Attempt at displaying AIP-52 in the context of a current Airflow system test

leahexample_bigquery_operations.py

# https://github.com/apache/airflow/blob/main/tests/system/providers/google/cloud/bigquery/example_bigquery_operations.py
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"""
Example Airflow DAG for Google BigQuery service local file upload and external table creation.
"""
from __future__ import annotations

import os
from datetime import datetime
from pathlib import Path

from airflow import models
from airflow.utils.task_group import TaskGroup


from airflow.providers.google.cloud.operators.bigquery import (
    BigQueryCreateEmptyDatasetOperator,
    BigQueryCreateExternalTableOperator,
    BigQueryDeleteDatasetOperator,
)
from airflow.providers.google.cloud.operators.gcs import GCSCreateBucketOperator, GCSDeleteBucketOperator
from airflow.providers.google.cloud.transfers.local_to_gcs import LocalFilesystemToGCSOperator
from airflow.utils.trigger_rule import TriggerRule

ENV_ID = os.environ.get("SYSTEM_TESTS_ENV_ID")
DAG_ID = "bigquery_operations"

DATASET_NAME = f"dataset_{DAG_ID}_{ENV_ID}"
DATA_SAMPLE_GCS_BUCKET_NAME = f"bucket_{DAG_ID}_{ENV_ID}"
DATA_SAMPLE_GCS_OBJECT_NAME = "bigquery/us-states/us-states.csv"
CSV_FILE_LOCAL_PATH = str(Path(__file__).parent / "resources" / "us-states.csv")


with models.DAG(
    DAG_ID,
    schedule="@once",
    start_date=datetime(2021, 1, 1),
    catchup=False,
    tags=["example", "bigquery"],
) as dag:
    @setup_task
    @task_group
    def setup_tasks():
        create_bucket = GCSCreateBucketOperator(task_id="create_bucket", bucket_name=DATA_SAMPLE_GCS_BUCKET_NAME)

        create_dataset = BigQueryCreateEmptyDatasetOperator(task_id="create_dataset", dataset_id=DATASET_NAME)

    upload_file = LocalFilesystemToGCSOperator(
        task_id="upload_file_to_bucket",
        src=CSV_FILE_LOCAL_PATH,
        dst=DATA_SAMPLE_GCS_OBJECT_NAME,
        bucket=DATA_SAMPLE_GCS_BUCKET_NAME,
    )

    # [START howto_operator_bigquery_create_external_table]
    create_external_table = BigQueryCreateExternalTableOperator(
        task_id="create_external_table",
        destination_project_dataset_table=f"{DATASET_NAME}.external_table",
        bucket=DATA_SAMPLE_GCS_BUCKET_NAME,
        source_objects=[DATA_SAMPLE_GCS_OBJECT_NAME],
        schema_fields=[
            {"name": "emp_name", "type": "STRING", "mode": "REQUIRED"},
            {"name": "salary", "type": "INTEGER", "mode": "NULLABLE"},
        ],
    )
    # [END howto_operator_bigquery_create_external_table]
    @teardown_task
    @task_group
    def delete_tasks():
        delete_dataset = BigQueryDeleteDatasetOperator(
            task_id="delete_dataset",
            dataset_id=DATASET_NAME,
            delete_contents=True,
            trigger_rule=TriggerRule.ALL_DONE,
        )
        delete_bucket = GCSDeleteBucketOperator(
            task_id="delete_bucket", bucket_name=DATA_SAMPLE_GCS_BUCKET_NAME, trigger_rule=TriggerRule.ALL_DONE
        )

    (
        # TEST SETUP - will this still be called the same way?
        setup_tasks()
        # TEST BODY
        >> upload_file
        >> create_external_table
        # TEST TEARDOWN - will this still be called the same way?
        >> delete_tasks()
    )

    from tests.system.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.system.utils import get_test_run  # noqa: E402

# Needed to run the example DAG with pytest (see: tests/system/README.md#run_via_pytest)
test_run = get_test_run(dag)