image: T4516: Added system image tools

This commit adds the whole set of system image tools written from the scratch in
Python that allows performing all the operations on images:

* check information
* perform installation and deletion
* versions management

Also, it contains a new service that will update the GRUB menu and keep tracking
its version in the future.

WARNING: The commit contains non-reversible changes. Because of boot menu
changes, it will not be possible to manage images from older VyOS versions after
an update.

5 files changed, 1080 insertions, 0 deletions

diff --git a/src/op_mode/image_info.py b/src/op_mode/image_info.py
new file mode 100644
index 000000000..ae0677196
--- /dev/null
+++ b/src/op_mode/image_info.py
@@ -0,0 +1,108 @@
+#!/usr/bin/env python3
+#
+# Copyright 2022 VyOS maintainers and contributors <maintainers@vyos.io>
+#
+# This file is part of VyOS.
+#
+# VyOS is free software: you can redistribute it and/or modify it under the
+# terms of the GNU General Public License as published by the Free Software
+# Foundation, either version 3 of the License, or (at your option) any later
+# version.
+#
+# VyOS is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+# details.
+#
+# You should have received a copy of the GNU General Public License along with
+# VyOS. If not, see <https://www.gnu.org/licenses/>.
+
+import sys
+from typing import List, Union
+
+from hurry.filesize import size
+from tabulate import tabulate
+
+from vyos import opmode
+from vyos.system import disk, grub, image
+
+
+def _format_show_images_summary(images_summary: image.BootDetails) -> str:
+    headers: list[str] = ['Name', 'Default boot', 'Running']
+    table_data: list[list[str]] = list()
+    for image_item in images_summary.get('images_available', []):
+        name: str = image_item
+        if images_summary.get('image_default') == name:
+            default: str = 'Yes'
+        else:
+            default: str = ''
+
+        if images_summary.get('image_running') == name:
+            running: str = 'Yes'
+        else:
+            running: str = ''
+
+        table_data.append([name, default, running])
+    tabulated: str = tabulate(table_data, headers)
+
+    return tabulated
+
+
+def _format_show_images_details(
+        images_details: list[image.ImageDetails]) -> str:
+    headers: list[str] = [
+        'Name', 'Version', 'Storage Read-Only', 'Storage Read-Write',
+        'Storage Total'
+    ]
+    table_data: list[list[Union[str, int]]] = list()
+    for image_item in images_details:
+        name: str = image_item.get('name')
+        version: str = image_item.get('version')
+        disk_ro: int = size(image_item.get('disk_ro'))
+        disk_rw: int = size(image_item.get('disk_rw'))
+        disk_total: int = size(image_item.get('disk_total'))
+        table_data.append([name, version, disk_ro, disk_rw, disk_total])
+    tabulated: str = tabulate(table_data, headers)
+
+    return tabulated
+
+
+def show_images_summary(raw: bool) -> Union[image.BootDetails, str]:
+    images_available: list[str] = grub.version_list()
+    root_dir: str = disk.find_persistence()
+    boot_vars: dict = grub.vars_read(f'{root_dir}/{image.CFG_VYOS_VARS}')
+
+    images_summary: image.BootDetails = dict()
+
+    images_summary['image_default'] = image.get_default_image()
+    images_summary['image_running'] = image.get_running_image()
+    images_summary['images_available'] = images_available
+    images_summary['console_type'] = boot_vars.get('console_type')
+    images_summary['console_num'] = boot_vars.get('console_num')
+
+    if raw:
+        return images_summary
+    else:
+        return _format_show_images_summary(images_summary)
+
+
+def show_images_details(raw: bool) -> Union[list[image.ImageDetails], str]:
+    images: list[str] = grub.version_list()
+    images_details: list[image.ImageDetails] = list()
+    for image_name in images:
+        images_details.append(image.get_details(image_name))
+
+    if raw:
+        return images_details
+    else:
+        return _format_show_images_details(images_details)
+
+
+if __name__ == '__main__':
+    try:
+        res = opmode.run(sys.modules[__name__])
+        if res:
+            print(res)
+    except (ValueError, opmode.Error) as e:
+        print(e)
+        sys.exit(1)
diff --git a/src/op_mode/image_installer.py b/src/op_mode/image_installer.py
new file mode 100644
index 000000000..6ebb38e46
--- /dev/null
+++ b/src/op_mode/image_installer.py
@@ -0,0 +1,557 @@
+#!/usr/bin/env python3
+#
+# Copyright 2022 VyOS maintainers and contributors <maintainers@vyos.io>
+#
+# This file is part of VyOS.
+#
+# VyOS is free software: you can redistribute it and/or modify it under the
+# terms of the GNU General Public License as published by the Free Software
+# Foundation, either version 3 of the License, or (at your option) any later
+# version.
+#
+# VyOS is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+# details.
+#
+# You should have received a copy of the GNU General Public License along with
+# VyOS. If not, see <https://www.gnu.org/licenses/>.
+
+from argparse import ArgumentParser, Namespace
+from pathlib import Path
+from shutil import copy, rmtree, copytree
+from sys import exit
+from urllib.parse import urlparse
+
+from psutil import disk_partitions
+
+from vyos.configtree import ConfigTree
+from vyos.remote import download
+from vyos.system import disk, grub, image
+from vyos.template import render
+from vyos.util import ask_input, ask_yes_no, run
+
+# define text messages
+MSG_ERR_NOT_LIVE: str = 'The system is already installed. Please use "add system image" instead.'
