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**Description**

Airflow 1.10 support providing a run_id to TriggerDagRunOperator using [DagRunOrder](https://github.com/apache/airflow/blob/v1-10-stable/airflow/operators/dagrun_operator.py#L30-L33) object that will be returned after calling [TriggerDagRunOperator#python_callable](https://github.com/apache/airflow/blob/v1-10-stable/airflow/operators/dagrun_operator.py#L88-L95). With https://github.com/apache/airflow/pull/6317 (Airflow 2.0), this behavior changed and one could not provide run_id anymore to the triggered dag, which is very odd to say the least.

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**Use case / motivation**

I want to be able to provide run_id for the TriggerDagRunOperator. In my case, I use the TriggerDagRunOperator to trigger 30K dag_run daily and will be so annoying to see them having unidentifiable run_id.

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After discussing with @ashb
**Suggested fixes can be**
 * provide a templated run_id as a parameter to TriggerDagRunOperator.
 * restore the old behavior of Airflow 1.10, where DagRunOrder holds the run_id and dag_run_conf of the triggered dag
 * create a new sub-class of TriggerDagRunOperator to fully customize it

**Are you willing to submit a PR?**

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**Related Issues**

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airflow/operators/trigger_dagrun.py
if self.reset_dag_run:
                self.log.info("Clearing %s on %s", self.trigger_dag_id, self.execution_date)
                
                dag_model = DagModel.get_current(self.trigger_dag_id)
                if dag_model is None:
                    raise DagNotFound(f"Dag id {self.trigger_dag_id} not found in DagModel")
                dag_bag = DagBag(dag_folder=dag_model.fileloc, read_dags_from_db=True)
                dag = dag_bag.get_dag(self.trigger_dag_id)
                dag.clear(start_date=self.execution_date, end_date=self.execution_date)
                dag_run = DagRun.find(dag_id=dag.dag_id, run_id=run_id)[0]
            else:
                raise e
        if self.wait_for_completion:
            
            while True:
                self.log.info(
                    'Waiting for %s on %s to become allowed state %s ...',
                    self.trigger_dag_id,
                    dag_run.execution_date,
                    self.allowed_states,
                )
                time.sleep(self.poke_interval)
                dag_run.refresh_from_db()
                state = dag_run.state
                if state in self.failed_states:
                    raise AirflowException(f"{self.trigger_dag_id} failed with failed states {state}")
                if state in self.allowed_states:
                    self.log.info("%s finished with allowed state %s", self.trigger_dag_id, state)
                    return