Script to do VMDK disk reset after reboot

reset_boot_disk.py

#!/usr/bin/env python
""" Reset disk for VirtualBox vmdk
"""

import os.path as op
from subprocess import check_output
import plistlib
import re
from argparse import ArgumentParser, RawDescriptionHelpFormatter


DISK_RE = re.compile(r'"/dev/disk\d+"')


def get_disk_for_uuid(disk_uuid):
    disk_out = check_output(['diskutil', 'list', '-plist'])

    disk_info = plistlib.loads(disk_out)
    disks = disk_info['AllDisksAndPartitions']
    target_disk = None
    for di in disks:
        if not 'Partitions' in di:
            continue
        for partition in di['Partitions']:
            if partition.get('DiskUUID') == disk_uuid:
                target_disk = di['DeviceIdentifier']
                break
    return '/dev/' + target_disk


def set_target_disk(vmdk_fname, target_disk):
    vmdk_fname = op.expanduser(vmdk_fname)
    with open(vmdk_fname, 'rt') as fobj:
        contents = fobj.read()
    if not DISK_RE.search(contents):
        raise RuntimeError(
            f"Could not find disk id in vmdk file {vmdk_fname}")
    with open(vmdk_fname + '.bak', 'wt') as fobj:
        fobj.write(contents)
    contents = DISK_RE.sub(f'"{target_disk}"', contents)
    with open(vmdk_fname, 'wt') as fobj:
        fobj.write(contents)


def get_parser():
    parser = ArgumentParser(description=__doc__,  # Usage from docstring
                            formatter_class=RawDescriptionHelpFormatter)
    parser.add_argument('vmdk_fname',
                        help='VMDK filename')
    parser.add_argument('disk_uuid',
                        default='5C4BE972-BB2D-4ABF-934A-4A57B585EBFA',
                        help='UUID for disk partition')
    return parser


def main():
    parser = get_parser()
    args = parser.parse_args()
    target_disk = get_disk_for_uuid(args.disk_uuid)
    if target_disk is None:
        raise RuntimeError(f'Could not find disk {args.disk_uuid}')
    set_target_disk(args.vmdk_fname, target_disk)
    # https://apple.stackexchange.com/a/339445/100293
    print(f"""\
sudo chown ${{USER}} {target_disk}
sudo chmod 660 {target_disk}""")


if __name__ == '__main__':
    main()