+MSG_ERR_LIVE: str = 'The system is in live-boot mode. Please use "install image" instead.'
+MSG_ERR_NO_DISK: str = 'No suitable disk was found. There must be at least one disk of 2GB or greater size.'
+MSG_INFO_INSTALL_WELCOME: str = 'Welcome to VyOS installation!\nThis command will install the VyOS to your permanent storage.'
+MSG_INFO_INSTALL_EXIT: str = 'Exitting from VyOS installation'
+MSG_INFO_INSTALL_SUCCESS: str = 'The image installed successfully'
+MSG_INFO_INSTALL_DISKS_LIST: str = 'Were found the next disks:'
+MSG_INFO_INSTALL_DISK_SELECT: str = 'Which one should be used for installation?'
+MSG_INFO_INSTALL_DISK_CONFIRM: str = 'Installation will delete all data on the drive. Continue?'
+MSG_INFO_INSTALL_PARTITONING: str = 'Creating partition table...'
+MSG_INPUT_CONFIG_FOUND: str = 'An active configuration was found. Would you like to copy it to the new image?'
+MSG_INPUT_IMAGE_NAME: str = 'What would you like to name this image?'
+MSG_INPUT_IMAGE_DEFAULT: str = 'Would you like to set a new image as default one for boot?'
+MSG_INPUT_PASSWORD: str = 'Please enter a password for the "vyos" user'
+MSG_INPUT_ROOT_SIZE_ALL: str = 'Would you like to use all free space on the drive?'
+MSG_INPUT_ROOT_SIZE_SET: str = 'What should be a size (in GB) of the root partition (min is 1.5 GB)?'
+MSG_INPUT_CONSOLE_TYPE: str = 'What console should be used by default? (K: KVM, S: Serial, U: USB-Serial)?'
+MSG_WARN_ISO_SIGN_INVALID: str = 'Signature is not valid. Do you want to continue with installation?'
+MSG_WARN_ISO_SIGN_UNAVAL: str = 'Signature is not available. Do you want to continue with installation?'
+MSG_WARN_ROOT_SIZE_TOOBIG: str = 'The size is too big. Try again.'
+MSG_WARN_ROOT_SIZE_TOOSMALL: str = 'The size is too small. Try again'
+MSG_WARN_IMAGE_NAME_WRONG: str = 'The suggested name is unsupported!\n'
+'It must be between 1 and 32 characters long and contains only the next characters: .+-_ a-z A-Z 0-9'
+CONST_MIN_DISK_SIZE: int = 2147483648  # 2 GB
+CONST_MIN_ROOT_SIZE: int = 1610612736  # 1.5 GB
+# a reserved space: 2MB for header, 1 MB for BIOS partition, 256 MB for EFI
+CONST_RESERVED_SPACE: int = (2 + 1 + 256) * 1024**2
+
+# define directories and paths
+DIR_INSTALLATION: str = '/mnt/installation'
+DIR_ROOTFS_SRC: str = f'{DIR_INSTALLATION}/root_src'
+DIR_ROOTFS_DST: str = f'{DIR_INSTALLATION}/root_dst'
+DIR_ISO_MOUNT: str = f'{DIR_INSTALLATION}/iso_src'
+DIR_DST_ROOT: str = f'{DIR_INSTALLATION}/disk_dst'
+DIR_KERNEL_SRC: str = '/boot/'
+FILE_ROOTFS_SRC: str = '/usr/lib/live/mount/medium/live/filesystem.squashfs'
+ISO_DOWNLOAD_PATH: str = '/tmp/vyos_installation.iso'
+
+# default boot variables
+DEFAULT_BOOT_VARS: dict[str, str] = {
+    'timeout': '5',
+    'console_type': 'tty',
+    'console_num': '0',
+    'bootmode': 'normal'
+}
+
+
+def bytes_to_gb(size: int) -> float:
+    """Convert Bytes to GBytes, rounded to 1 decimal number
+
+    Args:
+        size (int): input size in bytes
+
+    Returns:
+        float: size in GB
+    """
+    return round(size / 1024**3, 1)
+
+
+def gb_to_bytes(size: float) -> int:
+    """Convert GBytes to Bytes
+
+    Args:
+        size (float): input size in GBytes
+
+    Returns:
+        int: size in bytes
+    """
+    return int(size * 1024**3)
+
+
+def find_disk() -> tuple[str, int]:
+    """Find a target disk for installation
+
+    Returns:
+        tuple[str, int]: disk name and size in bytes
+    """
+    # check for available disks
+    disks_available: dict[str, int] = disk.disks_size()
+    for disk_name, disk_size in disks_available.copy().items():
+        if disk_size < CONST_MIN_DISK_SIZE:
+            del disks_available[disk_name]
+    if not disks_available:
+        print(MSG_ERR_NO_DISK)
+        exit(MSG_INFO_INSTALL_EXIT)
+
+    # select one as a target
+    print(MSG_INFO_INSTALL_DISKS_LIST)
+    default_disk: str = list(disks_available)[0]
+    for disk_name, disk_size in disks_available.items():
+        disk_size_human: str = bytes_to_gb(disk_size)
+        print(f'Drive: {disk_name} ({disk_size_human} GB)')
+    disk_selected: str = ask_input(MSG_INFO_INSTALL_DISK_SELECT,
+                                   default=default_disk,
+                                   valid_responses=list(disks_available))
+
+    return disk_selected, disks_available[disk_selected]
+
+
+def ask_root_size(available_space: int) -> int:
+    """Define a size of root partition
+
+    Args:
+        available_space (int): available space in bytes for a root partition
+
+    Returns:
+        int: defined size
+    """
+    if ask_yes_no(MSG_INPUT_ROOT_SIZE_ALL, default=True):
+        return available_space
+
+    while True:
+        root_size_gb: str = ask_input(MSG_INPUT_ROOT_SIZE_SET)
+        root_size_kbytes: int = (gb_to_bytes(float(root_size_gb))) // 1024
+
+        if root_size_kbytes > available_space:
+            print(MSG_WARN_ROOT_SIZE_TOOBIG)
+            continue
