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community.general/library/system/sysctl
James Tanner ca05584495 Fixes #5469 Refactor sysctl module into object oriented code,
and add a sysctl_set parameter to manage the values in /proc
2014-01-13 18:53:02 -05:00

283 lines
9.6 KiB
Python

#!/usr/bin/python
# -*- coding: utf-8 -*-
# (c) 2012, David "DaviXX" CHANIAL <david.chanial@gmail.com>
# (c) 2014, James Tanner <tanner.jc@gmail.com>
#
# This file is part of Ansible
#
# Ansible 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, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible 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 Ansible. If not, see <http://www.gnu.org/licenses/>.
#
DOCUMENTATION = '''
---
module: sysctl
short_description: Manage entries in sysctl.conf.
description:
- This module manipulates sysctl entries and optionally performs a C(/sbin/sysctl -p) after changing them.
version_added: "1.0"
options:
name:
description:
- The dot-separated path (aka I(key)) specifying the sysctl variable.
required: true
default: null
aliases: [ 'key' ]
value:
description:
- Desired value of the sysctl key.
required: false
default: null
aliases: [ 'val' ]
state:
description:
- Whether the entry should be present or absent in the sysctl file.
choices: [ "present", "absent" ]
default: present
reload:
description:
- If C(yes), performs a I(/sbin/sysctl -p) if the C(sysctl_file) is
updated. If C(no), does not reload I(sysctl) even if the
C(sysctl_file) is updated.
choices: [ "yes", "no" ]
default: "yes"
sysctl_file:
description:
- Specifies the absolute path to C(sysctl.conf), if not C(/etc/sysctl.conf).
required: false
default: /etc/sysctl.conf
sysctl_set:
description:
- Verify token value with the sysctl command and set with -w if necessary
choices: [ "yes", "no" ]
required: false
version_added: 1.5
default: False
notes: []
requirements: []
author: David "DaviXX" CHANIAL <david.chanial@gmail.com>
'''
EXAMPLES = '''
# Set vm.swappiness to 5 in /etc/sysctl.conf
- sysctl: name=vm.swappiness value=5 state=present
# Remove kernel.panic entry from /etc/sysctl.conf
- sysctl: name=kernel.panic state=absent sysctl_file=/etc/sysctl.conf
# Set kernel.panic to 3 in /tmp/test_sysctl.conf
- sysctl: name=kernel.panic value=3 sysctl_file=/tmp/test_sysctl.conf reload=no
# Set ip fowarding on in /proc and do not reload the sysctl file
- sysctl: name="net.ipv4.ip_forward" value=1 sysctl_set=yes
# Set ip forwarding on in /proc and in the sysctl file and reload if necessary
- sysctl: name="net.ipv4.ip_forward" value=1 sysctl_set=yes state=present reload=yes
'''
# ==============================================================
import os
import tempfile
import re
class SysctlModule(object):
def __init__(self, module):
self.module = module
self.args = self.module.params
self.sysctl_cmd = self.module.get_bin_path('sysctl', required=True)
self.sysctl_file = self.args['sysctl_file']
self.proc_value = None # current token value in proc fs
self.file_value = None # current token value in file
self.file_lines = [] # all lines in the file
self.file_values = {} # dict of token values
self.changed = False # will change occur
self.set_proc = False # does sysctl need to set value
self.write_file = False # does the sysctl file need to be reloaded
self.process()
# ==============================================================
# LOGIC
# ==============================================================
def process(self):
# Whitespace is bad
self.args['name'] = self.args['name'].strip()
self.args['value'] = self.args['value'].strip()
thisname = self.args['name']
# get the current proc fs value
self.proc_value = self.get_token_curr_value(thisname)
# get the currect sysctl file value
self.read_sysctl_file()
if thisname not in self.file_values:
self.file_values[thisname] = None
# update file contents with desired token/value
self.fix_lines()
