We have a DAG, call it A, which runs. When this DAG is finished we would like to have another DAG, call it B, triggered. We have gotten that to work with ExternalTaskSensor, but is there a way for B to read any of the xcom values from A?
I have tried to use
{{ task_instance.xcom_pull(dag_id='a dag_id', task_ids='a task_id', key='a key') }}
but that returns None, so I guess that is only meant to be used between tasks in the same DAG.