CasperSecurity
#!/usr/bin/python3
#
# Copyright (C) 2018 Canonical, Ltd.
# Author: Mathieu Trudel-Lapierre <mathieu.trudel-lapierre@canonical.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 3.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
'''netplan configuration manager'''
import logging
import os
import shutil
import sys
import tempfile
from typing import Optional
from netplan import libnetplan
class ConfigManager(object):
def __init__(self, prefix="/", extra_files={}):
self.prefix = prefix
self.tempdir = tempfile.mkdtemp(prefix='netplan_')
self.temp_etc = os.path.join(self.tempdir, "etc")
self.temp_run = os.path.join(self.tempdir, "run")
self.extra_files = extra_files
self.new_interfaces = set()
self.np_state: Optional[libnetplan.State] = None
def __getattr__(self, attr):
assert self.np_state is not None, "Must call parse() before accessing the config."
return getattr(self.np_state, attr)
@property
def physical_interfaces(self):
assert self.np_state is not None, "Must call parse() before accessing the config."
interfaces = {}
interfaces.update(self.np_state.ethernets)
interfaces.update(self.np_state.modems)
interfaces.update(self.np_state.wifis)
return interfaces
@property
def virtual_interfaces(self):
assert self.np_state is not None, "Must call parse() before accessing the config."
interfaces = {}
# what about ovs_ports?
interfaces.update(self.np_state.bridges)
interfaces.update(self.np_state.bonds)
interfaces.update(self.np_state.tunnels)
interfaces.update(self.np_state.vlans)
interfaces.update(self.np_state.vrfs)
return interfaces
def parse(self, extra_config=None):
"""
Parse all our config files to return an object that describes the system's
entire configuration, so that it can later be interrogated.
Returns a libnetplan State wrapper
"""
# /run/netplan shadows /etc/netplan/, which shadows /lib/netplan
parser = libnetplan.Parser()
try:
parser.load_yaml_hierarchy(rootdir=self.prefix)
if extra_config:
for f in extra_config:
parser.load_yaml(f)
self.np_state = libnetplan.State()
self.np_state.import_parser_results(parser)
except libnetplan.LibNetplanException as e:
raise ConfigurationError(*e.args)
self.np_state.dump_to_logs()
return self.np_state
def add(self, config_dict):
for config_file in config_dict:
self._copy_file(config_file, config_dict[config_file])
self.extra_files.update(config_dict)
# Invalidate the current parsed state
self.np_state = None
def backup(self, backup_config_dir=True):
if backup_config_dir:
self._copy_tree(os.path.join(self.prefix, "etc/netplan"),
os.path.join(self.temp_etc, "netplan"))
self._copy_tree(os.path.join(self.prefix, "run/NetworkManager/system-connections"),
os.path.join(self.temp_run, "NetworkManager", "system-connections"),
missing_ok=True)
self._copy_tree(os.path.join(self.prefix, "run/systemd/network"),
os.path.join(self.temp_run, "systemd", "network"),
missing_ok=True)
def revert(self):
try:
for extra_file in dict(self.extra_files):
os.unlink(self.extra_files[extra_file])
del self.extra_files[extra_file]
temp_nm_path = "{}/NetworkManager/system-connections".format(self.temp_run)
temp_networkd_path = "{}/systemd/network".format(self.temp_run)
if os.path.exists(temp_nm_path):
shutil.rmtree(os.path.join(self.prefix, "run/NetworkManager/system-connections"))
self._copy_tree(temp_nm_path,
os.path.join(self.prefix, "run/NetworkManager/system-connections"))
if os.path.exists(temp_networkd_path):
shutil.rmtree(os.path.join(self.prefix, "run/systemd/network"))
self._copy_tree(temp_networkd_path,
os.path.join(self.prefix, "run/systemd/network"))
except Exception as e: # pragma: nocover (only relevant to filesystem failures)
# If we reach here, we're in big trouble. We may have wiped out
# file NM or networkd are using, and we most likely removed the
# "new" config -- or at least our copy of it.
# Given that we're in some halfway done revert; warn the user
# aggressively and drop everything; leaving any remaining backups
# around for the user to handle themselves.
logging.error("Something really bad happened while reverting config: {}".format(e))
logging.error("You should verify the netplan YAML in /etc/netplan and probably run 'netplan apply' again.")
sys.exit(-1)
def cleanup(self):
shutil.rmtree(self.tempdir)
def __del__(self):
try:
self.cleanup()
except FileNotFoundError:
# If cleanup() was called before, there is nothing to delete
pass
def _copy_file(self, src, dst):
shutil.copy(src, dst)
def _copy_tree(self, src, dst, missing_ok=False):
try:
shutil.copytree(src, dst)
except FileNotFoundError:
if missing_ok:
pass
else:
raise
class ConfigurationError(Exception):
"""
Configuration could not be parsed or has otherwise failed to apply
"""
pass