ansible/library/cron
2012-10-08 11:10:40 -04:00

291 lines
9.2 KiB
Python

#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# (c) 2012, Dane Summers <dsummers@pinedesk.biz>
#
# 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 include one line with the description of the crontab entry "#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.
required: false
default: present
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 '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: []
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: 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
requirements: cron
author: Dane Summers
'''
import re
import tempfile
def get_jobs_file(user,tmpfile):
cmd = "crontab -l %s > %s" % (user,tmpfile)
cmd = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
(out, err) = cmd.communicate()
rc = cmd.returncode
return (rc, out, err)
def install_jobs(user,tmpfile):
cmd = "crontab %s %s" % (user,tmpfile)
cmd = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
(out, err) = cmd.communicate()
rc = cmd.returncode
return (rc, out, err)
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(name,job,tmpfile):
cmd = "echo \"#Ansible: %s\n%s\" >> %s" % (name,job,tmpfile)
cmd = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
(out, err) = cmd.communicate()
rc = cmd.returncode
return (rc, out, err)
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 _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()
return (0,"","") # TODO add some more error testing
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),
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='*')
)
)
backup = module.boolean(module.params.get('backup', False))
name = module.params['name']
user = module.params['user']
job = module.params['job']
minute = module.params['minute']
hour = module.params['hour']
day = module.params['day']
month = module.params['month']
weekday = module.params['weekday']
do_install = module.params['state'] == 'present'
changed = False
job = "%s %s %s %s %s %s" % (minute,hour,day,month,weekday,job)
if not user:
user = ""
else:
user = "-u %s" % (user)
rc, out, err, status = (0, 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(user,tmpfile.name)
if rc != 0 and rc != 1: # 1 can mean that there are no jobs.
module.fail_json(msg=err)
backupfile = tempfile.NamedTemporaryFile(prefix='crontab',delete=False)
(rc, out, err) = get_jobs_file(user,backupfile.name)
if rc != 0 and rc != 1:
module.fail_json(msg=err)
old_job = find_job(name,backupfile.name)
if do_install:
if len(old_job) == 0:
(rc, out, err) = add_job(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:
(rc, out, err) = remove_job(name,tmpfile.name)
changed = True
if (rc != 0):
module.fail_json(msg=err)
if changed:
if backup:
module.backup_local(backupfile.name)
(rc, out, err) = install_jobs(user,tmpfile.name)
if (rc != 0):
module.fail_json(msg=err)
jobnames = []
for j in get_jobs(tmpfile.name):
jobnames.append(j[0])
tmpfile.close()
backupfile.close()
if not backup:
module.exit_json(changed=changed,jobs=jobnames)
else:
module.exit_json(changed=changed,jobs=jobnames,backup=backupfile.name)
# include magic from lib/ansible/module_common.py
#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
main()