charm-hacluster/hooks/charmhelpers/core/kernel.py

69 lines
2.0 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright 2014-2015 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/>.
__author__ = "Jorge Niedbalski <jorge.niedbalski@canonical.com>"
from charmhelpers.core.hookenv import (
log,
INFO
)
from subprocess import check_call, check_output
import re
def modprobe(module, persist=True):
"""Load a kernel module and configure for auto-load on reboot."""
cmd = ['modprobe', module]
log('Loading kernel module %s' % module, level=INFO)
check_call(cmd)
if persist:
with open('/etc/modules', 'r+') as modules:
if module not in modules.read():
modules.write(module)
def rmmod(module, force=False):
"""Remove a module from the linux kernel"""
cmd = ['rmmod']
if force:
cmd.append('-f')
cmd.append(module)
log('Removing kernel module %s' % module, level=INFO)
return check_call(cmd)
def lsmod():
"""Shows what kernel modules are currently loaded"""
return check_output(['lsmod'],
universal_newlines=True)
def is_module_loaded(module):
"""Checks if a kernel module is already loaded"""
matches = re.findall('^%s[ ]+' % module, lsmod(), re.M)
return len(matches) > 0
def update_initramfs(version='all'):
"""Updates an initramfs image"""
return check_call(["update-initramfs", "-k", version, "-u"])