"""
Cron tasks
==========
This module provides tools to manage periodic tasks using cron.
"""
from __future__ import with_statement
[docs]def add_task(name, timespec, user, command, environment=None):
"""
Add a cron task.
The *command* will be run as *user* periodically.
You can use any valid `crontab(5)`_ *timespec*, including the
``@hourly``, ``@daily``, ``@weekly``, ``@monthly`` and ``@yearly``
shortcuts.
You can also provide an optional dictionary of environment variables
that should be set when running the periodic command.
Examples::
from fabtools.cron import add_task
# Run every month
add_task('cleanup', '@monthly', 'alice', '/home/alice/bin/cleanup.sh')
# Run every tuesday and friday at 5:30am
add_task('reindex', '30 5 * * 2,4', 'bob', '/home/bob/bin/reindex.sh')
.. _crontab(5): http://manpages.debian.net/cgi-bin/man.cgi?query=crontab&sektion=5
"""
if environment is None:
environment = {}
lines = []
# Write optional environment variables first
for key, value in environment.iteritems():
lines.append('%(key)s=%(value)s\n' % locals())
# Write the main crontab line
lines.append('%(timespec)s %(user)s %(command)s\n' % locals())
from fabtools.require.files import file as require_file
require_file(
path='/etc/cron.d/%(name)s' % locals(),
contents=''.join(lines),
owner='root',
mode='0644',
use_sudo=True,
)
[docs]def add_daily(name, user, command, environment=None):
"""
Shortcut to add a daily cron task.
Example::
import fabtools
# Run every day
fabtools.cron.add_daily('backup', 'root', '/usr/local/bin/backup.sh')
"""
add_task(name, '@daily', user, command, environment)