example_passing_params_via_test_command.py

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"""Example DAG demonstrating the usage of the params arguments in templated arguments."""

from __future__ import annotations

import datetime
import os
import textwrap

import pendulum

from airflow.decorators import task
from airflow.models.dag import DAG
from airflow.providers.standard.operators.bash import BashOperator


@task(task_id="run_this")
def my_py_command(params, test_mode=None, task=None):
    """
    Print out the "foo" param passed in via
    `airflow tasks test example_passing_params_via_test_command run_this <date>
    -t '{"foo":"bar"}'`
    """
    if test_mode:
        print(
            f" 'foo' was passed in via test={test_mode} command : kwargs[params][foo] = {task.params['foo']}"
        )
    # Print out the value of "miff", passed in below via the Python Operator
    print(f" 'miff' was passed in via task params = {params['miff']}")
    return 1


@task(task_id="env_var_test_task")
def print_env_vars(test_mode=None):
    """
    Print out the "foo" param passed in via
    `airflow tasks test example_passing_params_via_test_command env_var_test_task <date>
    --env-vars '{"foo":"bar"}'`
    """
    if test_mode:
        print(f"foo={os.environ.get('foo')}")
        print(f"AIRFLOW_TEST_MODE={os.environ.get('AIRFLOW_TEST_MODE')}")


with DAG(
    "example_passing_params_via_test_command",
    schedule="*/1 * * * *",
    start_date=pendulum.datetime(2021, 1, 1, tz="UTC"),
    catchup=False,
    dagrun_timeout=datetime.timedelta(minutes=4),
    tags=["example"],
) as dag:
    run_this = my_py_command(params={"miff": "agg"})

    my_command = textwrap.dedent(
        """
        echo "'foo' was passed in via Airflow CLI Test command with value '$FOO'"
        echo "'miff' was passed in via BashOperator with value '$MIFF'"
        """
    )

    also_run_this = BashOperator(
        task_id="also_run_this",
        bash_command=my_command,
        params={"miff": "agg"},
        env={"FOO": "{{ params.foo }}", "MIFF": "{{ params.miff }}"},
    )

    env_var_test_task = print_env_vars()

    run_this >> also_run_this