+        if root_size_kbytes < CONST_MIN_ROOT_SIZE / 1024:
+            print(MSG_WARN_ROOT_SIZE_TOOSMALL)
+            continue
+
+        return root_size_kbytes
+
+
+def prepare_tmp_disr() -> None:
+    """Create temporary directories for installation
+    """
+    print('Creating temporary directories')
+    for dir in [DIR_ROOTFS_SRC, DIR_ROOTFS_DST, DIR_DST_ROOT]:
+        dirpath = Path(dir)
+        dirpath.mkdir(mode=0o755, parents=True)
+
+
+def setup_grub(root_dir: str) -> None:
+    """Install GRUB configurations
+
+    Args:
+        root_dir (str): a path to the root of target filesystem
+    """
+    print('Installing GRUB configuration files')
+    grub_cfg_main = f'{root_dir}/{grub.GRUB_DIR_MAIN}/grub.cfg'
+    grub_cfg_vars = f'{root_dir}/{grub.CFG_VYOS_VARS}'
+    grub_cfg_modules = f'{root_dir}/{grub.CFG_VYOS_MODULES}'
+    grub_cfg_menu = f'{root_dir}/{grub.CFG_VYOS_MENU}'
+    grub_cfg_options = f'{root_dir}/{grub.CFG_VYOS_OPTIONS}'
+
+    # create new files
+    render(grub_cfg_main, grub.TMPL_GRUB_MAIN, {})
+    grub.common_write(root_dir)
+    grub.vars_write(grub_cfg_vars, DEFAULT_BOOT_VARS)
+    grub.modules_write(grub_cfg_modules, [])
+    grub.write_cfg_ver(1, root_dir)
+    render(grub_cfg_menu, grub.TMPL_GRUB_MENU, {})
+    render(grub_cfg_options, grub.TMPL_GRUB_OPTS, {})
+
+
+def configure_authentication(config_file: str, password: str) -> None:
+    config = ConfigTree(config_file)
+    config.set([
+        'system', 'login', 'user', 'vyos', 'authentication',
+        'plaintext-password'
+    ],
+               value=password,
+               replace=True)
+    config.set_tag(['system', 'login', 'user'])
+
+
+def validate_signature(file_path: str, sign_type: str) -> None:
+    """Validate a file by signature and delete a signature file
+
+    Args:
+        file_path (str): a path to file
+        sign_type (str): a signature type
+    """
+    print('Validating signature')
+    signature_valid: bool = False
+    # validate with minisig
+    if sign_type == 'minisig':
+        for pubkey in [
+                '/usr/share/vyos/keys/vyos-release.minisign.pub',
+                '/usr/share/vyos/keys/vyos-backup.minisign.pub'
+        ]:
+            if run(f'minisign -V -q -p {pubkey} -m {file_path} -x {file_path}.minisig'
+                  ) == 0:
+                signature_valid = True
+                break
+        Path(f'{file_path}.minisig').unlink()
+    # validate with GPG
+    if sign_type == 'asc':
+        if run(f'gpg --verify ${file_path}.asc ${file_path}') == 0:
+            signature_valid = True
+        Path(f'{file_path}.asc').unlink()
+
+    # warn or pass
+    if not signature_valid:
+        if not ask_yes_no(MSG_WARN_ISO_SIGN_INVALID, default=False):
+            exit(MSG_INFO_INSTALL_EXIT)
+    else:
+        print('Signature is valid')
+
+
+def image_fetch(image_path: str) -> Path:
+    """Fetch an ISO image
+
+    Args:
+        image_path (str): a path, remote or local
+
+    Returns:
+        Path: a path to a local file
+    """
+    try:
+        # check a type of path
+        if urlparse(image_path).scheme:
+            # download an image
+            download(ISO_DOWNLOAD_PATH, image_path, True, True)
+            # download a signature
+            sign_file = (False, '')
+            for sign_type in ['minisig', 'asc']:
+                try:
+                    download(f'{ISO_DOWNLOAD_PATH}.{sign_type}',
+                             f'{image_path}.{sign_type}')
+                    sign_file = (True, sign_type)
+                    break
+                except Exception:
+                    print(f'{sign_type} signature is not available')
+            # validate a signature if it is available
+            if sign_file[0]:
+                validate_signature(ISO_DOWNLOAD_PATH, sign_file[1])
+            else:
+                if not ask_yes_no(MSG_WARN_ISO_SIGN_UNAVAL, default=False):
+                    cleanup()
+                    exit(MSG_INFO_INSTALL_EXIT)
+
+            return Path(ISO_DOWNLOAD_PATH)
+        else:
+            local_path: Path = Path(image_path)
+            if local_path.is_file():
+                return local_path
+            else:
+                raise
+    except Exception:
+        print(f'The image cannot be fetched from: {image_path}')
+        exit(1)
+
+
+def migrate_config() -> bool:
+    """Check for active config and ask user for migration
+
+    Returns:
+        bool: user's decision
+    """
+    active_config_path: Path = Path('/opt/vyatta/etc/config/config.boot')
+    if active_config_path.exists():
+        if ask_yes_no(MSG_INPUT_CONFIG_FOUND, default=True):
+            return True
+    return False
+
+
+def cleanup(mounts: list[str] = [], remove_items: list[str] = []) -> None:
+    """Clean up after installation
+
+    Args:
+        mounts (list[str], optional): List of mounts to unmount.
