neutron/neutron/privileged/agent/linux/utils.py

91 lines
2.9 KiB
Python

# Copyright 2020 Red Hat, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import os
import re
from eventlet.green import subprocess
from neutron_lib.utils import helpers
from oslo_concurrency import processutils
from oslo_utils import fileutils
from neutron import privileged
NETSTAT_PIDS_REGEX = re.compile(r'.* (?P<pid>\d{2,6})/.*')
@privileged.default.entrypoint
def find_listen_pids_namespace(namespace):
return _find_listen_pids_namespace(namespace)
def _find_listen_pids_namespace(namespace):
"""Retrieve a list of pids of listening processes within the given netns
This method is implemented separately to allow unit testing.
"""
pids = set()
cmd = ['ip', 'netns', 'exec', namespace, 'netstat', '-nlp']
output = processutils.execute(*cmd)
for line in output[0].splitlines():
m = NETSTAT_PIDS_REGEX.match(line)
if m:
pids.add(m.group('pid'))
return list(pids)
@privileged.default.entrypoint
def delete_if_exists(path, remove=os.unlink):
fileutils.delete_if_exists(path, remove=remove)
@privileged.default.entrypoint
def execute_process(cmd, _process_input, addl_env):
obj, cmd = _create_process(cmd, addl_env=addl_env)
_stdout, _stderr = obj.communicate(_process_input)
returncode = obj.returncode
obj.stdin.close()
_stdout = helpers.safe_decode_utf8(_stdout)
_stderr = helpers.safe_decode_utf8(_stderr)
return _stdout, _stderr, returncode
def _addl_env_args(addl_env):
"""Build arguments for adding additional environment vars with env"""
# NOTE (twilson) If using rootwrap, an EnvFilter should be set up for the
# command instead of a CommandFilter.
if addl_env is None:
return []
return ['env'] + ['%s=%s' % pair for pair in addl_env.items()]
def _create_process(cmd, addl_env=None):
"""Create a process object for the given command.
The return value will be a tuple of the process object and the
list of command arguments used to create it.
"""
cmd = list(map(str, _addl_env_args(addl_env) + list(cmd)))
obj = subprocess.Popen(cmd, shell=False, stdin=subprocess.PIPE,
stdout=subprocess.PIPE, stderr=subprocess.PIPE)
return obj, cmd
@privileged.default.entrypoint
def kill_process(pid, signal):
"""Kill the process with the given pid using the given signal."""
os.kill(int(pid), int(signal))