GoodJob Cron Idea: Configurable job execution timezones.

[tylerjc]

Hello!

Wasn't sure whether to do this here, or raise an issue. I've never seen this Discussion thing on GitHub before!

Since Rails 6, ActiveJob has been able to honor/propagate the Timezone present when scheduling a job.

I was looking for a way to set up cron definitions so that along with the cron schedule happening in a certain timezone, the execution of the job would also be in that timezone. I had thought doing something like SomeJob.set(timezone: 'America/Chicago').perform_now would work (and then following that line of thinking in the GoodJob cron config adding a timezone param into the set config option). But that isn't the case, sadly.

However, it seems like GoodJob could potentially act as a middleman and utilize that set config, or even just a timezone config under each cronjob definition.

cron: {
  my_job: {
    class: 'MyJob',
    cron: 'every day at 12AM America/Chicago',
    timezone: 'America/Chicago'
    # Could also use use `set` instead, since this will be reflecting the ActiveJob `timezone` param, similar to setting `priority`. 
    # That would allow for a `my_job[:timezone]` config to potentially control the `cron` timezone in the future instead of having
    # to include it (`{ cron: '@midnight'. timezone: 'America/Chicago' }`)
    # set: { timezone: 'America/Chicago' },
  }
},

app/models/good_job/cron_entry.rb

def enqueue(cron_at = nil)
  GoodJob::CurrentThread.within do |current_thread|
    current_thread.cron_key = key
    current_thread.cron_at = cron_at

    configured_job = job_class.constantize.set(set_value)
    I18n.with_locale(I18n.default_locale) do
      Time.use_zone(timezone) do
        kwargs_value.present? ? configured_job.perform_later(*args_value, **kwargs_value) : configured_job.perform_later(*args_value)
      end
    end
  end
rescue ActiveRecord::RecordNotUnique
  false
end

def timezone
  params.fetch(:timezone, Time.zone.name)
end