ansible/library/cron
Mike Grozak 171a01deac Cron module upgrades
- added cron_file attribute: if specified, the file with appropriate
job is created in /etc/cron.d directory. Also, you can store multiple
jobs in one file. state='absent' attribute is handled in the following
way in this case: if after the deletion of the job from the file specified
by cron_file variable the file is empty, the file is deleted, otherwise
not.
  - fixed the behaviour, when the backupfile is saved forever in /tmp
folder, even if the backup= atribute is not set (os.unlink() is called if
backup is not True).
  - added some comments to the unobvious places
2013-02-09 11:11:19 -05:00

368 lines
12 KiB
Python

#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# (c) 2012, Dane Summers <dsummers@pinedesk.biz>
# (c) 2013, Mike Grozak <mike.grozak@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/>.
# Cron Plugin: The goal of this plugin is to provide an indempotent method for
# setting up cron jobs on a host. The script will play well with other manually
# entered crons. Each cron job entered will be preceded with a comment
# describing the job so that it can be found later, which is required to be
# present in order for this plugin to find/modify the job.
DOCUMENTATION = '''
---
module: cron
short_description: Manage crontab entries.
description:
- Use this module to manage crontab entries. This module allows you to create named
crontab entries, update, or delete them.
- 'The module includes one line with the description of the crontab entry C("#Ansible: <name>")
corresponding to the "name" passed to the module, which is used by future ansible/module calls
to find/check the state.'
version_added: "0.9"
options:
name:
description:
- Description of a crontab entry.
required: true
default:
aliases: []
user:
description:
- The specific user who's crontab should be modified.
required: false
default: root
aliases: []
job:
description:
- The command to execute.
- Required if state=present.
required: false
default:
aliases: []
state:
description:
- Whether to ensure the job is present or absent.
- If the cron_file setting is specified and the state is 'absent', if after the deletion
of the job the file is empty, the file is deleted
required: false
default: present
aliases: []
cron_file:
descrition:
- The file with appropriate job is created in /etc/cron.d directory. Also, you can store
multiple jobs in one file.
required: fasle
default:
aliases: []
backup:
description:
- If set, then create a backup of the crontab before it is modified.
- The location of the backup is returned in the C(backup) variable by this module.
required: false
default: false
aliases: []
minute:
description:
- Minute when the job should run ( 0-59, *, */2, etc )
required: false
default: "*"
aliases: []
hour:
description:
- Hour when the job should run ( 0-23, *, */2, etc )
required: false
default: "*"
aliases: []
day:
description:
- Day of the month the job should run ( 1-31, *, */2, etc )
required: false
default: "*"
aliases: []
month:
description:
- Month of the year the job should run ( 1-12, *, */2, etc )
required: false
default: "*"
aliases: []
weekday:
description:
- Day of the week that the job should run ( 0-7 for Sunday - Saturday, or mon, tue, * etc )
required: false
default: "*"
aliases: []
reboot:
description:
- If the job should be run at reboot, will ignore minute, hour, day, and month settings in favour of C(@reboot)
version_added: "1.0"
required: false
default: False
aliases: []
examples:
- code: 'cron: name="check dirs" hour="5,2" job="ls -alh > /dev/null"'
description: Ensure a job that runs at 2 and 5 exists. Creates an entry like "* 5,2 * * ls -alh > /dev/null"
- code: 'cron: name="an old job" cron job="/some/dir/job.sh" state=absent'
description: 'Ensure an old job is no longer present. Removes any job that is preceded by "#Ansible: an old job" in the crontab'
- code: 'cron: name="a job for reboot" reboot=True job="/some/job.sh"'
description: 'Creates an entry like "@reboot /some/job.sh"'
- code: 'cron: name="yum autoupdate" weekday="2" minute=0 hour=12 user="root" job="YUMINTERACTIVE=0 /usr/sbin/yum-autoupdate" cron_file=ansible_yum-autoupdate
requirements: cron
author: Dane Summers
updates: Mike Grozak
'''
import re
import tempfile
def get_jobs_file(module, user, tmpfile, cron_file):
if cron_file:
cmd = "cp -fp /etc/cron.d/%s %s" % (cron_file, tmpfile)
else:
cmd = "crontab -l %s > %s" % (user,tmpfile)
return module.run_command(cmd)
def install_jobs(module, user, tmpfile, cron_file):
if cron_file:
cmd = "ln -f %s /etc/cron.d/%s" % (tmpfile, cron_file)
else:
cmd = "crontab %s %s" % (user, tmpfile)
return module.run_command(cmd)
def get_jobs(tmpfile):
lines = open(tmpfile).read().splitlines()
comment = None
jobs = []
for l in lines:
if comment is not None:
jobs.append([comment,l])
comment = None
elif re.match( r'#Ansible: ',l):
comment = re.sub( r'#Ansible: ', '', l)
return jobs
def find_job(name,tmpfile):
jobs = get_jobs(tmpfile)
for j in jobs:
if j[0] == name:
return j
return []
def add_job(module,name,job,tmpfile):
cmd = "echo \"#Ansible: %s\n%s\" >> %s" % (name,job,tmpfile)
return module.run_command(cmd)
def update_job(name,job,tmpfile):
return _update_job(name,job,tmpfile,do_add_job)
