How can one use HashiCorp Vault in Airflow?

Question

I am starting to use Apache Airflow and I am wondering how to effectively make it use secrets and passwords stored in Vault. Unfortunately, search does not return meaningful answers beyond a yet-to-be-implemented hook in Airflow project itself.

I can always use Python's hvac module to generically access Vault from PythonOperator but I was wondering if there is any better way or a good practice (e.g. maybe an Airflow plugin I missed).

Answer 1

Airflow >=1.10.10 supports Secrets Backends and supports getting Airflow Variables and Connections from Hashicorp Vault.

More Details in Airflow Docs: https://airflow.apache.org/docs/stable/howto/use-alternative-secrets-backend.html#hashicorp-vault-secrets-backend

If you want to test it locally check the tutorial at https://www.astronomer.io/guides/airflow-and-hashicorp-vault/

Set the following config in airflow.cfg, update based on your environment:

backend = airflow.contrib.secrets.hashicorp_vault.VaultBackend
backend_kwargs = {"connections_path": "connections", "variables_path": "variables", "mount_point": "airflow", "url": "http://127.0.0.1:8200"}

Example DAG to test the integration:

from airflow import DAG
from airflow.operators.python_operator import PythonOperator
from datetime import datetime
from airflow.hooks.base_hook import BaseHook


def get_secrets(**kwargs):
    conn = BaseHook.get_connection(kwargs['my_conn_id'])
    print(f"Password: {conn.password}, Login: {conn.login}, URI: {conn.get_uri()}, Host: {conn.host}")

with DAG('example_secrets_dags', start_date=datetime(2020, 1, 1), schedule_interval=None) as dag:


    test_task = PythonOperator(
        task_id='test-task',
        python_callable=get_secrets,
        op_kwargs={'my_conn_id': 'smtp_default'},
    )

Answer 2

Additional things to keep eye on If you are new to Vault:

Validate that your airflow.cfg backend_kwargs parameter mount_point really exists in vault: vault secrets list

Try your DAG code above with command line first before trying it in web interface airflow test example_secrets_dags test-task 2020-06-04