+        Defaults to [].
+        remove_items (list[str], optional): List of files or directories
+        to remove. Defaults to [].
+    """
+    print('Cleaning up')
+    # clean up installation directory by default
+    mounts_all = disk_partitions(all=True)
+    for mounted_device in mounts_all:
+        if mounted_device.mountpoint.startswith(DIR_INSTALLATION) and not (
+                mounted_device.device in mounts or
+                mounted_device.mountpoint in mounts):
+            mounts.append(mounted_device.mountpoint)
+    # add installation dir to cleanup list
+    if DIR_INSTALLATION not in remove_items:
+        remove_items.append(DIR_INSTALLATION)
+    # also delete an ISO file
+    if Path(ISO_DOWNLOAD_PATH).exists(
+    ) and ISO_DOWNLOAD_PATH not in remove_items:
+        remove_items.append(ISO_DOWNLOAD_PATH)
+
+    if mounts:
+        print('Unmounting target filesystems')
+        for mountpoint in mounts:
+            disk.partition_umount(mountpoint)
+    if remove_items:
+        print('Removing temporary files')
+        for remove_item in remove_items:
+            if Path(remove_item).exists():
+                if Path(remove_item).is_file():
+                    Path(remove_item).unlink()
+                if Path(remove_item).is_dir():
+                    rmtree(remove_item)
+
+
+def install_image() -> None:
+    """Install an image to a disk
+    """
+    if not image.is_live_boot():
+        exit(MSG_ERR_NOT_LIVE)
+
+    print(MSG_INFO_INSTALL_WELCOME)
+    if not ask_yes_no('Would you like to continue?'):
+        print(MSG_INFO_INSTALL_EXIT)
+        exit()
+
+    try:
+        # configure image name
+        running_image_name: str = image.get_running_image()
+        while True:
+            image_name: str = ask_input(MSG_INPUT_IMAGE_NAME,
+                                        running_image_name)
+            if image.validate_name(image_name):
+                break
+            print(MSG_WARN_IMAGE_NAME_WRONG)
+
+        # define target drive
+        install_target, target_size = find_disk()
+
+        # define target rootfs size in KB (smallest unit acceptable by sgdisk)
+        availabe_size: int = (target_size - CONST_RESERVED_SPACE) // 1024
+        rootfs_size: int = ask_root_size(availabe_size)
+
+        # ask for password
+        user_password: str = ask_input(MSG_INPUT_PASSWORD, default='vyos')
+
+        # ask for default console
+        console_type: str = ask_input(MSG_INPUT_CONSOLE_TYPE,
+                                      default='K',
+                                      valid_responses=['K', 'S', 'U'])
+        console_dict: dict[str, str] = {'K': 'tty', 'S': 'ttyS', 'U': 'ttyUSB'}
+
+        # create partitions
+        if not ask_yes_no(MSG_INFO_INSTALL_DISK_CONFIRM):
+            print(MSG_INFO_INSTALL_EXIT)
+            exit()
+        print(MSG_INFO_INSTALL_PARTITONING)
+        disk.disk_cleanup(install_target)
+        disk.parttable_create(install_target, rootfs_size)
+        disk.filesystem_create(f'{install_target}2', 'efi')
+        disk.filesystem_create(f'{install_target}3', 'ext4')
+
+        # create directiroes for installation media
+        prepare_tmp_disr()
+
+        # mount target filesystem and create required dirs inside
+        print('Mounting new partitions')
+        disk.partition_mount(f'{install_target}3', DIR_DST_ROOT)
+        Path(f'{DIR_DST_ROOT}/boot/efi').mkdir(parents=True)
+        disk.partition_mount(f'{install_target}2', f'{DIR_DST_ROOT}/boot/efi')
+
+        # a config dir. It is the deepest one, so the comand will
+        # create all the rest in a single step
+        print('Creating a configuration file')
+        target_config_dir: str = f'{DIR_DST_ROOT}/boot/{image_name}/rw/opt/vyatta/etc/config/'
+        Path(target_config_dir).mkdir(parents=True)
+        # copy config
+        if migrate_config():
+            copy('/opt/vyatta/etc/config/config.boot', target_config_dir)
+        else:
+            copy('/opt/vyatta/etc/config.boot.default',
+                 f'{target_config_dir}/config.boot')
+        configure_authentication(f'{target_config_dir}/config.boot',
+                                 user_password)
+        Path(f'{target_config_dir}/.vyatta_config').touch()
+
+        # create a persistence.conf
+        Path(f'{DIR_DST_ROOT}/persistence.conf').write_text('/ union\n')
+
+        # copy system image and kernel files
+        print('Copying system image files')
+        for file in Path(DIR_KERNEL_SRC).iterdir():
+            if file.is_file():
+                copy(file, f'{DIR_DST_ROOT}/boot/{image_name}/')
+        copy(FILE_ROOTFS_SRC,
+             f'{DIR_DST_ROOT}/boot/{image_name}/{image_name}.squashfs')
+
+        # install GRUB
+        print('Installing GRUB to the drive')
+        grub.install(install_target, f'{DIR_DST_ROOT}/boot/',
+                     f'{DIR_DST_ROOT}/boot/efi')
+        setup_grub(DIR_DST_ROOT)
