifest/invalid_data", test_invalid_data);
 
 	return g_test_run();