/dag/{dag_id} returns stale dags without its serialized version unlike /dags/{dag_id}/details

[psg2]

Apache Airflow version: 2.1.1

Kubernetes version (if you are using kubernetes) (use kubectl version):

Environment:

• Cloud provider or hardware configuration: N/A
• OS (e.g. from /etc/os-release): N/A
• Kernel (e.g. uname -a): N/A
• Install tools: N/A
• Others: N/A

What happened:

After removing a dag from the filesystem, Airflow cleans up the SerializedDags table and updates the DAG table to mark the DAG with is_active as False. If you call the /dag/{dag_id} endpoint with the removed dag_id, it will return the stale information about the dag, but if you call the /dag/{dag_id}/details you will receive and 404 error Dag Not Found.

Slack thread: https://apache-airflow.slack.com/archives/CCPRP7943/p1625504228302500

What you expected to happen:

Receive a 404 Dag Not Found on /dag/{dag_id} as well.

How to reproduce it:

1. Write a DAG file
2. Wait for Airflow to parse it
3. Remove the file
4. Call the API

Anything else we need to know:

[boring-cyborg]

Thanks for opening your first issue here! Be sure to follow the issue template!

[mik-laj]

Endpoint /dag/{dag_id} returns the active DAGs by default. If you want access to all DAGs, you must use the is_active parameter. To access all DAGS - both active and inactive, you should pass in_active parameter. Thanks to this, you can access archived data, but by default, you have consistent UI with CLI (airflow dags list) and Web UI (/home/).

[potiuk]

Closed as per conversation in #16842