allow custom run_id

[waleedsamy]

With apache/airflow#6317, TriggerDagRunOperator changed to drop the use of DagRunOrder and you thankfully adapted their way. However I think we are following bad decision by allowing TriggerMultiDagRunOperator to use unidentifiable run_id

I'd like to discuss the possibility of restoring the old behavior where TriggerMultiDagRunOperator#python_callable can return DagRunOrder, so a user can provide custom+dynamic run_id.

In my case, I use TriggerMultiDagRunOperator to trigger thousands of dagruns and I assign for every one of those an identifiable run_id that can distinguish every dagrun from the other. surrendering indefinable run_id with gabbrish one is not wise at all.
WDYT?

[waleedsamy]

Created an airflow issue apache/airflow#17438

[mastak]

Hi @waleedsamy
Added it in the new version 2.2.0. Here you can find an example:
https://github.com/mastak/airflow_multi_dagrun/blob/v2.2.0/examples/trigger_with_custom_trigger_id.py#L12

Be careful, run_id has to be unique.