how do i set up cron jobs with rails?

Question

Hi,

I have to implement a fairly database intensive task periodically. I am using rails for the application to which this task is related and thus for the sake of easiness and uniqueness in approach I want to know how can I best implement cron job with rails. I am aware that rake is one solution, but am totally unaware of how to use it.

Thanks.

Answer 1

javan-whenever is another good thing to look at.

http://github.com/javan/whenever

Answer 2

rubber, a Capistrano plugin for cloud deployment, provides a set of helper scripts for managing cron jobs. These scripts will work completely independently of rubber, however.

If you grab the "cron-rake", "cron-runner", and "cron-sh" scripts from http://github.com/wr0ngway/rubber/tree/master/lib/generators/vulcanize/templates/base/script/ and place them in the script/ directory of your Rails project, you should be good to go. Don't forget to make them executable.

Most of the real work is done in "cron-sh." "cron-rake" is a convenience wrapper for running rake tasks. "cron-runner" is a convenience wrapper for running arbitrary Ruby (much like script/runner provides).

Answer 3

Just implement your script to do whatever it is you need, and then invoke it with script/runner from a cron job.

0 * * * * cd /path/to_your/app && RAILS_ENV=production script/runner scripts/my_maintenance_script.rb

That'll kick off my_maintenance_script.rb in the context of your production environment once per hour. Pretty bare-metal, but it'll get the job done.

Answer 4

delayed_job is good, it stores the details of the job in the database.