+        # add information about version
+        grub.create_structure()
+        grub.version_add(image_name, DIR_DST_ROOT)
+        grub.set_default(image_name, DIR_DST_ROOT)
+        grub.set_console_type(console_dict[console_type], DIR_DST_ROOT)
+
+        # umount filesystems and remove temporary files
+        cleanup([f'{install_target}2', f'{install_target}3'],
+                ['/mnt/installation'])
+
+        # we are done
+        print(MSG_INFO_INSTALL_SUCCESS)
+        exit()
+
+    except Exception as err:
+        print(f'Unable to install VyOS: {err}')
+        # unmount filesystems and clenup
+        try:
+            cleanup([f'{install_target}2', f'{install_target}3'],
+                    ['/mnt/installation'])
+        except Exception as err:
+            print(f'Cleanup failed: {err}')
+
+        exit(1)
+
+
+def add_image(image_path: str) -> None:
+    """Add a new image
+
+    Args:
+        image_path (str): a path to an ISO image
+    """
+    if image.is_live_boot():
+        exit(MSG_ERR_LIVE)
+
+    # fetch an image
+    iso_path: Path = image_fetch(image_path)
+    try:
+        # mount an ISO
+        Path(DIR_ISO_MOUNT).mkdir(mode=0o755, parents=True)
+        disk.partition_mount(iso_path, DIR_ISO_MOUNT, 'iso9660')
+
+        # check sums
+        print('Validating image checksums')
+        if run(f'cd {DIR_ISO_MOUNT} && sha256sum --status -c sha256sum.txt'):
+            cleanup()
+            exit('Image checksum verification failed.')
+
+        # mount rootfs (to get a system version)
+        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()
+        disk.partition_umount(f'{DIR_ISO_MOUNT}/live/filesystem.squashfs')
+        version_name: str = version_file.lstrip('Version: ').strip()
+        image_name: str = ask_input(MSG_INPUT_IMAGE_NAME, version_name)
+        set_as_default: bool = ask_yes_no(MSG_INPUT_IMAGE_DEFAULT, default=True)
+
+        # find target directory
+        root_dir: str = disk.find_persistence()
+
+        # a config dir. It is the deepest one, so the comand will
+        # create all the rest in a single step
+        target_config_dir: str = f'{root_dir}/boot/{image_name}/rw/opt/vyatta/etc/config/'
+        # copy config
+        if migrate_config():
+            print('Copying configuration directory')
+            copytree('/opt/vyatta/etc/config/', target_config_dir)
+        else:
+            Path(target_config_dir).mkdir(parents=True)
+            Path(f'{target_config_dir}/.vyatta_config').touch()
+
+        # copy system image and kernel files
+        print('Copying system image files')
+        for file in Path(f'{DIR_ISO_MOUNT}/live').iterdir():
+            if file.is_file() and (file.match('initrd*') or
+                                   file.match('vmlinuz*')):
+                copy(file, f'{root_dir}/boot/{image_name}/')
+        copy(f'{DIR_ISO_MOUNT}/live/filesystem.squashfs',
+             f'{root_dir}/boot/{image_name}/{image_name}.squashfs')
+
+        # unmount an ISO and cleanup
+        cleanup([str(iso_path)])
+
+        # add information about version
+        grub.version_add(image_name, root_dir)
+        if set_as_default:
+            grub.set_default(image_name, root_dir)
+
+    except Exception as err:
+        # unmount an ISO and cleanup
+        cleanup([str(iso_path)])
+        exit(f'Whooops: {err}')
+
+
+def parse_arguments() -> Namespace:
+    """Parse arguments
+
+    Returns:
+        Namespace: a namespace with parsed arguments
+    """
+    parser: ArgumentParser = ArgumentParser(
+        description='Install new system images')
+    parser.add_argument('--action',
+                        choices=['install', 'add'],
+                        required=True,
+                        help='action to perform with an image')
+    parser.add_argument(
+        '--image_path',
+        help='a path (HTTP or local file) to an image that needs to be installed'
+    )
+    # parser.add_argument('--image_new_name', help='a new name for image')
+    args: Namespace = parser.parse_args()
+    # Validate arguments
+    if args.action == 'add' and not args.image_path:
+        exit('A path to image is required for add action')
+
+    return args
+
+
+if __name__ == '__main__':
+    try:
+        args: Namespace = parse_arguments()
+        if args.action == 'install':
+            install_image()
+        if args.action == 'add':
+            add_image(args.image_path)
+
+        exit()
+
+    except KeyboardInterrupt:
+        print('Stopped by Ctrl+C')
+        cleanup()
+        exit()
+
+    except Exception as err:
+        exit(f'{err}')
diff --git a/src/op_mode/image_manager.py b/src/op_mode/image_manager.py
new file mode 100644
index 000000000..ac889da38
--- /dev/null
+++ b/src/op_mode/image_manager.py
@@ -0,0 +1,190 @@
+#!/usr/bin/env python3
+#
+# Copyright 2022 VyOS maintainers and contributors <maintainers@vyos.io>
+#
+# This file is part of VyOS.
