Task-level params in HITLOperator are merged with DAG params and cannot be hidden in UI

[jgoedeke]

Apache Airflow version

3.1.1

If "Other Airflow 2/3 version" selected, which one?

No response

What happened?

The HITLOperator UI form always shows DAG params. I found no way to hide DAG params for a HITLOperator task.

from airflow.providers.standard.operators.hitl import HITLOperator
from airflow.sdk import dag

dag_params = {
    'dag_param1': 'value1',
    'dag_param2': 'value2',
}

@dag(
    schedule=None,
    params=dag_params,
)
def validate_hitl_operator_params_taskflow():
    HITLOperator(
        task_id='task_without_params',
        subject='Please choose an option:',
        options=['Option A', 'Option B'],
    )

    HITLOperator(
        task_id='task_with_params',
        subject='Please choose an option:',
        options=['Option X', 'Option Y'],
        params={'task_param': 'value'},
    )

validate_hitl_operator_params_taskflow()

What you think should happen instead?

The HITLOperator params should be independent from DAG params. The "Required Action" should only show explicitly specified params.

How to reproduce

Run above provided DAG and go to "Required Actions"

Operating System

docker

Versions of Apache Airflow Providers

No response

Deployment

Docker-Compose

Deployment details

No response

Anything else?

No response

Are you willing to submit PR?

• Yes I am willing to submit a PR!

Code of Conduct

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

[jgoedeke]

Right now this is a problem because of #57350.

If this is the excepted behavior I would appreciate to find this information in the docs e.g. here: https://airflow.apache.org/docs/apache-airflow/stable/tutorial/hitl.html.

[vikramkoka]

@Lee-W Not sure if you are aware of this?

It may make sense to at least document this?

[Lee-W]

I feel it's expected based on our current design but will need to take a deeper look.

[jgoedeke]

For my usecase I do not see any benefit from having the DAG params within every HITLOperator.

I found some more strange behavior:

1. It is not possible to override the value of a DAG param.
2. Param values are not templated, therefore I can not use the DAG param value as default for another field. This is important in case DAG params should not be inserted into HITLOperator params in the future.

    HITLOperator(
        task_id='task_with_more_params',
        subject='Please choose an option:',
        options=['Option X', 'Option Y'],
        params={
            'task_param': 'value',
            'dag_param1': 'This does not override the dag_param1',
            'tempalted_param': '{{ dag_run.conf.get("dag_param2") }}',
        },
    )

If possible I would prefer an optional to include DAG Params in the Operator with a flag like include_dag_params: bool = False.