ebsmount-udev

#!/usr/bin/python3
# Copyright (c) 2010-2021 Alon Swartz <alon@turnkeylinux.org>
# Copyright (c) 2022 TurnKey GNU/Linux <admin@turnkeylinux.org>
#
# This program 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 2 of
# the License, or (at your option) any later version.
#
# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

"""EBS Mount - triggered by udev on EBS attach and detach"""

import re
import os
import sys
import argparse

import ebsmount_lib as ebsmount
from ebsmount_lib.utils import fatal, log, config

ENVVARS = """
environment variables (required):

platfrom    env var         example value
--------    -------         -------------
AWS EC2     DEVNAME         /dev/xvdf
            PHYSDEVPATH     /devices/vbd-51792/block/xvdf

OpenStack   DEVNAME         /dev/vda
            DEVPATH         /devices/virtio-pci/virtio0/block/vda
"""


def _expected_devpath(devpath, devpaths):
    for pattern in devpaths:
        if re.search(pattern, devpath):
            return True

    return False


def main():
    parser = argparse.ArgumentParser(
        formatter_class=argparse.RawDescriptionHelpFormatter,
        prog='ebsmount-udev',
        description="EBS Mount - triggered by udev on EBS attach and detach",
        epilog=ENVVARS
    )
    parser.add_argument(
        'action',
        choices=["add", "remove"],
        help="action trigger"
    )
    args = parser.parse_args()

    if not config.enabled.lower() == "true":
        fatal(f'ebsmount is not enabled ({config.CONF_FILE})')

    devname = os.getenv('DEVNAME', None)
    devpath = os.getenv('PHYSDEVPATH', os.getenv('DEVPATH', None))

    if not devname:
        raise parser.error('DEVNAME is required')

    # it seems that these may not be needed?!
    #if not devpath:
    #    raise parser.error('PHYSDEVPATH or DEVPATH is required')

    #if not _expected_devpath(devpath, config.devpaths.split()):
    #    raise parser.error(
    #            'PHYSDEVPATH/DEVPATH is not of the expected structure')

    # log trigger
    log(devname, f"received {args.action} trigger")
    func = getattr(ebsmount, 'ebsmount_' + args.action)
    func(devname, config.mountdir)


if __name__ == "__main__":
    main()