# -*- coding: utf-8 -*-
# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2019 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENSE.TXT
import os
import subprocess
# The child interpreter acts on PYTHON* before the spawned script's first
# statement, so it must not inherit them. Keep by name, not drop by name: a drop
# list stops covering every name nobody listed and every name CPython adds later.
# PYTHONWARNINGS is the one that must survive - sixteen scripts under
# jenkins_tests/rpm_tests/p_lve-utils/ set PYTHONWARNINGS=error::UnicodeWarning
# and then drive lve-utils binaries, and fifteen of them assert only on exit
# codes, so dropping it would turn their detection into a silent no-op rather
# than a visible failure. Analysis: CLOS-5881.
CHILD_PYTHON_VARS_KEPT = ("PYTHONWARNINGS",)
# The dynamic linker and the locale loader act earlier still, and no interpreter
# flag suppresses these. lvectl loads the pylve C extension, so the linker is in
# play for this child.
CHILD_LOADER_VAR_PREFIX = "LD_"
CHILD_LOADER_VARS = ("GCONV_PATH", "NLSPATH")
def isolated_child_env():
"""
Builds the environment for a root utility spawned by exec_utility().
Removes the variables that let the child interpreter or its dynamic linker
resolve code from a location this process did not choose, and keeps the rest
so the child behaves exactly as it does under an inherited environment.
:return: dict to hand to exec_utility(env=...)
:rtype: dict[str, str]
"""
env = {}
for name, value in os.environ.items():
if name.startswith("PYTHON") and name not in CHILD_PYTHON_VARS_KEPT:
continue
if name.startswith(CHILD_LOADER_VAR_PREFIX) or name in CHILD_LOADER_VARS:
continue
env[name] = value
# Assert the user-site suppression here instead of inheriting it from the
# venv's pyvenv.cfg, which a different package owns.
env["PYTHONNOUSERSITE"] = "1"
return env
def exec_utility(util_path, params, stderr=False, env=None):
"""
Executes supplied utility with supplied parameters
:param util_path: string with path to callable utility
:param params: utility parameters
:param stderr: trigger to return stderr or not
:param env: environment for the child; None inherits this process' own
:return: Cortege (ret_code, cagefsctl_stdout) if stderr is False
Cortege (ret_code, cagefsctl_stdout, cagefsctl_stderr) otherwise
"""
args = []
args.append(util_path)
args.extend(params)
with subprocess.Popen(
args,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
text=True,
env=env,
) as proc:
out, err = proc.communicate()
retcode = proc.returncode
if stderr:
return retcode, out.strip(), err.strip()
return retcode, out.strip()
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