Feature request : Make the startDate/nextDate of a job available to a job.

[vineethvarghese]

We are planning to use Chronos at our organization but see some gaps in what we want and what is available in Chronos today. While the title of this issue is to address a feature we need immediately, I will list down all that we are looking for.

Our use-case requires us to run jobs on all dates that satisfies the schedule of ScheduledJob. In other words, we don't want to skip date just because it is in the past. This is because the dates are used to pull slices of data from systems onto Hadoop. In the current form of Chronos, we can't enable/configure this to be so. This would also require the startDate/newDate/intendedRunDate of a job to be available as metadata to jobs (env var?). We could start off by making the startDate available as an environment variable to jobs. This seems possible in MesosTaskBuilder as the startDate is embedded in the taskId.

In general, it would be great if we could structure the code in a way so that the job scheduling mechanism can be extended easily. What are your thoughts?

[gkleiman]

Fixed by #629