providers/google/docs/operators/cloud/pubsub.rst
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Google Cloud PubSub <https://cloud.google.com/pubsub/>__ is a fully-managed real-time
messaging service that allows you to send and receive messages between independent applications.
You can leverage Cloud Pub/Sub's flexibility to decouple systems and components hosted
on Google Cloud or elsewhere on the Internet.
Publisher applications can send messages to a topic and other applications can subscribe to that topic to receive the messages. By decoupling senders and receivers Google Cloud PubSub allows developers to communicate between independently written applications.
Prerequisite Tasks ^^^^^^^^^^^^^^^^^^
.. include:: /operators/_partials/prerequisite_tasks.rst
.. _howto/operator:PubSubCreateTopicOperator:
Creating a PubSub topic ^^^^^^^^^^^^^^^^^^^^^^^
The PubSub topic is a named resource to which messages are sent by publishers.
The :class:~airflow.providers.google.cloud.operators.pubsub.PubSubCreateTopicOperator operator creates a topic.
.. exampleinclude:: /../../google/tests/system/google/cloud/pubsub/example_pubsub.py :language: python :start-after: [START howto_operator_gcp_pubsub_create_topic] :end-before: [END howto_operator_gcp_pubsub_create_topic]
.. _howto/operator:PubSubCreateSubscriptionOperator:
Creating a PubSub subscription ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
A Subscription is a named resource representing the stream of messages from a single, specific topic,
to be delivered to the subscribing application.
The :class:~airflow.providers.google.cloud.operators.pubsub.PubSubCreateSubscriptionOperator operator creates the subscription.
.. exampleinclude:: /../../google/tests/system/google/cloud/pubsub/example_pubsub.py :language: python :start-after: [START howto_operator_gcp_pubsub_create_subscription] :end-before: [END howto_operator_gcp_pubsub_create_subscription]
.. _howto/operator:PubSubPublishMessageOperator:
Publishing PubSub messages ^^^^^^^^^^^^^^^^^^^^^^^^^^
A Message is a combination of data and (optional) attributes that a publisher sends to a topic and is eventually delivered to subscribers.
The :class:~airflow.providers.google.cloud.operators.pubsub.PubSubPublishMessageOperator operator would publish messages.
.. exampleinclude:: /../../google/tests/system/google/cloud/pubsub/example_pubsub.py :language: python :start-after: [START howto_operator_gcp_pubsub_publish] :end-before: [END howto_operator_gcp_pubsub_publish]
.. _howto/operator:PubSubPullSensor:
Pulling messages from a PubSub subscription
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The :class:~airflow.providers.google.cloud.sensors.pubsub.PubSubPullSensor sensor pulls messages from a PubSub subscription
and pass them through XCom.
.. exampleinclude:: /../../google/tests/system/google/cloud/pubsub/example_pubsub.py :language: python :start-after: [START howto_operator_gcp_pubsub_pull_message_with_sensor] :end-before: [END howto_operator_gcp_pubsub_pull_message_with_sensor]
Also for this action you can use sensor in the deferrable mode:
.. exampleinclude:: /../../google/tests/system/google/cloud/pubsub/example_pubsub_deferrable.py :language: python :dedent: 4 :start-after: [START howto_operator_gcp_pubsub_pull_message_with_async_sensor] :end-before: [END howto_operator_gcp_pubsub_pull_message_with_async_sensor]
.. exampleinclude:: /../../google/tests/system/google/cloud/pubsub/example_pubsub.py :language: python :start-after: [START howto_operator_gcp_pubsub_pull_message_with_operator] :end-before: [END howto_operator_gcp_pubsub_pull_message_with_operator]
To pull messages from XCom use the :class:~airflow.providers.standard.operators.bash.BashOperator.
.. exampleinclude:: /../../google/tests/system/google/cloud/pubsub/example_pubsub.py :language: python :start-after: [START howto_operator_gcp_pubsub_pull_messages_result_cmd] :end-before: [END howto_operator_gcp_pubsub_pull_messages_result_cmd]
.. exampleinclude:: /../../google/tests/system/google/cloud/pubsub/example_pubsub.py :language: python :start-after: [START howto_operator_gcp_pubsub_pull_messages_result] :end-before: [END howto_operator_gcp_pubsub_pull_messages_result]
.. _howto/operator:PubSubDeleteSubscriptionOperator:
Deleting a PubSub subscription ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The :class:~airflow.providers.google.cloud.operators.pubsub.PubSubDeleteSubscriptionOperator operator deletes the subscription.
.. exampleinclude:: /../../google/tests/system/google/cloud/pubsub/example_pubsub.py :language: python :start-after: [START howto_operator_gcp_pubsub_unsubscribe] :end-before: [END howto_operator_gcp_pubsub_unsubscribe]
.. _howto/operator:PubSubDeleteTopicOperator:
Deleting a PubSub topic ^^^^^^^^^^^^^^^^^^^^^^^
The :class:~airflow.providers.google.cloud.operators.pubsub.PubSubDeleteTopicOperator operator deletes topic.
.. exampleinclude:: /../../google/tests/system/google/cloud/pubsub/example_pubsub.py :language: python :start-after: [START howto_operator_gcp_pubsub_delete_topic] :end-before: [END howto_operator_gcp_pubsub_delete_topic]
Reference ^^^^^^^^^
For further information, look at:
Client Library Documentation <https://googleapis.dev/python/pubsub/latest/index.html>__Product Documentation <https://cloud.google.com/pubsub/docs/>__