charm-plumgrid-gateway/hooks/charmhelpers/contrib/hardening/audits/apache.py

101 lines
3.4 KiB
Python

# Copyright 2016 Canonical Limited.
#
# This file is part of charm-helpers.
#
# charm-helpers is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License version 3 as
# published by the Free Software Foundation.
#
# charm-helpers 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 Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with charm-helpers. If not, see <http://www.gnu.org/licenses/>.
import re
import subprocess
from six import string_types
from charmhelpers.core.hookenv import (
log,
INFO,
ERROR,
)
from charmhelpers.contrib.hardening.audits import BaseAudit
class DisabledModuleAudit(BaseAudit):
"""Audits Apache2 modules.
Determines if the apache2 modules are enabled. If the modules are enabled
then they are removed in the ensure_compliance.
"""
def __init__(self, modules):
if modules is None:
self.modules = []
elif isinstance(modules, string_types):
self.modules = [modules]
else:
self.modules = modules
def ensure_compliance(self):
"""Ensures that the modules are not loaded."""
if not self.modules:
return
try:
loaded_modules = self._get_loaded_modules()
non_compliant_modules = []
for module in self.modules:
if module in loaded_modules:
log("Module '%s' is enabled but should not be." %
(module), level=INFO)
non_compliant_modules.append(module)
if len(non_compliant_modules) == 0:
return
for module in non_compliant_modules:
self._disable_module(module)
self._restart_apache()
except subprocess.CalledProcessError as e:
log('Error occurred auditing apache module compliance. '
'This may have been already reported. '
'Output is: %s' % e.output, level=ERROR)
@staticmethod
def _get_loaded_modules():
"""Returns the modules which are enabled in Apache."""
output = subprocess.check_output(['apache2ctl', '-M'])
modules = []
for line in output.strip().split():
# Each line of the enabled module output looks like:
# module_name (static|shared)
# Plus a header line at the top of the output which is stripped
# out by the regex.
matcher = re.search(r'^ (\S*)', line)
if matcher:
modules.append(matcher.group(1))
return modules
@staticmethod
def _disable_module(module):
"""Disables the specified module in Apache."""
try:
subprocess.check_call(['a2dismod', module])
except subprocess.CalledProcessError as e:
# Note: catch error here to allow the attempt of disabling
# multiple modules in one go rather than failing after the
# first module fails.
log('Error occurred disabling module %s. '
'Output is: %s' % (module, e.output), level=ERROR)
@staticmethod
def _restart_apache():
"""Restarts the apache process"""
subprocess.check_output(['service', 'apache2', 'restart'])