CloudwatchScheduler

Are you using Rails 4.2+ and ActiveJob with the Shoryuken driver to use SQS? Do you have recurring jobs that you kick off periodically with the amazing Clockwork gem? Tired of paying for a Heroku dyno just to run the clockwork instance? Then CloudwatchScheduler is just the gem for you!

CloudwatchScheduler uses AWS Cloudwatch scheduled event rules to push a message on the cloudwatch_scheduler queue according to the schedule you provide, using a simple DSL similar to the Clockwork DSL you're already familiar with. The rules are free, and the messages cost a few billionths of a cent each, saving you over $25/mo in Heroku dyno costs! Wow!!

And thats not all! It will automatically provision the Cloudwatch Events and Queues via a simple rake task! Amazing!

Installation

Add this line to your application's Gemfile:

gem 'cloudwatch_scheduler'

And then execute:

$ bundle

Or install it yourself as:

$ gem install cloudwatch_scheduler

Usage

Make yourself a config/cloudwatch_scheduler.rb file:

require "cloudwatch_scheduler"

CloudwatchScheduler do |config|

  # 4am every day
  task "spawn_analytics_jobs", cron: "0 4 * * ? *" do
    return if Rails.application.config.deploy_env.sandbox?
    AnalyticsSpawnerJob.perform_later
  end

  task "capture_pg_stats", every: 5.minutes do
    PgHero.capture_query_stats
  end

end

Then do rake cloudwatch_scheduler:setup, and CloudwatchScheduler will provision the events and cloudwatch_scheduler queue. Then, start your Shoruken workers as normal, and the CloudwatchScheduler::Job will get those events, and perform the tasks defined.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/paul/cloudwatch_scheduler.