diff options
Diffstat (limited to 'kvmd/helpers/remount/__init__.py')
| -rw-r--r-- | kvmd/helpers/remount/__init__.py | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/kvmd/helpers/remount/__init__.py b/kvmd/helpers/remount/__init__.py new file mode 100644 index 00000000..e432ca05 --- /dev/null +++ b/kvmd/helpers/remount/__init__.py @@ -0,0 +1,119 @@ +# ========================================================================== # +# # +# KVMD - The main PiKVM daemon. # +# # +# Copyright (C) 2018-2022 Maxim Devaev <[email protected]> # +# # +# 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 3 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 <https://www.gnu.org/licenses/>. # +# # +# ========================================================================== # + + +import sys +import os +import re +import shutil +import dataclasses +import subprocess + +from typing import List + + +# ==== +_MOUNT_PATH = "/bin/mount" +_FSTAB_PATH = "/etc/fstab" + + +# ===== [email protected](frozen=True) +class _Storage: + mount_path: str + root_path: str + user: str + + +# ===== +def _log(msg: str) -> None: + print(msg, file=sys.stderr) + + +def _find_storage(target: str) -> _Storage: + assert target + with open(_FSTAB_PATH) as fstab_file: + for line in fstab_file.read().split("\n"): + line = line.strip() + if line and not line.startswith("#"): + parts = line.split() + if len(parts) == 6: + options = dict(re.findall(r"X-kvmd\.%s-(root|user)=([^,]+)" % (target), parts[3])) + if options: + return _Storage( + mount_path=parts[1], + root_path=options.get("root", ""), + user=options.get("user", ""), + ) + raise SystemExit(f"Can't find {target!r} mountpoint in {_FSTAB_PATH}") + + +def _remount(path: str, rw: bool) -> None: + mode = ("rw" if rw else "ro") + _log(f"Remounting {path} to {mode.upper()}-mode ...") + try: + subprocess.check_call([_MOUNT_PATH, "--options", f"remount,{mode}", path]) + except subprocess.CalledProcessError as err: + raise SystemExit(f"Can't remount: {err}") + + +def _mkdir(path: str) -> None: + if not os.path.exists(path): + _log(f"MKDIR --- {path}") + try: + os.mkdir(path) + except Exception as err: + raise SystemExit(f"Can't create directory: {err}") + + +def _chown(path: str, user: str) -> None: + _log(f"CHOWN --- {user} - {path}") + try: + shutil.chown(path, user) + except Exception as err: + raise SystemExit(f"Can't change ownership: {err}") + + +# ===== +def main() -> None: + if len(sys.argv) != 2 or sys.argv[1] not in ["ro", "rw"]: + raise SystemExit(f"Usage: {sys.argv[0]} [ro|rw]") + + target = "" + dirs: List[str] = [] + app = os.path.basename(sys.argv[0]) + if app == "kvmd-helper-otgmsd-remount": + target = "otgmsd" + dirs = ["images", "meta"] + else: + raise SystemExit("Unknown application target") + + rw = (sys.argv[1] == "rw") + + storage = _find_storage(target) + _remount(storage.mount_path, rw) + if rw: + if storage.root_path: + for name in dirs: + path = os.path.join(storage.root_path, name) + _mkdir(path) + if storage.user: + _chown(path, storage.user) |