image: T4516: support for interoperability of legacy/new image tools

This commit allows management of system images with either new or legacy
tools: 'add/delete/rename system image' and 'set default' are translated
appropriately on booting between images with the old and new tools.
Consequently, the warning of the initial commit of T4516 is dropped.

(cherry picked from commit 96b65e90fbfa1fe63d97929ac86fc910abb0caa9)

1 files changed, 12 insertions, 5 deletions

diff --git a/src/op_mode/image_installer.py b/src/op_mode/image_installer.py
index 12d32968c..2d998f5e1 100755
--- a/src/op_mode/image_installer.py
+++ b/src/op_mode/image_installer.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright 2022 VyOS maintainers and contributors <maintainers@vyos.io>
+# Copyright 2023 VyOS maintainers and contributors <maintainers@vyos.io>
 #
 # This file is part of VyOS.
 #
@@ -28,7 +28,7 @@ from psutil import disk_partitions
 
 from vyos.configtree import ConfigTree
 from vyos.remote import download
-from vyos.system import disk, grub, image
+from vyos.system import disk, grub, image, compat, SYSTEM_CFG_VER
 from vyos.template import render
 from vyos.utils.io import ask_input, ask_yes_no
 from vyos.utils.file import chmod_2775
@@ -462,6 +462,7 @@ def install_image() -> None:
         exit(1)
 
 
+@compat.grub_cfg_update
 def add_image(image_path: str) -> None:
     """Add a new image
 
@@ -488,10 +489,16 @@ def add_image(image_path: str) -> None:
         Path(DIR_ROOTFS_SRC).mkdir(mode=0o755, parents=True)
         disk.partition_mount(f'{DIR_ISO_MOUNT}/live/filesystem.squashfs',
                              DIR_ROOTFS_SRC, 'squashfs')
-        version_file: str = Path(
-            f'{DIR_ROOTFS_SRC}/opt/vyatta/etc/version').read_text()
+
+        cfg_ver: str = image.get_image_tools_version(DIR_ROOTFS_SRC)
+        version_name: str = image.get_image_version(DIR_ROOTFS_SRC)
+
         disk.partition_umount(f'{DIR_ISO_MOUNT}/live/filesystem.squashfs')
-        version_name: str = version_file.lstrip('Version: ').strip()
+
+        if cfg_ver < SYSTEM_CFG_VER:
+            raise compat.DowngradingImageTools(
+                f'Adding image would downgrade image tools to v.{cfg_ver}; disallowed')
+
         image_name: str = ask_input(MSG_INPUT_IMAGE_NAME, version_name)
         set_as_default: bool = ask_yes_no(MSG_INPUT_IMAGE_DEFAULT, default=True)