+#
+# VyOS is free software: you can redistribute it and/or modify it under the
+# terms of the GNU General Public License as published by the Free Software
+# Foundation, either version 3 of the License, or (at your option) any later
+# version.
+#
+# VyOS is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+# details.
+#
+# You should have received a copy of the GNU General Public License along with
+# VyOS. If not, see <https://www.gnu.org/licenses/>.
+
+from argparse import ArgumentParser, Namespace
+from pathlib import Path
+from shutil import rmtree
+from sys import exit
+
+from vyos.system import disk, grub, image
+from vyos.util import ask_yes_no
+
+
+def delete_image(image_name: str) -> None:
+    """Remove installed image files and boot entry
+
+    Args:
+        image_name (str): a name of image to delete
+    """
+    if image_name == image.get_running_image():
+        exit('Currently running image cannot be deleted')
+    if image_name == image.get_default_image():
+        exit('Default image cannot be deleted')
+    available_images: list[str] = grub.version_list()
+    if image_name not in available_images:
+        exit(f'The image "{image_name}" cannot be found')
+    presistence_storage: str = disk.find_persistence()
+    if not presistence_storage:
+        exit('Persistence storage cannot be found')
+
+    if not ask_yes_no(f'Do you really want to delete the image {image_name}?',
+                      default=False):
+        exit()
+
+    # remove files and menu entry
+    version_path: Path = Path(f'{presistence_storage}/boot/{image_name}')
+    try:
+        rmtree(version_path)
+        grub.version_del(image_name, presistence_storage)
+        print(f'The image "{image_name}" was successfully deleted')
+    except Exception as err:
+        exit(f'Unable to remove the image "{image_name}": {err}')
+
+
+def set_image(image_name: str) -> None:
+    """Set default boot image
+
+    Args:
+        image_name (str): an image name
+    """
+    if image_name == image.get_default_image():
+        exit(f'The image "{image_name}" already configured as default')
+    available_images: list[str] = grub.version_list()
+    if image_name not in available_images:
+        exit(f'The image "{image_name}" cannot be found')
+    presistence_storage: str = disk.find_persistence()
+    if not presistence_storage:
+        exit('Persistence storage cannot be found')
+
+    if not ask_yes_no(
+            f'Do you really want to set the image {image_name} '
+            'as default boot image?',
+            default=False):
+        exit()
+
+    # set default boot image
+    try:
+        grub.set_default(image_name, presistence_storage)
+        print(f'The image "{image_name}" is now default boot image')
+    except Exception as err:
+        exit(f'Unable to set default image "{image_name}": {err}')
+
+
+def rename_image(name_old: str, name_new: str) -> None:
+    """Rename installed image
+
+    Args:
+        name_old (str): old name
+        name_new (str): new name
+    """
+    if name_old == image.get_running_image():
+        exit('Currently running image cannot be renamed')
+    available_images: list[str] = grub.version_list()
+    if name_old not in available_images:
+        exit(f'The image "{name_old}" cannot be found')
+    if name_new in available_images:
+        exit(f'The image "{name_new}" already exists')
+    if not image.validate_name(name_new):
+        exit(f'The image name "{name_new}" is not allowed')
+
+    presistence_storage: str = disk.find_persistence()
+    if not presistence_storage:
+        exit('Persistence storage cannot be found')
+
+    if not ask_yes_no(
+            f'Do you really want to rename the image {name_old} '
+            f'to the {name_new}?',
+            default=False):
+        exit()
+
+    try:
+        # replace default boot item
+        if name_old == image.get_default_image():
+            grub.set_default(name_new, presistence_storage)
+
+        # rename files and dirs
+        old_path: Path = Path(f'{presistence_storage}/boot/{name_old}')
+        new_path: Path = Path(f'{presistence_storage}/boot/{name_new}')
+        old_path.rename(new_path)
+
+        # replace boot item
+        grub.version_del(name_old, presistence_storage)
+        grub.version_add(name_new, presistence_storage)
+
+        print(f'The image "{name_old}" was renamed to "{name_new}"')
+    except Exception as err:
+        exit(f'Unable to rename image "{name_old}" to "{name_new}": {err}')
+
+
+def list_images() -> None:
+    """Print list of available images for CLI hints"""
+    images_list: list[str] = grub.version_list()
