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"""
Example DAG for demonstrating the behavior of the AssetAlias feature in Airflow, including conditional and
asset expression-based scheduling.
Notes on usage:
Turn on all the DAGs.
Before running any DAG, the schedule of the "asset_alias_example_alias_consumer_with_no_taskflow" DAG will show as "unresolved AssetAlias".
This is expected because the asset alias has not been resolved into any asset yet.
Once the "asset_s3_bucket_producer_with_no_taskflow" DAG is triggered, the "asset_s3_bucket_consumer_with_no_taskflow" DAG should be triggered upon completion.
This is because the asset alias "example-alias-no-taskflow" is used to add an asset event to the asset "s3://bucket/my-task-with-no-taskflow"
during the "produce_asset_events_through_asset_alias_with_no_taskflow" task. Also, the schedule of the "asset_alias_example_alias_consumer_with_no_taskflow" DAG should change to "Asset" as
the asset alias "example-alias-no-taskflow" is now resolved to the asset "s3://bucket/my-task-with-no-taskflow" and this DAG should also be triggered.
"""
from __future__ import annotations
import pendulum
from airflow import DAG
from airflow.providers.standard.operators.python import PythonOperator
from airflow.sdk.definitions.asset import Asset, AssetAlias
with DAG(
dag_id="asset_s3_bucket_producer_with_no_taskflow",
start_date=pendulum.datetime(2021, 1, 1, tz="UTC"),
schedule=None,
catchup=False,
tags=["producer", "asset"],
):
[docs] def produce_asset_events():
pass
PythonOperator(
task_id="produce_asset_events",
outlets=[Asset("s3://bucket/my-task-with-no-taskflow")],
python_callable=produce_asset_events,
)
with DAG(
dag_id="asset_alias_example_alias_producer_with_no_taskflow",
start_date=pendulum.datetime(2021, 1, 1, tz="UTC"),
schedule=None,
catchup=False,
tags=["producer", "asset-alias"],
):
[docs] def produce_asset_events_through_asset_alias_with_no_taskflow(*, outlet_events=None):
bucket_name = "bucket"
object_path = "my-task"
outlet_events[AssetAlias("example-alias-no-taskflow")].add(Asset(f"s3://{bucket_name}/{object_path}"))
PythonOperator(
task_id="produce_asset_events_through_asset_alias_with_no_taskflow",
outlets=[AssetAlias("example-alias-no-taskflow")],
python_callable=produce_asset_events_through_asset_alias_with_no_taskflow,
)
with DAG(
dag_id="asset_s3_bucket_consumer_with_no_taskflow",
start_date=pendulum.datetime(2021, 1, 1, tz="UTC"),
schedule=[Asset("s3://bucket/my-task-with-no-taskflow")],
catchup=False,
tags=["consumer", "asset"],
):
[docs] def consume_asset_event():
pass
PythonOperator(task_id="consume_asset_event", python_callable=consume_asset_event)
with DAG(
dag_id="asset_alias_example_alias_consumer_with_no_taskflow",
start_date=pendulum.datetime(2021, 1, 1, tz="UTC"),
schedule=[AssetAlias("example-alias-no-taskflow")],
catchup=False,
tags=["consumer", "asset-alias"],
):
[docs] def consume_asset_event_from_asset_alias(*, inlet_events=None):
for event in inlet_events[AssetAlias("example-alias-no-taskflow")]:
print(event)
PythonOperator(
task_id="consume_asset_event_from_asset_alias",
python_callable=consume_asset_event_from_asset_alias,
inlets=[AssetAlias("example-alias-no-taskflow")],
)