Source code for system.apache.kafka.example_dag_kafka_message_queue_trigger

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from __future__ import annotations

import json

# [START howto_trigger_message_queue]
from airflow.providers.apache.kafka.triggers.msg_queue import KafkaMessageQueueTrigger
from airflow.providers.standard.operators.empty import EmptyOperator
from airflow.sdk import DAG, Asset, AssetWatcher


def apply_function(message):
    val = json.loads(message.value())
    print(f"Value in message is {val}")
    return True


# Define a trigger that listens to an Apache Kafka message queue
trigger = KafkaMessageQueueTrigger(
    topics=["test"],
    apply_function="example_dag_kafka_message_queue_trigger.apply_function",
    kafka_config_id="kafka_default",
    apply_function_args=None,
    apply_function_kwargs=None,
    poll_timeout=1,
    poll_interval=5,
)

# Define an asset that watches for messages on the queue
asset = Asset("kafka_queue_asset_1", watchers=[AssetWatcher(name="kafka_watcher_1", trigger=trigger)])

with DAG(dag_id="example_kafka_watcher_1", schedule=[asset]) as dag:
    EmptyOperator(task_id="task")
# [END howto_trigger_message_queue]


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)