+    for image_name in images_list:
+        print(image_name)
+
+
+def parse_arguments() -> Namespace:
+    """Parse arguments
+
+    Returns:
+        Namespace: a namespace with parsed arguments
+    """
+    parser: ArgumentParser = ArgumentParser(description='Manage system images')
+    parser.add_argument('--action',
+                        choices=['delete', 'set', 'rename', 'list'],
+                        required=True,
+                        help='action to perform with an image')
+    parser.add_argument(
+        '--image_name',
+        help=
+        'a name of an image to add, delete, install, rename, or set as default')
+    parser.add_argument('--image_new_name', help='a new name for image')
+    args: Namespace = parser.parse_args()
+    # Validate arguments
+    if args.action == 'delete' and not args.image_name:
+        exit('An image name is required for delete action')
+    if args.action == 'set' and not args.image_name:
+        exit('An image name is required for set action')
+    if args.action == 'rename' and (not args.image_name or
+                                    not args.image_new_name):
+        exit('Both old and new image names are required for rename action')
+
+    return args
+
+
+if __name__ == '__main__':
+    try:
+        args: Namespace = parse_arguments()
+        if args.action == 'delete':
+            delete_image(args.image_name)
+        if args.action == 'set':
+            set_image(args.image_name)
+        if args.action == 'rename':
+            rename_image(args.image_name, args.image_new_name)
+        if args.action == 'list':
+            list_images()
+
+        exit()
+
+    except KeyboardInterrupt:
+        print('Stopped by Ctrl+C')
+        exit()
+
+    except Exception as err:
+        exit(f'{err}')
diff --git a/src/system/grub_update.py b/src/system/grub_update.py
new file mode 100644
index 000000000..ebdc73af0
--- /dev/null
+++ b/src/system/grub_update.py
@@ -0,0 +1,211 @@
+#!/usr/bin/env python3
+#
+# Copyright 2022 VyOS maintainers and contributors <maintainers@vyos.io>
+#
+# This file is part of VyOS.
+#
+# VyOS is free software: you can redistribute it and/or modify it under the
+# terms of the GNU General Public License as published by the Free Software
+# Foundation, either version 3 of the License, or (at your option) any later
+# version.
+#
+# VyOS is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+# details.
+#
+# You should have received a copy of the GNU General Public License along with
+# VyOS. If not, see <https://www.gnu.org/licenses/>.
+
+from pathlib import Path
+from re import compile, MULTILINE, DOTALL
+from sys import exit
+
+from vyos.system import disk, grub, image
+from vyos.template import render
+
+# define configuration version
+CFG_VER = 1
+
+# define regexes and variables
+REGEX_VERSION = r'^menuentry "[^\n]*{\n[^}]*\s+linux /boot/(?P<version>\S+)/[^}]*}'
+REGEX_MENUENTRY = r'^menuentry "[^\n]*{\n[^}]*\s+linux /boot/(?P<version>\S+)/vmlinuz (?P<options>[^\n]+)\n[^}]*}'
+REGEX_CONSOLE = r'^.*console=(?P<console_type>[^\s\d]+)(?P<console_num>[\d]+).*$'
+REGEX_SANIT_CONSOLE = r'\ ?console=[^\s\d]+[\d]+(,\d+)?\ ?'
+REGEX_SANIT_INIT = r'\ ?init=\S*\ ?'
+PW_RESET_OPTION = 'init=/opt/vyatta/sbin/standalone_root_pw_reset'
+
+
+def cfg_check_update() -> bool:
+    """Check if GRUB structure update is required
+
+    Returns:
+        bool: False if not required, True if required
+    """
+    current_ver = grub.get_cfg_ver()
+    if current_ver and current_ver >= CFG_VER:
+        return False
+    else:
+        return True
+
+
+def find_versions(menu_entries: list) -> list:
+    """Find unique VyOS versions from menu entries
+
+    Args:
+        menu_entries (list): a list with menu entries
+
+    Returns:
+        list: List of installed versions
+    """
+    versions = []
+    for vyos_ver in menu_entries:
+        versions.append(vyos_ver.get('version'))
+    # remove duplicates
+    versions = list(set(versions))
+    return versions
+
+
+def filter_unparsed(grub_path: str) -> str:
+    """Find currently installed VyOS version
+
+    Args:
+        grub_path (str): a path to the grub.cfg file
+
+    Returns:
+        str: unparsed grub.cfg items
+    """
+    config_text = Path(grub_path).read_text()
+    regex_filter = compile(REGEX_VERSION, MULTILINE | DOTALL)
+    filtered = regex_filter.sub('', config_text)
+    regex_filter = compile(grub.REGEX_GRUB_VARS, MULTILINE)
+    filtered = regex_filter.sub('', filtered)
+    regex_filter = compile(grub.REGEX_GRUB_MODULES, MULTILINE)
+    filtered = regex_filter.sub('', filtered)
