def get_task_instance(dag_id, task_id, execution_date):
"""Return the task object identified by the given dag_id and task_id."""
dagbag = DagBag()
# Check DAG exists.
if dag_id not in dagbag.dags:
error_message = "Dag id {} not found".format(dag_id)
raise DagNotFound(error_message)
# Get DAG object and check Task Exists
dag = dagbag.get_dag(dag_id)
if not dag.has_task(task_id):
error_message = 'Task {} not found in dag {}'.format(task_id, dag_id)
raise TaskNotFound(error_message)
# Get DagRun object and check that it exists
dagrun = dag.get_dagrun(execution_date=execution_date)
if not dagrun:
error_message = ('Dag Run for date {} not found in dag {}'
.format(execution_date, dag_id))
raise DagRunNotFound(error_message)
# Get task instance object and check that it exists
task_instance = dagrun.get_task_instance(task_id)
if not task_instance:
error_message = ('Task {} instance for date {} not found'
.format(task_id, execution_date))
raise TaskInstanceNotFound(error_message)
return task_instance
def _get_ti(
task: BaseOperator,
exec_date_or_run_id: str,
map_index: int,
*,
create_if_necessary: bool = False,
session: Session = NEW_SESSION,
) -> TaskInstance:
"""Get the task instance through DagRun.run_id, if that fails, get the TI the old way"""
if task.is_mapped:
if map_index < 0:
raise RuntimeError("No map_index passed to mapped task")
elif map_index >= 0:
raise RuntimeError("map_index passed to non-mapped task")
dag_run = _get_dag_run(
dag=task.dag,
exec_date_or_run_id=exec_date_or_run_id,
create_if_necessary=create_if_necessary,
session=session,
)
ti_or_none = dag_run.get_task_instance(task.task_id, map_index=map_index, session=session)
if ti_or_none is None:
if not create_if_necessary:
raise TaskInstanceNotFound(
f"TaskInstance for {task.dag.dag_id}, {task.task_id}, map={map_index} with "
f"run_id or execution_date of {exec_date_or_run_id!r} not found"
)
# TODO: Validate map_index is in range?
ti = TaskInstance(task, run_id=dag_run.run_id, map_index=map_index)
ti.dag_run = dag_run
else:
ti = ti_or_none
ti.refresh_from_task(task)
return ti
def _get_ti(
task: BaseOperator,
exec_date_or_run_id: str,
*,
create_if_necessary: bool = False,
session: Session = NEW_SESSION,
) -> TaskInstance:
"""Get the task instance through DagRun.run_id, if that fails, get the TI the old way"""
dag_run = _get_dag_run(
dag=task.dag,
exec_date_or_run_id=exec_date_or_run_id,
create_if_necessary=create_if_necessary,
session=session,
)
ti_or_none = dag_run.get_task_instance(task.task_id)
if ti_or_none is None:
if not create_if_necessary:
raise TaskInstanceNotFound(
f"TaskInstance for {task.dag.dag_id}, {task.task_id} with "
f"run_id or execution_date of {exec_date_or_run_id!r} not found"
)
ti = TaskInstance(task, run_id=dag_run.run_id)
ti.dag_run = dag_run
else:
ti = ti_or_none
ti.refresh_from_task(task)
return ti
def get_task_instance(dag_id: str, task_id: str, execution_date: datetime) -> TaskInstance:
"""Return the task instance identified by the given dag_id, task_id and execution_date."""
dag = check_and_get_dag(dag_id, task_id)
dagrun = check_and_get_dagrun(dag=dag, execution_date=execution_date)
# Get task instance object and check that it exists
task_instance = dagrun.get_task_instance(task_id)
if not task_instance:
error_message = f'Task {task_id} instance for date {execution_date} not found'
raise TaskInstanceNotFound(error_message)
return task_instance
def get_task_instance(
dag_id, task_id,
execution_date): # type: (str, str, datetime) -> TaskInstance
"""Return the task object identified by the given dag_id and task_id."""
dag = check_and_get_dag(dag_id, task_id)
dagrun = check_and_get_dagrun(dag=dag, execution_date=execution_date)
# Get task instance object and check that it exists
task_instance = dagrun.get_task_instance(task_id)
if not task_instance:
error_message = ('Task {} instance for date {} not found'.format(
task_id, execution_date))
raise TaskInstanceNotFound(error_message)
return task_instance
