Testing Airflow DAGs with Dagtest

For the dag owner, testing Airflow DAGs can be complicated and tedious. Kubectl cp your dag from local to pod, exec into the pod, and run a command? Install breeze? Why pull the Airflow image and start up the webserver / scheduler / triggerer if all we want is to test the addition of a new task?

It doesn’t have to be this hard. At Etsy, we’ve simplified testing dags for the dag owner with dagtest. Dagtest is a Python package that we house on our internal PyPi. It is a small client binary that makes HTTP requests to a test API. The test API is a simple Flask server that receives these requests and builds pods to run airflow dags backfill commands based on the options provided via dagtest. The simplest of these is a dry-run. Typically, users run test runs where the dag executes E2E for a single ds.

Equally important is the environment setup. We use an adhoc Airflow instance in a separate GCP environment with an SA that cannot write to Production buckets. This talk will discuss both.