Add How To Guide for Dataflow (#13461)

airflow/providers/google/cloud/example_dags/example_dataflow.py

@@ -65,7 +65,7 @@
     tags=['example'],
 ) as dag_native_java:
 
-    # [START howto_operator_start_java_job]
+    # [START howto_operator_start_java_job_jar_on_gcs]
     start_java_job = DataflowCreateJavaJobOperator(
         task_id="start-java-job",
         jar=GCS_JAR,
@@ -78,8 +78,9 @@
         check_if_running=CheckJobRunning.IgnoreJob,
         location='europe-west3',
     )
-    # [END howto_operator_start_java_job]
+    # [END howto_operator_start_java_job_jar_on_gcs]
 
+    # [START howto_operator_start_java_job_local_jar]
     jar_to_local = GCSToLocalFilesystemOperator(
         task_id="jar-to-local",
         bucket=GCS_JAR_BUCKET_NAME,
@@ -99,6 +100,7 @@
         check_if_running=CheckJobRunning.WaitForRun,
     )
     jar_to_local >> start_java_job_local
+    # [END howto_operator_start_java_job_local_jar]
 
 with models.DAG(
     "example_gcp_dataflow_native_python",
@@ -144,6 +146,7 @@
     schedule_interval=None,  # Override to match your needs
     tags=['example'],
 ) as dag_native_python_async:
+    # [START howto_operator_start_python_job_async]
     start_python_job_async = DataflowCreatePythonJobOperator(
         task_id="start-python-job-async",
         py_file=GCS_PYTHON,
@@ -158,14 +161,18 @@
         location='europe-west3',
         wait_until_finished=False,
     )
+    # [END howto_operator_start_python_job_async]
 
+    # [START howto_sensor_wait_for_job_status]
     wait_for_python_job_async_done = DataflowJobStatusSensor(
         task_id="wait-for-python-job-async-done",
         job_id="{{task_instance.xcom_pull('start-python-job-async')['job_id']}}",
         expected_statuses={DataflowJobStatus.JOB_STATE_DONE},
         location='europe-west3',
     )
+    # [END howto_sensor_wait_for_job_status]
 
+    # [START howto_sensor_wait_for_job_metric]
     def check_metric_scalar_gte(metric_name: str, value: int) -> Callable:
         """Check is metric greater than equals to given value."""
 
@@ -187,7 +194,9 @@ def callback(metrics: List[Dict]) -> bool:
         location='europe-west3',
         callback=check_metric_scalar_gte(metric_name="Service-cpu_num_seconds", value=100),
     )
+    # [END howto_sensor_wait_for_job_metric]
 
+    # [START howto_sensor_wait_for_job_message]
     def check_message(messages: List[dict]) -> bool:
         """Check message"""
         for message in messages:
@@ -201,7 +210,9 @@ def check_message(messages: List[dict]) -> bool:
         location='europe-west3',
         callback=check_message,
     )
+    # [END howto_sensor_wait_for_job_message]
 
+    # [START howto_sensor_wait_for_job_autoscaling_event]
     def check_autoscaling_event(autoscaling_events: List[dict]) -> bool:
         """Check autoscaling event"""
         for autoscaling_event in autoscaling_events:
@@ -215,6 +226,7 @@ def check_autoscaling_event(autoscaling_events: List[dict]) -> bool:
         location='europe-west3',
         callback=check_autoscaling_event,
     )
+    # [END howto_sensor_wait_for_job_autoscaling_event]
 
     start_python_job_async >> wait_for_python_job_async_done
     start_python_job_async >> wait_for_python_job_async_metric
@@ -229,9 +241,11 @@ def check_autoscaling_event(autoscaling_events: List[dict]) -> bool:
     schedule_interval=None,  # Override to match your needs
     tags=['example'],
 ) as dag_template:
+    # [START howto_operator_start_template_job]
     start_template_job = DataflowTemplatedJobStartOperator(
         task_id="start-template-job",
         template='gs://dataflow-templates/latest/Word_Count',
         parameters={'inputFile': "gs://dataflow-samples/shakespeare/kinglear.txt", 'output': GCS_OUTPUT},
         location='europe-west3',
     )
+    # [END howto_operator_start_template_job]

airflow/providers/google/cloud/example_dags/example_dataflow_flex_template.py

@@ -44,6 +44,7 @@
     start_date=days_ago(1),
     schedule_interval=None,  # Override to match your needs
 ) as dag_flex_template:
+    # [START howto_operator_start_template_job]
     start_flex_template = DataflowStartFlexTemplateOperator(
         task_id="start_flex_template_streaming_beam_sql",
         body={
@@ -59,3 +60,4 @@
         do_xcom_push=True,
         location=BQ_FLEX_TEMPLATE_LOCATION,
     )
+    # [END howto_operator_start_template_job]

airflow/providers/google/cloud/example_dags/example_dataflow_sql.py

@@ -39,6 +39,7 @@
     schedule_interval=None,  # Override to match your needs
     tags=['example'],
 ) as dag_sql:
+    # [START howto_operator_start_sql_job]
     start_sql = DataflowStartSqlJobOperator(
         task_id="start_sql_query",
         job_name=DATAFLOW_SQL_JOB_NAME,
@@ -61,3 +62,4 @@
         location=DATAFLOW_SQL_LOCATION,
         do_xcom_push=True,
     )
+    # [END howto_operator_start_sql_job]

airflow/providers/google/cloud/operators/dataflow.py

@@ -87,6 +87,10 @@ class DataflowCreateJavaJobOperator(BaseOperator):
         For more detail on job submission have a look at the reference:
         https://cloud.google.com/dataflow/pipelines/specifying-exec-params
 
