.. 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 .. http://www.apache.org/licenses/LICENSE-2.0 .. Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. Macros reference ================ Variables and macros can be used in templates (see the :ref:`jinja-templating` section) The following come for free out of the box with Airflow. Additional custom macros can be added globally through :ref:`plugins`, or at a DAG level through the ``DAG.user_defined_macros`` argument. Default Variables ----------------- The Airflow engine passes a few variables by default that are accessible in all templates ===================================== ==================================== Variable Description ===================================== ==================================== ``{{ ds }}`` the execution date as ``YYYY-MM-DD`` ``{{ ds_nodash }}`` the execution date as ``YYYYMMDD`` ``{{ prev_ds }}`` the previous execution date as ``YYYY-MM-DD`` if ``{{ ds }}`` is ``2018-01-08`` and ``schedule_interval`` is ``@weekly``, ``{{ prev_ds }}`` will be ``2018-01-01`` ``{{ prev_ds_nodash }}`` the previous execution date as ``YYYYMMDD`` if exists, else ``None`` ``{{ next_ds }}`` the next execution date as ``YYYY-MM-DD`` if ``{{ ds }}`` is ``2018-01-01`` and ``schedule_interval`` is ``@weekly``, ``{{ next_ds }}`` will be ``2018-01-08`` ``{{ next_ds_nodash }}`` the next execution date as ``YYYYMMDD`` if exists, else ``None`` ``{{ yesterday_ds }}`` the day before the execution date as ``YYYY-MM-DD`` ``{{ yesterday_ds_nodash }}`` the day before the execution date as ``YYYYMMDD`` ``{{ tomorrow_ds }}`` the day after the execution date as ``YYYY-MM-DD`` ``{{ tomorrow_ds_nodash }}`` the day after the execution date as ``YYYYMMDD`` ``{{ ts }}`` same as ``execution_date.isoformat()``. Example: ``2018-01-01T00:00:00+00:00`` ``{{ ts_nodash }}`` same as ``ts`` without ``-``, ``:`` and TimeZone info. Example: ``20180101T000000`` ``{{ ts_nodash_with_tz }}`` same as ``ts`` without ``-`` and ``:``. Example: ``20180101T000000+0000`` ``{{ execution_date }}`` the execution_date (`pendulum.Pendulum`_) ``{{ prev_execution_date }}`` the previous execution date (if available) (`pendulum.Pendulum`_) ``{{ prev_execution_date_success }}`` execution date from prior succesful dag run (if available) (`pendulum.Pendulum`_) ``{{ prev_start_date_success }}`` start date from prior successful dag run (if available) (`pendulum.Pendulum`_) ``{{ next_execution_date }}`` the next execution date (`pendulum.Pendulum`_) ``{{ dag }}`` the DAG object ``{{ task }}`` the Task object ``{{ macros }}`` a reference to the macros package, described below ``{{ task_instance }}`` the task_instance object ``{{ end_date }}`` same as ``{{ ds }}`` ``{{ latest_date }}`` same as ``{{ ds }}`` ``{{ ti }}`` same as ``{{ task_instance }}`` ``{{ params }}`` a reference to the user-defined params dictionary which can be overridden by the dictionary passed through ``trigger_dag -c`` if you enabled ``dag_run_conf_overrides_params` in ``airflow.cfg`` ``{{ var.value.my_var }}`` global defined variables represented as a dictionary ``{{ var.json.my_var.path }}`` global defined variables represented as a dictionary with deserialized JSON object, append the path to the key within the JSON object ``{{ task_instance_key_str }}`` a unique, human-readable key to the task instance formatted ``{dag_id}_{task_id}_{ds}`` ``{{ conf }}`` the full configuration object located at ``airflow.configuration.conf`` which represents the content of your ``airflow.cfg`` ``{{ run_id }}`` the ``run_id`` of the current DAG run ``{{ dag_run }}`` a reference to the DagRun object ``{{ test_mode }}`` whether the task instance was called using the CLI's test subcommand ===================================== ==================================== Note that you can access the object's attributes and methods with simple dot notation. Here are some examples of what is possible: ``{{ task.owner }}``, ``{{ task.task_id }}``, ``{{ ti.hostname }}``, ... Refer to the models documentation for more information on the objects' attributes and methods. The ``var`` template variable allows you to access variables defined in Airflow's UI. You can access them as either plain-text or JSON. If you use JSON, you are also able to walk nested structures, such as dictionaries like: ``{{ var.json.my_dict_var.key1 }}`` Macros ------ Macros are a way to expose objects to your templates and live under the ``macros`` namespace in your templates. A few commonly used libraries and methods are made available. ================================= ============================================== Variable Description ================================= ============================================== ``macros.datetime`` The standard lib's :class:`datetime.datetime` ``macros.timedelta`` The standard lib's :class:`datetime.timedelta` ``macros.dateutil`` A reference to the ``dateutil`` package ``macros.time`` The standard lib's :class:`datetime.time` ``macros.uuid`` The standard lib's :mod:`uuid` ``macros.random`` The standard lib's :mod:`random` ================================= ============================================== Some airflow specific macros are also defined: .. automodule:: airflow.macros :show-inheritance: :members: .. autofunction:: airflow.macros.hive.closest_ds_partition .. autofunction:: airflow.macros.hive.max_partition .. _pendulum.Pendulum: https://pendulum.eustace.io/docs/1.x/#introduction