### Amazon Managed Workflows for Apache Airflow (MWAA) Get DAG ID

If the dag parse is in the context of a DAG execution, this function will return the DAG ID.  

This work is based on the article
https://medium.com/apache-airflow/magic-loop-in-airflow-reloaded-3e1bd8fb6671

### Versions Supported

Apache Airflow 2.2.2, tested on Amazon MWAA.  Other 2.x versions and platforms may also work but are untested.

### Setup 

The function `GetCurrentDag()`, when referenced from an Airflow DAG, will return NULL if not part of a 
Celery Task execution, or will return the DAG ID string if it is.

The file `get_dag_id_example.py` creates N dags, one per table row, but will only retrieve SQL statement for 
particular table row if it is being called from a task, otherwise it skips that retrieval.  Simlarly, it
only creates the DAG itself if it is part of the Scheduler processing loop (`current_dag = None`) or
if the DAG has the same ID as the one currently being processed.

For MWAA, you can also use this code to avoid parsing files when triggered via CLI on the web server:

```
import os
from get_dag_id import GetCurrentDag

current_dag = GetCurrentDag()
container_name=os.getenv("MWAA_AIRFLOW_COMPONENT")
this_dag_file=["dag_id_defined_in_this_code","another_dag_id_in_this_code]

if not current_dag in this_dag_file and container_name=="webserver":
    raise ImportError()
```

### Files

* [2.2/get_dag_id.py](2.2/get_dag_id.py)
* [2.2/get_dag_id_example.py](2.2/get_dag_id_example.py)

### Requirements.txt needed

None

### Plugins needed 

None.

## Security

See [CONTRIBUTING](../../blob/main/CONTRIBUTING.md#security-issue-notifications) for more information.

## License

This library is licensed under the MIT-0 License. See the [LICENSE](../../blob/main/LICENSE) file.