+    # strip extra new lines
+    filtered = filtered.strip()
+    return filtered
+
+
+def sanitize_boot_opts(boot_opts: str) -> str:
+    """Sanitize boot options from console and init
+
+    Args:
+        boot_opts (str): boot options
+
+    Returns:
+        str: sanitized boot options
+    """
+    regex_filter = compile(REGEX_SANIT_CONSOLE)
+    boot_opts = regex_filter.sub('', boot_opts)
+    regex_filter = compile(REGEX_SANIT_INIT)
+    boot_opts = regex_filter.sub('', boot_opts)
+
+    return boot_opts
+
+
+def parse_entry(entry: tuple) -> dict:
+    """Parse GRUB menuentry
+
+    Args:
+        entry (tuple): tuple of (version, options)
+
+    Returns:
+        dict: dictionary with parsed options
+    """
+    # save version to dict
+    entry_dict = {'version': entry[0]}
+    # detect boot mode type
+    if PW_RESET_OPTION in entry[1]:
+        entry_dict['bootmode'] = 'pw_reset'
+    else:
+        entry_dict['bootmode'] = 'normal'
+    # find console type and number
+    regex_filter = compile(REGEX_CONSOLE)
+    entry_dict.update(regex_filter.match(entry[1]).groupdict())
+    entry_dict['boot_opts'] = sanitize_boot_opts(entry[1])
+
+    return entry_dict
+
+
+def parse_menuntries(grub_path: str) -> list:
+    """Parse all GRUB menuentries
+
+    Args:
+        grub_path (str): a path to GRUB config file
+
+    Returns:
+        list: list with menu items (each item is a dict)
+    """
+    menuentries = []
+    # read configuration file
+    config_text = Path(grub_path).read_text()
+    # parse menuentries to tuples (version, options)
+    regex_filter = compile(REGEX_MENUENTRY, MULTILINE)
+    filter_results = regex_filter.findall(config_text)
+    # parse each entry
+    for entry in filter_results:
+        menuentries.append(parse_entry(entry))
+
+    return menuentries
+
+
+if __name__ == '__main__':
+    # Skip everything if update is not required
+    if not cfg_check_update():
+        exit(0)
+
+    # find root directory of persistent storage
+    root_dir = disk.find_persistence()
+
+    # read current GRUB config
+    grub_cfg_main = f'{root_dir}/{image.GRUB_DIR_MAIN}/grub.cfg'
+    vars = grub.vars_read(grub_cfg_main)
+    modules = grub.modules_read(grub_cfg_main)
+    vyos_menuentries = parse_menuntries(grub_cfg_main)
+    vyos_versions = find_versions(vyos_menuentries)
+    unparsed_items = filter_unparsed(grub_cfg_main)
+
+    # find default values
+    default_entry = vyos_menuentries[int(vars['default'])]
+    default_settings = {
+        'default': grub.gen_version_uuid(default_entry['version']),
+        'bootmode': default_entry['bootmode'],
+        'console_type': default_entry['console_type'],
+        'console_num': default_entry['console_num']
+    }
+    vars.update(default_settings)
+
+    # print(f'vars: {vars}')
+    # print(f'modules: {modules}')
+    # print(f'vyos_menuentries: {vyos_menuentries}')
+    # print(f'unparsed_items: {unparsed_items}')
+
+    # create new files
+    grub_cfg_vars = f'{root_dir}/{image.CFG_VYOS_VARS}'
+    grub_cfg_modules = f'{root_dir}/{grub.CFG_VYOS_MODULES}'
+    grub_cfg_platform = f'{root_dir}/{grub.CFG_VYOS_PLATFORM}'
+    grub_cfg_menu = f'{root_dir}/{grub.CFG_VYOS_MENU}'
+    grub_cfg_options = f'{root_dir}/{grub.CFG_VYOS_OPTIONS}'
+
+    render(grub_cfg_main, grub.TMPL_GRUB_MAIN, {})
+    Path(image.GRUB_DIR_VYOS).mkdir(exist_ok=True)
+    grub.vars_write(grub_cfg_vars, vars)
+    grub.modules_write(grub_cfg_modules, modules)
+    # Path(grub_cfg_platform).write_text(unparsed_items)
+    grub.common_write()
+    render(grub_cfg_menu, grub.TMPL_GRUB_MENU, {})
+    render(grub_cfg_options, grub.TMPL_GRUB_OPTS, {})
+
+    # create menu entries
+    for vyos_ver in vyos_versions:
+        boot_opts = None
+        for entry in vyos_menuentries:
+            if entry.get('version') == vyos_ver and entry.get(
+                    'bootmode') == 'normal':
+                boot_opts = entry.get('boot_opts')
+        grub.version_add(vyos_ver, root_dir, boot_opts)
+
+    # update structure version
+    grub.write_cfg_ver(CFG_VER, root_dir)
+    exit(0)
diff --git a/src/systemd/vyos-grub-update.service b/src/systemd/vyos-grub-update.service
new file mode 100644
index 000000000..522b13a33
--- /dev/null
+++ b/src/systemd/vyos-grub-update.service
@@ -0,0 +1,14 @@
+[Unit]
+Description=Update GRUB loader configuration structure
+After=local-fs.target
+Before=vyos-router.service
+
+[Service]
+Type=oneshot
+ExecStart=/usr/libexec/vyos/system/grub_update.py
+TimeoutSec=5
+KillMode=process
+StandardOutput=journal+console
+
+[Install]
+WantedBy=vyos-router.service
\ No newline at end of file