setting up airflow with bigquery operator

Question

I am experimenting with airflow for data pipelines. I unfortunately cannot get it to work with the bigquery operator so far. I have searched for a solution to the best of my ability but I am still stuck.. I am using the sequential executor running locally.

Here is my code:

from airflow import DAG
from airflow.contrib.operators.bigquery_operator import BigQueryOperator
from datetime import datetime, timedelta

default_args = {
    'owner': 'airflow',
    'depends_on_past': False,
    'start_date': datetime(2015, 6, 1),
    'email': ['example@gmail.com'],
    'email_on_failure': False,
    'email_on_retry': False,
    'retries': 1,
    'retry_delay': timedelta(minutes=5),
    # 'queue': 'bash_queue',
    # 'pool': 'backfill',
    # 'priority_weight': 10,
    # 'end_date': datetime(2016, 1, 1),
}

dag = DAG(
    dag_id='bigQueryPipeline', 
    default_args=default_args, 
    schedule_interval=timedelta(1)
)

t1 = BigQueryOperator(
    task_id='bigquery_test',
    bql='SELECT COUNT(userId) FROM [events:EVENTS_20160501]',
    destination_dataset_table=False,
    bigquery_conn_id='bigquery_default',
    delegate_to=False,
    udf_config=False,
    dag=dag,
)

The error message:

[2016-08-27 00:13:14,665] {models.py:1327} ERROR - 'project'
Traceback (most recent call last):
  File "/Users/jean.rodrigue/anaconda/bin/airflow", line 15, in <module>
    args.func(args)
  File "/Users/jean.rodrigue/anaconda/lib/python2.7/site-packages/airflow/bin/cli.py", line 352, in test
    ti.run(force=True, ignore_dependencies=True, test_mode=True)
  File "/Users/jean.rodrigue/anaconda/lib/python2.7/site-packages/airflow/utils/db.py", line 53, in wrapper
    result = func(*args, **kwargs)
  File "/Users/jean.rodrigue/anaconda/lib/python2.7/site-packages/airflow/models.py", line 1245, in run
    result = task_copy.execute(context=context)
  File "/Users/jean.rodrigue/anaconda/lib/python2.7/site-packages/airflow/contrib/operators/bigquery_operator.py", line 57, in execute
    conn = hook.get_conn()
  File "/Users/jean.rodrigue/anaconda/lib/python2.7/site-packages/airflow/contrib/hooks/bigquery_hook.py", line 54, in get_conn
    project = connection_extras['project']

Answer 1

Took me a while to finally find it as it's not documented very clearly. In the airflow UI, go to Admin -> Connection. That connection id is what is being referenced by the parameters bigquery_connection_id. You must add in the "extras" field a json object that defines a k,v pair of "project" : ""

You must also add keys for "service_account" and "key_path" if you have not explicitly authorized an account on the box you're running Airflow. (gcloud auth)

Answer 2

If you need to do this programmatically, I use this as an entrypoint in our stack to create the connection if it doesn't already exist:

from airflow.models import Connection
from airflow.settings import Session

session = Session()
gcp_conn = Connection(
    conn_id='bigquery',
    conn_type='google_cloud_platform',
    extra='{"extra__google_cloud_platform__project":"<YOUR PROJECT HERE>"}')
if not session.query(Connection).filter(
        Connection.conn_id == gcp_conn.conn_id).first():
    session.add(gcp_conn)
    session.commit()

Answer 3

Recently I fixed a similar problem by specifying both bigquery_conn_id and google_cloud_storage_conn_id like this:

t1 = BigQueryOperator(
  task_id='bigquery_test',
  bql='SELECT COUNT(userId) FROM [events:EVENTS_20160501]',
  destination_dataset_table=False,
  bigquery_conn_id='bigquery_default',             <-- Need these both
  google_cloud_storage_conn_id='bigquery_default', <-- becasue of inheritance 
  delegate_to=False,
  udf_config=False,
  dag=dag,
)

See more in this answer: https://stackoverflow.com/a/45664830/634627