whenever/README.rdoc
2010-10-18 18:51:27 -04:00

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== Introduction
Whenever is a Ruby gem that provides a clear syntax for defining cron jobs. It outputs valid cron syntax and can even write your crontab file for you. It is designed to work well with Rails applications and can be deployed with Capistrano. Whenever works fine independently as well.
Ryan Bates created a great Railscast about Whenever: http://railscasts.com/episodes/164-cron-in-ruby
Discussion: http://groups.google.com/group/whenever-gem
== Installation
$ sudo gem install whenever
== Getting started
$ cd /my/rails/app
$ wheneverize .
This will create an initial "config/schedule.rb" file you.
== Example schedule.rb file
every 3.hours do
runner "MyModel.some_process"
rake "my:rake:task"
command "/usr/bin/my_great_command"
end
every 1.day, :at => '4:30 am' do
runner "MyModel.task_to_run_at_four_thirty_in_the_morning"
end
every :hour do # Many shortcuts available: :hour, :day, :month, :year, :reboot
runner "SomeModel.ladeeda"
end
every :sunday, :at => '12pm' do # Use any day of the week or :weekend, :weekday
runner "Task.do_something_great"
end
More examples on the wiki: http://wiki.github.com/javan/whenever/instructions-and-examples
== Define your own job types
Whenever ships with three pre-defined job types: command, runner, and rake. You can define your own with <code>job_type</code>.
For example:
job_type :awesome, '/usr/local/bin/awesome :task :fun_level'
every 2.hours do
awesome "party", :fun_level => "extreme"
end
Would run <code>/usr/local/bin/awesome party extreme</code> every two hours. <code>:task</code> is always replaced with the first argument, and any additional <code>:whatevers</code> are replaced with the options passed in or by variables that have been defined with <code>set</code>.
The default job types that ship with Whenever are defined like so:
job_type :command, ":task"
job_type :runner, "cd :path && script/runner -e :environment ':task'"
job_type :rake, "cd :path && RAILS_ENV=:environment /usr/bin/env rake :task"
If a <code>:path</code> is not set it will default to the directory in which <code>whenever</code> was executed. <code>:environment</code> will default to 'production'.
== Cron output
$ cd /my/rails/app
$ whenever
And you'll see your schedule.rb converted to cron sytax. Note: running `whenever' with no options does not display your current crontab file, it simply shows you the output of converting your schedule.rb file.
== Capistrano integration
Use the built-in Capistrano recipe for easy crontab updates with deploys.
In your "config/deploy.rb" file:
require "whenever/capistrano"
Take a look at the recipe for options you can set. http://github.com/javan/whenever/blob/master/lib/whenever/capistrano.rb
For example, if you're using bundler do this:
set :whenever_command, "bundle exec whenever"
require "whenever/capistrano"
== Credit
Whenever was created for use at Inkling (http://inklingmarkets.com) where I work. Their take on it: http://blog.inklingmarkets.com/2009/02/whenever-easy-way-to-do-cron-jobs-from.html
While building Whenever, I learned a lot by digging through the source code of Capistrano - http://github.com/jamis/capistrano
== Discussion / Feedback / Issues / Bugs
For general discussion and questions, please use the google group: http://groups.google.com/group/whenever-gem
If you've found a genuine bug or issue, please use the Issues section on github: http://github.com/javan/whenever/issues
== License
Copyright (c) 2009+ Javan Makhmali
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.