def do_add_job(lines, comment, job):
lines.append(comment)
lines.append(job)
def remove_job(name,tmpfile):
return _update_job(name,"",tmpfile,do_remove_job)
def do_remove_job(lines,comment,job):
return None
def remove_job_file(cron_file):
fname = "/etc/cron.d/%s" % (cron_file)
os.unlink(fname)
def _update_job(name,job,tmpfile,addlinesfunction):
ansiblename="#Ansible: %s" % (name)
f = open(tmpfile)
lines = f.read().splitlines()
newlines = []
comment = None
for l in lines:
if comment is not None:
addlinesfunction(newlines,comment,job)
comment = None
elif l == ansiblename:
comment = l
else:
newlines.append(l)
f.close()
f = open(tmpfile,'w')
for l in newlines:
f.write(l)
f.write('\n')
f.close()
if len(newlines) == 0:
return (0,"","",True)
else:
return (0,"","",False) # TODO add some more error testing
def get_cron_job(minute,hour,day,month,weekday,job,user,cron_file,reboot):
if reboot:
if cron_file:
return "@reboot %s %s" % (user, job)
else:
return "@reboot %s" % (job)
else:
if cron_file:
return "%s %s %s %s %s %s %s" % (minute,hour,day,month,weekday,user,job)
else:
return "%s %s %s %s %s %s" % (minute,hour,day,month,weekday,job)
return None
def main():
# The following example playbooks:
# - action: cron name="check dirs" hour="5,2" job="ls -alh > /dev/null"
# - name: do the job
# action: name="do the job" cron hour="5,2" job="/some/dir/job.sh"
# - name: no job
# action: name="an old job" cron job="/some/dir/job.sh" state=absent
#
# Would produce:
# # Ansible: check dirs
# * * 5,2 * * ls -alh > /dev/null
# # Ansible: do the job
# * * 5,2 * * /some/dir/job.sh
# Function:
# 1. dump the existing cron:
# crontab -l -u <user> > /tmp/tmpfile
# 2. search for comment "^# Ansible: <name>" followed by a cron.
# 3. if absent: remove if present (and say modified), otherwise return with no mod.
# 4. if present: if the same return no mod, if not present add (and say mod), if different add (and say mod)
# 5. Install new cron (if mod):
# crontab -u <user> /tmp/tmpfile
# 6. return mod
module = AnsibleModule(
argument_spec = dict(
name=dict(required=True),
user=dict(required=False),
job=dict(required=False),
cron_file=dict(required=False),
state=dict(default='present', choices=['present', 'absent']),
backup=dict(default=False, choices=BOOLEANS),
minute=dict(default='*'),
hour=dict(default='*'),
day=dict(default='*'),
month=dict(default='*'),
weekday=dict(default='*'),
reboot=dict(required=False, default=False, choices=BOOLEANS)
)
)
backup = module.boolean(module.params.get('backup', False))
name = module.params['name']
user = module.params['user']
job = module.params['job']
cron_file = module.params['cron_file']
minute = module.params['minute']
hour = module.params['hour']
day = module.params['day']
month = module.params['month']
weekday = module.params['weekday']
reboot = module.boolean(module.params.get('reboot', False))
state = module.params['state']
do_install = module.params['state'] == 'present'
changed = False
if reboot and (True in [(x != '*') for x in [minute, hour, day, month, weekday]]):
module.fail_json(msg="You must specify either reboot=True or any of minute, hour, day, month, weekday")
if cron_file:
if not user:
module.fail_json(msg="To use file=... parameter you must specify user=... as well")
else:
if not user:
user = ""
else:
user = "-u %s" % (user)
job = get_cron_job(minute,hour,day,month,weekday,job,user,cron_file,reboot)
rc, out, err, rm, status = (0, None, None, None, None)
if job is None and do_install:
module.fail_json(msg="You must specify 'job' to install a new cron job")
tmpfile = tempfile.NamedTemporaryFile()
(rc, out, err) = get_jobs_file(module,user,tmpfile.name, cron_file)
if rc != 0 and rc != 1: # 1 can mean that there are no jobs.
module.fail_json(msg=err)
(handle,backupfile) = tempfile.mkstemp(prefix='crontab')
(rc, out, err) = get_jobs_file(module,user,backupfile, cron_file)
if rc != 0 and rc != 1:
module.fail_json(msg=err)
old_job = find_job(name,backupfile)
if do_install:
if len(old_job) == 0:
(rc, out, err) = add_job(module,name,job,tmpfile.name)
changed = True
if len(old_job) > 0 and old_job[1] != job:
(rc, out, err) = update_job(name,job,tmpfile.name)
changed = True
else:
if len(old_job) > 0:
# if rm is true after the next line, file will be deleted afterwards
(rc, out, err, rm) = remove_job(name,tmpfile.name)
changed = True
else:
# there is no old_jobs for deletion - we should leave everything
# as is. If the file is empty, it will be removed later
tmpfile.close()
# the file created by mks should be deleted explicitly
os.unlink(backupfile)
module.exit_json(changed=changed,cron_file=cron_file,state=state)
if (rc != 0):
module.fail_json(msg=err)
if changed:
# If the file is empty - remove it
if rm:
remove_job_file(cron_file)
else:
if backup:
module.backup_local(backupfile)
(rc, out, err) = install_jobs(module,user,tmpfile.name, cron_file)
if (rc != 0):
module.fail_json(msg=err)
# get the list of jobs in file
jobnames = []
for j in get_jobs(tmpfile.name):
jobnames.append(j[0])
tmpfile.close()
if not backup:
os.unlink(backupfile)
module.exit_json(changed=changed,jobs=jobnames)
else:
module.exit_json(changed=changed,jobs=jobnames,backup=backupfile)
# include magic from lib/ansible/module_common.py
#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
main()