ArchiveBox/archivebox/config/permissions.py

139 lines
4.8 KiB
Python

__package__ = 'archivebox.config'
import os
import pwd
import sys
import socket
import platform
from rich import print
from pathlib import Path
from contextlib import contextmanager
#############################################################################################
DATA_DIR = Path(os.getcwd())
try:
DATA_DIR_STAT = DATA_DIR.stat()
DATA_DIR_UID = DATA_DIR_STAT.st_uid
DATA_DIR_GID = DATA_DIR_STAT.st_gid
except PermissionError:
DATA_DIR_UID = 0
DATA_DIR_GID = 0
DEFAULT_PUID = 911
DEFAULT_PGID = 911
RUNNING_AS_UID = os.getuid()
RUNNING_AS_GID = os.getgid()
EUID = os.geteuid()
EGID = os.getegid()
SUDO_UID = int(os.environ.get('SUDO_UID', 0))
SUDO_GID = int(os.environ.get('SUDO_GID', 0))
USER: str = Path('~').expanduser().resolve().name
HOSTNAME: str = max([socket.gethostname(), platform.node()], key=len)
IS_ROOT = RUNNING_AS_UID == 0
IN_DOCKER = os.environ.get('IN_DOCKER', False) in ('1', 'true', 'True', 'TRUE', 'yes')
# IN_DOCKER_COMPOSE = # TODO: figure out a way to detect if running in docker compose
FALLBACK_UID = RUNNING_AS_UID or SUDO_UID
FALLBACK_GID = RUNNING_AS_GID or SUDO_GID
if RUNNING_AS_UID == 0:
try:
# if we are running as root it's really hard to figure out what the correct archivebox user should be
# as a last resort instead of setting DATA_DIR ownership to 0:0 (which breaks it for non-root users)
# check if 911:911 archivebox user exists on host system, and use it instead of 0
import pwd
if pwd.getpwuid(DEFAULT_PUID).pw_name == 'archivebox':
FALLBACK_UID = DEFAULT_PUID
FALLBACK_GID = DEFAULT_PGID
except Exception:
pass
os.environ.setdefault('PUID', str(DATA_DIR_UID or EUID or RUNNING_AS_UID or FALLBACK_UID))
os.environ.setdefault('PGID', str(DATA_DIR_GID or EGID or RUNNING_AS_GID or FALLBACK_GID))
ARCHIVEBOX_USER = int(os.environ['PUID'])
ARCHIVEBOX_GROUP = int(os.environ['PGID'])
if not USER:
try:
# alternative method 1 to get username
USER = pwd.getpwuid(ARCHIVEBOX_USER).pw_name
except Exception:
pass
if not USER:
try:
# alternative method 2 to get username
import getpass
USER = getpass.getuser()
except Exception:
pass
if not USER:
try:
# alternative method 3 to get username
USER = os.getlogin() or 'archivebox'
except Exception:
USER = 'archivebox'
ARCHIVEBOX_USER_EXISTS = False
try:
pwd.getpwuid(ARCHIVEBOX_USER)
ARCHIVEBOX_USER_EXISTS = True
except Exception:
ARCHIVEBOX_USER_EXISTS = False
#############################################################################################
def drop_privileges():
"""If running as root, drop privileges to the user that owns the data dir (or PUID)"""
# always run archivebox as the user that owns the data dir, never as root
if os.getuid() == 0:
# drop permissions to the user that owns the data dir / provided PUID
if os.geteuid() != ARCHIVEBOX_USER and ARCHIVEBOX_USER != 0 and ARCHIVEBOX_USER_EXISTS:
# drop our effective UID to the archivebox user's UID
os.seteuid(ARCHIVEBOX_USER)
# update environment variables so that subprocesses dont try to write to /root
pw_record = pwd.getpwuid(ARCHIVEBOX_USER)
os.environ['HOME'] = pw_record.pw_dir
os.environ['LOGNAME'] = pw_record.pw_name
os.environ['USER'] = pw_record.pw_name
if ARCHIVEBOX_USER == 0 or not ARCHIVEBOX_USER_EXISTS:
print('[yellow]:warning: Running as [red]root[/red] is not recommended and may make your [blue]DATA_DIR[/blue] inaccessible to other users on your system.[/yellow] (use [blue]sudo[/blue] instead)', file=sys.stderr)
@contextmanager
def SudoPermission(uid=0, fallback=False):
"""Attempt to run code with sudo permissions for a given user (or root)"""
if os.geteuid() == uid:
# no need to change effective UID, we are already that user
yield
return
try:
# change our effective UID to the given UID
os.seteuid(uid)
except PermissionError as err:
if not fallback:
raise PermissionError(f'Not enough permissions to run code as uid={uid}, please retry with sudo') from err
try:
# yield back to the caller so they can run code inside context as root
yield
finally:
# then set effective UID back to DATA_DIR owner
try:
os.seteuid(ARCHIVEBOX_USER)
except PermissionError as err:
if not fallback:
raise PermissionError(f'Failed to revert uid={uid} back to {ARCHIVEBOX_USER} after running code with sudo') from err