# what do we need to do now?
if self.file_values[thisname] is None and self.args['state'] == "present":
self.changed = True
self.write_file = True
elif self.file_values[thisname] != self.args['value']:
self.changed = True
self.write_file = True
if self.args['sysctl_set']:
if self.proc_value is None:
self.changed = True
elif self.proc_value != self.args['value']:
self.changed = True
self.set_proc = True
# Do the work
if not self.module.check_mode:
if self.write_file:
self.write_sysctl()
if self.write_file and self.args['reload']:
self.reload_sysctl()
if self.set_proc:
self.set_token_value(self.args['name'], self.args['value'])
# ==============================================================
# SYSCTL COMMAND MANAGEMENT
# ==============================================================
# Use the sysctl command to find the current value
def get_token_curr_value(self, token):
thiscmd = "%s -e -n %s" % (self.sysctl_cmd, token)
rc,out,err = self.module.run_command(thiscmd)
if rc != 0:
return None
else:
return shlex.split(out)[-1]
# Use the sysctl command to set the current value
def set_token_value(self, token, value):
thiscmd = "%s -w %s=%s" % (self.sysctl_cmd, token, value)
rc,out,err = self.module.run_command(thiscmd)
if rc != 0:
self.module.fail_json(msg='setting %s failed: %s' (token, out + err))
else:
return rc
# Run sysctl -p
def reload_sysctl(self):
# do it
if get_platform().lower() == 'freebsd':
# freebsd doesn't support -p, so reload the sysctl service
rc,out,err = self.module.run_command('/etc/rc.d/sysctl reload')
else:
# system supports reloading via the -p flag to sysctl, so we'll use that
rc,out,err = self.module.run_command([self.sysctl_cmd, '-p', self.sysctl_file])
return rc,out+err
# ==============================================================
# SYSCTL FILE MANAGEMENT
# ==============================================================
# Get the token value from the sysctl file
def read_sysctl_file(self):
lines = open(self.sysctl_file, "r").readlines()
for line in lines:
line = line.strip()
self.file_lines.append(line)
# don't split empty lines or comments
if not line or line.startswith("#"):
continue
k, v = line.split('=',1)
k = k.strip()
v = v.strip()
self.file_values[k] = v.strip()
# Fix the value in the sysctl file content
def fix_lines(self):
checked = []
self.fixed_lines = []
for line in self.file_lines:
if not line.strip() or line.strip().startswith("#"):
self.fixed_lines.append(line)
continue
tmpline = line.strip()
k, v = line.split('=',1)
k = k.strip()
v = v.strip()
if k not in checked:
checked.append(k)
if k == self.args['name']:
if self.args['state'] == "present":
new_line = "%s = %s\n" % (k, self.args['value'])
self.fixed_lines.append(new_line)
else:
new_line = "%s = %s\n" % (k, v)
self.fixed_lines.append(new_line)
if self.args['name'] not in checked and self.args['state'] == "present":
new_line = "%s = %s\n" % (self.args['name'], self.args['value'])
self.fixed_lines.append(new_line)
# Completely rewrite the sysctl file
def write_sysctl(self):
# open a tmp file
fd, tmp_path = tempfile.mkstemp('.conf', '.ansible_m_sysctl_', os.path.dirname(self.sysctl_file))
f = open(tmp_path,"w")
try:
for l in self.fixed_lines:
f.write(l)
except IOError, e:
self.module.fail_json(msg="Failed to write to file %s: %s" % (tmp_path, str(e)))
f.flush()
f.close()
# replace the real one
self.module.atomic_move(tmp_path, self.sysctl_file)
# ==============================================================
# main
def main():
# defining module
module = AnsibleModule(
argument_spec = dict(
name = dict(aliases=['key'], required=True),
value = dict(aliases=['val'], required=False),
state = dict(default='present', choices=['present', 'absent']),
reload = dict(default=True, type='bool'),
sysctl_set = dict(default=True, type='bool'),
sysctl_file = dict(default='/etc/sysctl.conf')
),
supports_check_mode=True
)
result = SysctlModule(module)
module.exit_json(changed=result.changed)
sys.exit(0)
# import module snippets
from ansible.module_utils.basic import *
main()