113 lines
3.3 KiB
Python
113 lines
3.3 KiB
Python
|
import calendar
|
||
|
|
import datetime
|
||
|
|
import logging
|
||
|
|
import os
|
||
|
|
import time
|
||
|
|
import warnings
|
||
|
|
|
||
|
|
try:
|
||
|
|
import zoneinfo # pragma: no cover
|
||
|
|
except ImportError:
|
||
|
|
from backports import zoneinfo # pragma: no cover
|
||
|
|
|
||
|
|
from tzlocal import windows_tz
|
||
|
|
|
||
|
|
log = logging.getLogger("tzlocal")
|
||
|
|
|
||
|
|
|
||
|
|
def get_tz_offset(tz):
|
||
|
|
"""Get timezone's offset using built-in function datetime.utcoffset()."""
|
||
|
|
return int(datetime.datetime.now(tz).utcoffset().total_seconds())
|
||
|
|
|
||
|
|
|
||
|
|
def assert_tz_offset(tz, error=True):
|
||
|
|
"""Assert that system's timezone offset equals to the timezone offset found.
|
||
|
|
|
||
|
|
If they don't match, we probably have a misconfiguration, for example, an
|
||
|
|
incorrect timezone set in /etc/timezone file in systemd distributions.
|
||
|
|
|
||
|
|
If error is True, this method will raise a ValueError, otherwise it will
|
||
|
|
emit a warning.
|
||
|
|
"""
|
||
|
|
|
||
|
|
tz_offset = get_tz_offset(tz)
|
||
|
|
system_offset = calendar.timegm(time.localtime()) - calendar.timegm(time.gmtime())
|
||
|
|
# No one has timezone offsets less than a minute, so this should be close enough:
|
||
|
|
if abs(tz_offset - system_offset) > 60:
|
||
|
|
msg = (
|
||
|
|
f"Timezone offset does not match system offset: {tz_offset} != {system_offset}. "
|
||
|
|
"Please, check your config files."
|
||
|
|
)
|
||
|
|
if error:
|
||
|
|
raise ValueError(msg)
|
||
|
|
warnings.warn(msg)
|
||
|
|
|
||
|
|
|
||
|
|
def _tz_name_from_env(tzenv=None):
|
||
|
|
if tzenv is None:
|
||
|
|
tzenv = os.environ.get("TZ")
|
||
|
|
|
||
|
|
if not tzenv:
|
||
|
|
return None
|
||
|
|
|
||
|
|
log.debug(f"Found a TZ environment: {tzenv}")
|
||
|
|
|
||
|
|
if tzenv[0] == ":":
|
||
|
|
tzenv = tzenv[1:]
|
||
|
|
|
||
|
|
if tzenv in windows_tz.tz_win:
|
||
|
|
# Yup, it's a timezone
|
||
|
|
return tzenv
|
||
|
|
|
||
|
|
if os.path.isabs(tzenv) and os.path.exists(tzenv):
|
||
|
|
# It's a file specification, expand it, if possible
|
||
|
|
parts = os.path.realpath(tzenv).split(os.sep)
|
||
|
|
|
||
|
|
# Is it a zone info zone?
|
||
|
|
possible_tz = "/".join(parts[-2:])
|
||
|
|
if possible_tz in windows_tz.tz_win:
|
||
|
|
# Yup, it is
|
||
|
|
return possible_tz
|
||
|
|
|
||
|
|
# Maybe it's a short one, like UTC?
|
||
|
|
if parts[-1] in windows_tz.tz_win:
|
||
|
|
# Indeed
|
||
|
|
return parts[-1]
|
||
|
|
|
||
|
|
log.debug("TZ does not contain a time zone name")
|
||
|
|
return None
|
||
|
|
|
||
|
|
|
||
|
|
def _tz_from_env(tzenv=None):
|
||
|
|
if tzenv is None:
|
||
|
|
tzenv = os.environ.get("TZ")
|
||
|
|
|
||
|
|
if not tzenv:
|
||
|
|
return None
|
||
|
|
|
||
|
|
# Some weird format that exists:
|
||
|
|
if tzenv[0] == ":":
|
||
|
|
tzenv = tzenv[1:]
|
||
|
|
|
||
|
|
# TZ specifies a file
|
||
|
|
if os.path.isabs(tzenv) and os.path.exists(tzenv):
|
||
|
|
# Try to see if we can figure out the name
|
||
|
|
tzname = _tz_name_from_env(tzenv)
|
||
|
|
if not tzname:
|
||
|
|
# Nope, not a standard timezone name, just take the filename
|
||
|
|
tzname = tzenv.split(os.sep)[-1]
|
||
|
|
with open(tzenv, "rb") as tzfile:
|
||
|
|
return zoneinfo.ZoneInfo.from_file(tzfile, key=tzname)
|
||
|
|
|
||
|
|
# TZ must specify a zoneinfo zone.
|
||
|
|
try:
|
||
|
|
tz = zoneinfo.ZoneInfo(tzenv)
|
||
|
|
# That worked, so we return this:
|
||
|
|
return tz
|
||
|
|
except zoneinfo.ZoneInfoNotFoundError:
|
||
|
|
# Nope, it's something like "PST4DST" etc, we can't handle that.
|
||
|
|
raise zoneinfo.ZoneInfoNotFoundError(
|
||
|
|
f"tzlocal() does not support non-zoneinfo timezones like {tzenv}. \n"
|
||
|
|
"Please use a timezone in the form of Continent/City"
|
||
|
|
) from None
|