Source code for airflow.operators.latest_only

# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
This module contains an operator to run downstream tasks only for the
latest scheduled DagRun
from __future__ import annotations

from typing import TYPE_CHECKING, Iterable

import pendulum

from airflow.operators.branch import BaseBranchOperator
from airflow.utils.context import Context

    from airflow.models import DAG, DagRun

[docs]class LatestOnlyOperator(BaseBranchOperator): """ Allows a workflow to skip tasks that are not running during the most recent schedule interval. If the task is run outside of the latest schedule interval (i.e. external_trigger), all directly downstream tasks will be skipped. Note that downstream tasks are never skipped if the given DAG_Run is marked as externally triggered. """
[docs] ui_color = '#e9ffdb' # nyanza
[docs] def choose_branch(self, context: Context) -> str | Iterable[str]: # If the DAG Run is externally triggered, then return without # skipping downstream tasks dag_run: DagRun = context["dag_run"] if dag_run.external_trigger:"Externally triggered DAG_Run: allowing execution to proceed.") return list(context['task'].get_direct_relative_ids(upstream=False)) dag: DAG = context["dag"] next_info = dag.next_dagrun_info(dag.get_run_data_interval(dag_run), restricted=False) now ='UTC') if next_info is None:"Last scheduled execution: allowing execution to proceed.") return list(context['task'].get_direct_relative_ids(upstream=False)) left_window, right_window = next_info.data_interval 'Checking latest only with left_window: %s right_window: %s now: %s', left_window, right_window, now, ) if not left_window < now <= right_window:'Not latest execution, skipping downstream.') # we return an empty list, thus the parent BaseBranchOperator # won't exclude any downstream tasks from skipping. return [] else:'Latest, allowing execution to proceed.') return list(context['task'].get_direct_relative_ids(upstream=False))

Was this entry helpful?