Variables, macros and filters can be used in templates (see the :ref:`concepts:jinja-templating` section)
The following come for free out of the box with Airflow.
Additional custom macros can be added globally through :doc:`authoring-and-scheduling/plugins`, or at a DAG level through the
DAG.user_defined_macros argument.
The Airflow engine passes a few variables by default that are accessible in all templates
| Variable | Type | Description |
|---|---|---|
{{ data_interval_start }} |
pendulum.DateTime | Start of the data interval. Added in version 2.3. |
{{ data_interval_end }} |
pendulum.DateTime | End of the data interval. Added in version 2.3. |
{{ ds }} |
str | The DAG run's logical date as
YYYY-MM-DD.Same as
{{ dag_run.logical_date | ds }}. |
{{ ds_nodash }} |
str | Same as {{ dag_run.logical_date | ds_nodash }}. |
{{ ts }} |
str | Same as
{{ dag_run.logical_date | ts }}.Example:
2018-01-01T00:00:00+00:00. |
{{ ts_nodash_with_tz }} |
str | Same as
{{ dag_run.logical_date | ts_nodash_with_tz }}.Example:
20180101T000000+0000. |
{{ ts_nodash }} |
str | Same as
{{ dag_run.logical_date | ts_nodash }}.Example:
20180101T000000. |
{{ prev_data_interval_start_success }} |
pendulum.DateTime
| None |
Start of the data interval of the prior successful DAG run.
Added in version 2.3.
|
{{ prev_data_interval_end_success }} |
pendulum.DateTime
| None |
End of the data interval of the prior successful DAG run.
Added in version 2.3.
|
{{ prev_start_date_success }} |
pendulum.DateTime
| None |
Start date from prior successful DAG run (if available). |
{{ dag }} |
DAG | The currently running DAG. |
{{ task }} |
BaseOperator | The currently running task.
|
{{ macros }} |
A reference to the macros package. See Macros below.
|
|
{{ task_instance }} |
TaskInstance | The currently running task instance. |
{{ ti }} |
TaskInstance | Same as {{ task_instance }}. |
{{ params }} |
dict[str, Any] | The user-defined params. This can be overridden by the mapping
passed to
trigger_dag -c if dag_run_conf_overrides_paramsis enabled in
airflow.cfg. |
{{ var.value }} |
Airflow variables. See Airflow Variables in Templates below. | |
{{ var.json }} |
Airflow variables. See Airflow Variables in Templates below. | |
{{ conn }} |
Airflow connections. See Airflow Connections in Templates below. | |
{{ task_instance_key_str }} |
str | A unique, human-readable key to the task instance. The format is
{dag_id}__{task_id}__{ds_nodash}. |
{{ conf }} |
AirflowConfigParser | The full configuration object representing the content of your
airflow.cfg. See :mod:`airflow.configuration.conf`. |
{{ run_id }} |
str | The currently running DAG run's run ID. |
{{ dag_run }} |
DagRun | The currently running DAG run. |
{{ test_mode }} |
bool | Whether the task instance was run by the airflow test CLI. |
{{ expanded_ti_count }} |
int | None |
Number of task instances that a mapped task was expanded into. If
the current task is not mapped, this should be
None.Added in version 2.5.
|
Note
The DAG run's logical date, and values derived from it, such as ds and
ts, should not be considered unique in a DAG. Use run_id instead.
The following variables are deprecated. They are kept for backward compatibility, but you should convert existing code to use other variables instead.
| Deprecated Variable | Description |
|---|---|
{{ execution_date }} |
the execution date (logical date), same as dag_run.logical_date |
{{ next_execution_date }} |
the logical date of the next scheduled run (if applicable);
you may be able to use data_interval_end instead |
{{ next_ds }} |
the next execution date as YYYY-MM-DD if exists, else None |
{{ next_ds_nodash }} |
the next execution date as YYYYMMDD if exists, else None |
{{ prev_execution_date }} |
the logical date of the previous scheduled run (if applicable) |
{{ prev_ds }} |
the previous execution date as YYYY-MM-DD if exists, else None |
{{ prev_ds_nodash }} |
the previous 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 |
{{ prev_execution_date_success }} |
execution date from prior successful DAG run |
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 Airflow Variables.
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 }}.
It is also possible to fetch a variable by string if needed with
{{ var.value.get('my.var', 'fallback') }} or
{{ var.json.get('my.dict.var', {'key1': 'val1'}) }}. Defaults can be
supplied in case the variable does not exist.
Similarly, Airflow Connections data can be accessed via the conn template variable. For example, you could use expressions in your templates like {{ conn.my_conn_id.login }},
{{ conn.my_conn_id.password }}, etc.
Just like with var it's possible to fetch a connection by string (e.g. {{ conn.get('my_conn_id_'+index).host }}
) or provide defaults (e.g {{ conn.get('my_conn_id', {"host": "host1", "login": "user1"}).host }}).
Additionally, the extras field of a connection can be fetched as a Python Dictionary with the extra_dejson field, e.g.
conn.my_aws_conn_id.extra_dejson.region_name would fetch region_name out of extras.
Airflow defines some Jinja filters that can be used to format values.
For example, using {{ execution_date | ds }} will output the execution_date in the YYYY-MM-DD format.
| Filter | Operates on | Description |
|---|---|---|
ds |
datetime | Format the datetime as YYYY-MM-DD |
ds_nodash |
datetime | Format the datetime as YYYYMMDD |
ts |
datetime | Same as .isoformat(), Example: 2018-01-01T00:00:00+00:00 |
ts_nodash |
datetime | Same as ts filter without -, : or TimeZone info.
Example: 20180101T000000 |
ts_nodash_with_tz |
datetime | As ts filter without - or :. Example
20180101T000000+0000 |
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 :mod:`time` |
macros.uuid |
The standard lib's :mod:`uuid` |
macros.random |
The standard lib's :class:`random.random` |
Some airflow specific macros are also defined:
.. automodule:: airflow.macros
:members: