REST API array of strings

[johnhoran]

I'm trying to figure out how to use arrays in the rest interface. Specifically I want to get dags that are failed or queued. According to the REST documentation state can be an array of strings, but I'm not sure how to actually format that
https://airflow.apache.org/docs/apache-airflow/3.2.1/stable-rest-api-ref.html#operation/get_dag_runs

In airflow 2 https://<airflow>/api/v1/dags/~/dagRuns?state=failed%2Cqueued would give a list of all queued or failed dags, but in airflow 3 a call to https://<airflow>/api/v2/dags/~/dagRuns?state=failed%2Cqueued returns a message saying "Invalid value for state. Valid values are queued, running, success, failed"

[parkhojeong]

@johnhoran
Thanks for the report. This is a behavior change between the Airflow 2 /api/v1 endpoint and the Airflow 3 /api/v2 endpoint.

In Airflow 3, state is handled as an array query parameter. Multiple values should be sent by repeating the query parameter, for example: /api/v2/dags/~/dagRuns?state=failed&state=queued

The old Airflow 2 form: /api/v2/dags/~/dagRuns?state=failed%2Cqueued is decoded as a single value, failed,queued, and then rejected because it is not one of the valid individual DagRun states: queued, running, success, or failed.

So for Airflow 3 API v2, please use repeated state parameters instead of a comma-separated value. state=failed&state=queued not state=failed%2Cqueued

implemantation(airflow-core/src/airflow/api_fastapi/common/parameters.py:1143)

def _transform_dag_run_states(states: Iterable[str] | None) -> list[DagRunState | None] | None:
    try:
        if not states:
            return None
        return [None if s in ("none", None) else DagRunState(s) for s in states]
    except ValueError:
        raise HTTPException(
            status_code=HTTP_422_UNPROCESSABLE_CONTENT,
            detail=f"Invalid value for state. Valid values are {', '.join(DagRunState)}",
        )