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Fixes #5469 Refactor sysctl module into object oriented code,

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and add a sysctl_set parameter to manage the values in /proc
This commit is contained in:
James Tanner 2014-01-13 18:53:02 -05:00
parent 3a83cf1d6c
commit ca05584495
1 changed files with 166 additions and 227 deletions
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393
library/system/sysctl
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@ -2,6 +2,7 @@
# -*- 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
#
@ -41,19 +42,9 @@ options:
aliases: [ 'val' ]
state:
description:
- Whether the entry should be present or absent.
- Whether the entry should be present or absent in the sysctl file.
choices: [ "present", "absent" ]
default: present
checks:
description:
- If C(none), no smart/facultative checks will be made. If
C(before), some checks are performed before any update (i.e. is
the sysctl key writable?). If C(after), some checks are performed
after an update (i.e. does kernel return the set value?). If
C(both), all of the smart checks (C(before) and C(after)) are
performed.
choices: [ "none", "before", "after", "both" ]
default: both
reload:
description:
- If C(yes), performs a I(/sbin/sysctl -p) if the C(sysctl_file) is
@ -66,6 +57,13 @@ options:
- 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>
@ -78,10 +76,14 @@ EXAMPLES = '''
# 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, check if the sysctl key
# seems writable, but do not reload sysctl, and do not check kernel value
# after (not needed, because the real /etc/sysctl.conf was not updated)
- sysctl: name=kernel.panic value=3 sysctl_file=/tmp/test_sysctl.conf checks=before reload=no
# 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
'''
# ==============================================================
@ -90,137 +92,168 @@ import os
import tempfile
import re
# ==============================================================
class SysctlModule(object):
def reload_sysctl(module, **sysctl_args):
# update needed ?
if not sysctl_args['reload']:
return 0, ''
def __init__(self, module):
self.module = module
self.args = self.module.params
# do it
if get_platform().lower() == 'freebsd':
# freebsd doesn't support -p, so reload the sysctl service
rc,out,err = module.run_command('/etc/rc.d/sysctl reload')
else:
# system supports reloading via the -p flag to sysctl, so we'll use that
sysctl_cmd = module.get_bin_path('sysctl', required=True)
rc,out,err = module.run_command([sysctl_cmd, '-p', sysctl_args['sysctl_file']])
return rc,out+err
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
def write_sysctl(module, lines, **sysctl_args):
# open a tmp file
fd, tmp_path = tempfile.mkstemp('.conf', '.ansible_m_sysctl_', os.path.dirname(sysctl_args['sysctl_file']))
f = open(tmp_path,"w")
try:
for l in lines:
f.write(l)
except IOError, e:
module.fail_json(msg="Failed to write to file %s: %s" % (tmp_path, str(e)))
f.flush()
f.close()
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
# replace the real one
module.atomic_move(tmp_path, sysctl_args['sysctl_file'])
self.process()
# end
return sysctl_args
# ==============================================================
# LOGIC
# ==============================================================
# ==============================================================
def process(self):
def sysctl_args_expand(**sysctl_args):
if get_platform().lower() == 'freebsd':
# FreeBSD does not use the /proc file system, and instead
# just uses the sysctl command to set the values
sysctl_args['key_path'] = None
else:
sysctl_args['key_path'] = sysctl_args['name'].replace('.' ,'/')
sysctl_args['key_path'] = '/proc/sys/' + sysctl_args['key_path']
return sysctl_args
# Whitespace is bad
self.args['name'] = self.args['name'].strip()
self.args['value'] = self.args['value'].strip()
# ==============================================================
thisname = self.args['name']
def sysctl_args_collapse(**sysctl_args):
# go ahead
if sysctl_args.get('key_path') is not None:
del sysctl_args['key_path']
if sysctl_args['state'] == 'absent' and 'value' in sysctl_args:
del sysctl_args['value']
# end
return sysctl_args
# 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
def sysctl_check(module, current_step, **sysctl_args):
