Source code for system.google.cloud.pubsub.example_pubsub_deferrable

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"""
Example Airflow DAG that uses Google PubSub services.
"""

from __future__ import annotations

import os
from datetime import datetime

from airflow.models.dag import DAG
from airflow.providers.google.cloud.operators.pubsub import (
    PubSubCreateSubscriptionOperator,
    PubSubCreateTopicOperator,
    PubSubDeleteSubscriptionOperator,
    PubSubDeleteTopicOperator,
    PubSubPublishMessageOperator,
)
from airflow.providers.google.cloud.sensors.pubsub import PubSubPullSensor

try:
    from airflow.sdk import TriggerRule
except ImportError:
    # Compatibility for Airflow < 3.1
    from airflow.utils.trigger_rule import TriggerRule  # type: ignore[no-redef,attr-defined]

ENV_ID = os.environ.get("SYSTEM_TESTS_ENV_ID", "default")
PROJECT_ID = os.environ.get("SYSTEM_TESTS_GCP_PROJECT", "default")

DAG_ID = "pubsub_async"

TOPIC_ID = f"topic-{DAG_ID}-{ENV_ID}"
MESSAGE = {"data": b"Tool", "attributes": {"name": "wrench", "mass": "1.3kg", "count": "3"}}


with DAG(
    DAG_ID,
    schedule="@once",  # Override to match your needs
    start_date=datetime(2021, 1, 1),
    catchup=False,
) as dag:
    create_topic = PubSubCreateTopicOperator(
        task_id="create_topic", topic=TOPIC_ID, project_id=PROJECT_ID, fail_if_exists=False
    )

    subscribe_task = PubSubCreateSubscriptionOperator(
        task_id="subscribe_task", project_id=PROJECT_ID, topic=TOPIC_ID
    )

    publish_task = PubSubPublishMessageOperator(
        task_id="publish_task",
        project_id=PROJECT_ID,
        topic=TOPIC_ID,
        messages=[MESSAGE, MESSAGE],
    )
    subscription = subscribe_task.output

    # [START howto_operator_gcp_pubsub_pull_message_with_async_sensor]
    pull_messages_async = PubSubPullSensor(
        task_id="pull_messages_async",
        ack_messages=True,
        project_id=PROJECT_ID,
        subscription=subscription,
        deferrable=True,
        return_immediately=False,
    )
    # [END howto_operator_gcp_pubsub_pull_message_with_async_sensor]

    unsubscribe_task = PubSubDeleteSubscriptionOperator(
        task_id="unsubscribe_task",
        project_id=PROJECT_ID,
        subscription=subscription,
    )
    unsubscribe_task.trigger_rule = TriggerRule.ALL_DONE

    delete_topic = PubSubDeleteTopicOperator(task_id="delete_topic", topic=TOPIC_ID, project_id=PROJECT_ID)
    delete_topic.trigger_rule = TriggerRule.ALL_DONE

    (
        create_topic
        >> subscribe_task
        >> publish_task
        >> pull_messages_async
        >> unsubscribe_task
        >> delete_topic
    )

    # Task dependencies created via `XComArgs`:
    #   subscribe_task >> pull_messages_async
    #   subscribe_task >> unsubscribe_task

    # ### Everything below this line is not part of example ###
    # ### Just for system tests purpose ###
    from tests_common.test_utils.watcher import watcher

    # This test needs watcher in order to properly mark success/failure
    # when "tearDown" task with trigger rule is part of the DAG
    list(dag.tasks) >> watcher()


from tests_common.test_utils.system_tests import get_test_run  # noqa: E402

# Needed to run the example DAG with pytest (see: contributing-docs/testing/system_tests.rst)
test_run = get_test_run(dag)