airflow pass parameter from cli

Question

Is there a way to pass a parameter to:

airflow trigger_dag dag_name {param}

?

I have a script that monitors a directory for files - when a file gets moves into the target directory I want to trigger the dag passing as a parameter the file path.

Answer 1

you can pass it like this:

airflow trigger_dag --conf {"file_variable": "/path/to/file"} dag_id

Then in your dag, you can access this variable using templating as follows:

{{ dag_run.conf.file_variable }}

If this doesn't work, sharing a simple version of your dag might help in getting better answers.

Answer 2

yes you can. Your Dag should have a Dag and a Bask Task like this:

from airflow.operators.bash_operators import BashOperator

args = {'start_date':datetime.now(),
        'owner':'airflow',}
dag = DAG(
      dag_id='param_dag', 
      default_args=args,
      schedule_interval=None)

bash_task=BashOperator(
     task_id="bash_task" 
     bash_command= 'bash ~/path/bashscript.sh {{ dag_run.conf["parameter"] if dag_run else "" }} ', 
    //bashscript your script you want to run and the dag_run.conf will hold the parameter you want to pass
     dag=dag)

Now on your command line just type the command:

 airflow trigger_dag dag_id --conf '{"parameter":"~/path" }'