/usr/lib/python3/dist-packages/provisioningserver/utils/env.py is in python3-maas-provisioningserver 2.4.0~beta2-6865-gec43e47e6-0ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 | # Copyright 2014-2016 Canonical Ltd. This software is licensed under the
# GNU Affero General Public License version 3 (see the file LICENSE).
"""Environment-related utilities."""
__all__ = [
'environment_variables',
]
from contextlib import contextmanager
import os
import threading
from provisioningserver.path import get_data_path
from provisioningserver.utils.fs import (
atomic_delete,
atomic_write,
)
@contextmanager
def environment_variables(variables):
"""Context manager: temporarily set the given environment variables.
The variables are reset to their original settings afterwards.
:param variables: A dict mapping environment variables to their temporary
values.
"""
prior_environ = os.environ.copy()
os.environ.update(variables)
try:
yield
finally:
os.environ.clear()
os.environ.update(prior_environ)
# Cache the MAAS ID so we don't have to keep reading it from the filesystem.
# This avoids errors when running maas-rack register while regiond is running.
_maas_id = None
_maas_id_lock = threading.Lock()
def get_maas_id():
"""Return the system_id for this rack/region controller that is created
when either the rack or region first starts.
"""
global _maas_id
with _maas_id_lock:
if _maas_id is None:
maas_id_path = get_data_path('/var/lib/maas/maas_id')
try:
with open(maas_id_path, "r", encoding="ascii") as fp:
contents = fp.read().strip()
except FileNotFoundError:
return None
else:
_maas_id = _normalise_maas_id(contents)
return _maas_id
else:
return _maas_id
def set_maas_id(system_id):
"""Set the system_id for this rack/region permanently for MAAS."""
global _maas_id
system_id = _normalise_maas_id(system_id)
with _maas_id_lock:
maas_id_path = get_data_path('/var/lib/maas/maas_id')
if system_id is None:
try:
atomic_delete(maas_id_path)
except FileNotFoundError:
_maas_id = None # Job done already.
else:
_maas_id = None
else:
atomic_write(system_id.encode("ascii"), maas_id_path)
_maas_id = system_id
def _normalise_maas_id(system_id):
if system_id is None:
return None
else:
system_id = system_id.strip()
return None if system_id == "" else system_id
|