+    .. seealso::
+        For more information on how to use this operator, take a look at the guide:
+        :ref:`howto/operator:DataflowCreateJavaJobOperator`
+
     :param jar: The reference to a self executing DataFlow jar (templated).
     :type jar: str
     :param job_name: The 'jobName' to use when executing the DataFlow job
@@ -321,6 +325,10 @@ class DataflowTemplatedJobStartOperator(BaseOperator):
     Start a Templated Cloud DataFlow job. The parameters of the operation
     will be passed to the job.
 
+    .. seealso::
+        For more information on how to use this operator, take a look at the guide:
+        :ref:`howto/operator:DataflowTemplatedJobStartOperator`
+
     :param template: The reference to the DataFlow template.
     :type template: str
     :param job_name: The 'jobName' to use when executing the DataFlow template
@@ -543,6 +551,10 @@ class DataflowStartFlexTemplateOperator(BaseOperator):
     """
     Starts flex templates with the Dataflow pipeline.
 
+    .. seealso::
+        For more information on how to use this operator, take a look at the guide:
+        :ref:`howto/operator:DataflowStartFlexTemplateOperator`
+
     :param body: The request body. See:
         https://cloud.google.com/dataflow/docs/reference/rest/v1b3/projects.locations.flexTemplates/launch#request-body
     :param location: The location of the Dataflow job (for example europe-west1)
@@ -659,6 +671,14 @@ class DataflowStartSqlJobOperator(BaseOperator):
     """
     Starts Dataflow SQL query.
 
+    .. seealso::
+        For more information on how to use this operator, take a look at the guide:
+        :ref:`howto/operator:DataflowStartSqlJobOperator`
+
+    .. warning::
+        This operator requires ``gcloud`` command (Google Cloud SDK) must be installed on the Airflow worker
+        <https://cloud.google.com/sdk/docs/install>`__
+
     :param job_name: The unique name to assign to the Cloud Dataflow job.
     :type job_name: str
     :param query: The SQL query to execute.
@@ -764,6 +784,10 @@ class DataflowCreatePythonJobOperator(BaseOperator):
         For more detail on job submission have a look at the reference:
         https://cloud.google.com/dataflow/pipelines/specifying-exec-params
 
+    .. seealso::
+        For more information on how to use this operator, take a look at the guide:
+        :ref:`howto/operator:DataflowCreatePythonJobOperator`
+
     :param py_file: Reference to the python dataflow pipeline file.py, e.g.,
         /some/local/file/path/to/your/python/pipeline/file. (templated)
     :type py_file: str

airflow/providers/google/cloud/sensors/dataflow.py

@@ -32,6 +32,10 @@ class DataflowJobStatusSensor(BaseSensorOperator):
     """
     Checks for the status of a job in Google Cloud Dataflow.
 
+    .. seealso::
+        For more information on how to use this operator, take a look at the guide:
+        :ref:`howto/operator:DataflowJobStatusSensor`
+
     :param job_id: ID of the job to be checked.
     :type job_id: str
     :param expected_statuses: The expected state of the operation.
@@ -122,6 +126,10 @@ class DataflowJobMetricsSensor(BaseSensorOperator):
     """
     Checks the metrics of a job in Google Cloud Dataflow.
 
+    .. seealso::
+        For more information on how to use this operator, take a look at the guide:
+        :ref:`howto/operator:DataflowJobMetricsSensor`
+
     :param job_id: ID of the job to be checked.
     :type job_id: str
     :param callback: callback which is called with list of read job metrics
@@ -212,6 +220,10 @@ class DataflowJobMessagesSensor(BaseSensorOperator):
     """
     Checks for the job message in Google Cloud Dataflow.
 
+    .. seealso::
+        For more information on how to use this operator, take a look at the guide:
+        :ref:`howto/operator:DataflowJobMessagesSensor`
+
     :param job_id: ID of the job to be checked.
     :type job_id: str
     :param callback: callback which is called with list of read job metrics
@@ -302,6 +314,10 @@ class DataflowJobAutoScalingEventsSensor(BaseSensorOperator):
     """
     Checks for the job autoscaling event in Google Cloud Dataflow.
 
+    .. seealso::
+        For more information on how to use this operator, take a look at the guide:
+        :ref:`howto/operator:DataflowJobAutoScalingEventsSensor`
+
     :param job_id: ID of the job to be checked.
     :type job_id: str
     :param callback: callback which is called with list of read job metrics

airflow/providers/google/provider.yaml

@@ -201,6 +201,8 @@ integrations:
     tags: [gcp]
   - integration-name: Google Dataflow
     external-doc-url: https://cloud.google.com/dataflow/
+    how-to-guide:
+      - /docs/apache-airflow-providers-google/operators/cloud/dataflow.rst
     logo: /integration-logos/gcp/Cloud-Dataflow.png
     tags: [gcp]
   - integration-name: Google Data Fusion