Whenever is a ruby gem that provides a ruby syntax for defining cron jobs. It was designed to work well with Rails applications, but can be used independently as well.
To install Whenever in a Rails (2.1 or greater) application:
in your “config/environment.rb” file:
Rails::Initializer.run do |config| config.gem 'javan-whenever', :lib => 'whenever', :source => 'http://gems.github.com' end
To install this gem (and all other missing gem dependencies), run rake gems:install (use sudo if necessary).
In older versions of Rails:
$ gem sources -a gems.github.com $ gem install whenever
in your “config/environment.rb” file:
Rails::Initializer.run do |config| ... end require "whenever"
$ cd /my/rails/app $ wheneverize .
This will create an initial “config/schedule.rb” file you.
set :runner_path, '/var/www/apps/my_app' # Whenever will try to use your RAILS_ROOT if this isn't set set :runner_environment, :production # Whenever defaults to production so only set this if you want to use a different environment. set :cron_log, '/path/to/my/cronlog.log' # Where to log (this should NOT be your Rails log) every 2.hours do runner "MyModel.some_process" # runners are the script/runners you know and love command "/usr/local/bin/my_great_command" # commands are any unix command end every 1.day, :at => '4:30 am' do # If not :at option is set these jobs will run at midnight runner "DB.Backup", :cron_log => false # You can specify false for no logging or a string a different log file to override logging. end every :hour do # Many shortcuts available: :hour, :day, :month, :year, :reboot runner "SomeModel.ladeda" end every :sunday do # Use any day of the week or :weekend, :weekday runner "Task.do_something_great" end
$ cd /my/rails/app $ whenever
And you’ll see your schedule.rb converted to cron sytax
Use the “whenever:write_cron” task to automatically write your crontab file with each deploy.
in your “config/deploy.rb” file do something like:
after "deploy:symlink", "whenever:write_cron"
THIS WILL COMPLETELY OVERWRITE ANY EXISTING CRONTAB ENTRIES!
Better documentation on the way!