# no smart checks at this step ?
if sysctl_args['checks'] == 'none':
return 0, ''
if current_step == 'before' and sysctl_args['checks'] not in ['before', 'both']:
return 0, ''
if current_step == 'after' and sysctl_args['checks'] not in ['after', 'both']:
return 0, ''
# update file contents with desired token/value
self.fix_lines()
# checking coherence
if sysctl_args['state'] == 'absent' and sysctl_args['value'] is not None:
return 1, 'value=x must not be supplied when state=absent'
if sysctl_args['state'] == 'present' and sysctl_args['value'] is None:
return 1, 'value=x must be supplied when state=present'
if not sysctl_args['reload'] and sysctl_args['checks'] in ['after', 'both']:
return 1, 'checks cannot be set to after or both if reload=no'
# 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
if sysctl_args['key_path'] is not None:
# getting file stat
if not os.access(sysctl_args['key_path'], os.F_OK):
return 1, 'key_path is not an existing file, key %s seems invalid' % sysctl_args['key_path']
if not os.access(sysctl_args['key_path'], os.R_OK):
return 1, 'key_path is not a readable file, key seems to be uncheckable'
# 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'])
# checks before
if current_step == 'before' and sysctl_args['checks'] in ['before', 'both']:
if sysctl_args['key_path'] is not None and not os.access(sysctl_args['key_path'], os.W_OK):
return 1, 'key_path is not a writable file, key seems to be read only'
return 0, ''
# ==============================================================
# SYSCTL COMMAND MANAGEMENT
# ==============================================================
# checks after
if current_step == 'after' and sysctl_args['checks'] in ['after', 'both']:
if sysctl_args['value'] is not None:
if sysctl_args['key_path'] is not None:
# reading the virtual file
f = open(sysctl_args['key_path'],'r')
output = f.read()
f.close()
else:
# we're on a system without /proc (ie. freebsd), so just
# use the sysctl command to get the currently set value
sysctl_cmd = module.get_bin_path('sysctl', required=True)
rc,output,stderr = module.run_command("%s -n %s" % (sysctl_cmd, sysctl_args['name']))
if rc != 0:
return 1, 'failed to lookup the value via the sysctl command'
output = output.strip(' \t\n\r')
output = re.sub(r'\s+', ' ', output)
# normal case, found value must be equal to the submitted value, and
# we compare the exploded values to handle any whitepsace differences
if output.split() != sysctl_args['value'].split():
return 1, 'key seems not set to value even after update/sysctl, founded : <%s>, wanted : <%s>' % (output, sysctl_args['value'])
return 0, ''
# 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:
# no value was supplied, so we're checking to make sure
# the associated name is absent. We just fudge this since
# the sysctl isn't really gone, just removed from the conf
# file meaning it will be whatever the system default is
return 0, ''
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)
# weird end
return 1, 'unexpected position reached'
# ==============================================================
# main
@ -233,110 +266,16 @@ def main():
name = dict(aliases=['key'], required=True),
value = dict(aliases=['val'], required=False),
state = dict(default='present', choices=['present', 'absent']),
checks = dict(default='both', choices=['none', 'before', 'after', 'both']),
reload = dict(default=True, type='bool'),
sysctl_set = dict(default=True, type='bool'),
sysctl_file = dict(default='/etc/sysctl.conf')
)
),
supports_check_mode=True
)
# defaults
sysctl_args = {
'changed': False,
'name': module.params['name'],
'state': module.params['state'],
'checks': module.params['checks'],
'reload': module.params['reload'],
'value': module.params.get('value'),
'sysctl_file': module.params['sysctl_file']
}
# prepare vars
sysctl_args = sysctl_args_expand(**sysctl_args)
if get_platform().lower() == 'freebsd':
# freebsd does not like spaces around the equal sign
pattern = "%s=%s\n"
else:
pattern = "%s = %s\n"
new_line = pattern % (sysctl_args['name'], sysctl_args['value'])
to_write = []
founded = False
# make checks before act
res,msg = sysctl_check(module, 'before', **sysctl_args)
if res != 0:
module.fail_json(msg='checks_before failed with: ' + msg)
result = SysctlModule(module)
if not os.access(sysctl_args['sysctl_file'], os.W_OK):
try:
f = open(sysctl_args['sysctl_file'],'w')
f.close()
except IOError, e:
module.fail_json(msg='unable to create supplied sysctl file (destination directory probably missing)')
# reading the file
for line in open(sysctl_args['sysctl_file'], 'r').readlines():
if not line.strip():
to_write.append(line)
continue
if line.strip().startswith('#'):
to_write.append(line)
continue
# write line if not the one searched
ld = {}
ld['name'], ld['val'] = line.split('=',1)
ld['name'] = ld['name'].strip()
if ld['name'] != sysctl_args['name']:
to_write.append(line)
continue
# should be absent ?
if sysctl_args['state'] == 'absent':
# not writing the founded line
# mark as changed
sysctl_args['changed'] = True
# should be present
if sysctl_args['state'] == 'present':
# is the founded line equal to the wanted one ?
ld['val'] = ld['val'].strip()
if ld['val'] == sysctl_args['value']:
# line is equal, writing it without update (but cancel repeats)
if sysctl_args['changed'] == False and founded == False:
to_write.append(line)
founded = True
else:
# update the line (but cancel repeats)
if sysctl_args['changed'] == False and founded == False:
to_write.append(new_line)
sysctl_args['changed'] = True
continue
# if not changed, but should be present, so we have to add it
if sysctl_args['state'] == 'present' and sysctl_args['changed'] == False and founded == False:
to_write.append(new_line)
sysctl_args['changed'] = True
# has changed ?
res = 0
if sysctl_args['changed'] == True:
sysctl_args = write_sysctl(module, to_write, **sysctl_args)
res,msg = reload_sysctl(module, **sysctl_args)
# make checks after act
res,msg = sysctl_check(module, 'after', **sysctl_args)
if res != 0:
module.fail_json(msg='checks_after failed with: ' + msg)
# look at the next link to avoid this workaround
# https://groups.google.com/forum/?fromgroups=#!topic/ansible-project/LMY-dwF6SQk
changed = sysctl_args['changed']
del sysctl_args['changed']
# end
sysctl_args = sysctl_args_collapse(**sysctl_args)
module.exit_json(changed=changed, **sysctl_args)
module.exit_json(changed=result.changed)
sys.exit(0)
# import module snippets