Default JSON for dag_run.conf in the UI

[JavierLopezT]

Description

It would be nice to be able to define a default JSON that already appears written in the UI. So for instance, you would define in the code something like:

with DAG(blabla) as dag:
    operators
    dag.default_run_conf = '{"date": "2020/01/01", "module": "ff", "serial_number", "123"}'

And in the UI, once you click on Trigger DAG with configuration, this would be there automatically:

Use case/motivation

Saving time. Also, for non-techincal people that trigger DAGs, is more friendly just to fill values than to write a JSON from scratch

Related issues

No response

Are you willing to submit a PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[eladkal]

Isn't this what Params do?
https://airflow.apache.org/docs/apache-airflow/stable/concepts/params.html

[uranusjr]

Yes I think this exactly what Params are supposed to take over for. Maybe we should deprecate dag_run.conf altogether and start pointing people to it, or are there still reasons to prefer conf?

[potiuk]

The only reson why we would like to have params if they do not work with triggering https://airflow.apache.org/docs/apache-airflow/stable/dag-run.html#passing-parameters-when-triggering-dags

I believe (but maybe I am wrong) that we can trigger/backfill tasks only via run_conf override:

https://airflow.apache.org/docs/apache-airflow/stable/configurations-ref.html#dag-run-conf-overrides-params

So we can't deprecate/remove dag_run.conf until we add a mechanism to set params directly I believe (unless I am wrong about it)

[uranusjr]

set params directly

You mean set params when a run is triggered? Currently you can define a param’s default value in the DAG.