xcomargs

Example DAG demonstrating the usage of the XComArgs.

Airflow Fundamentals


Providers:

Run this DAG

1. Install Astronomer CLISkip if you already have the CLI

2. Initate the project:

3. Copy and paste the code below into a file in the

dags
directory.

4. Add the following to your requirements.txt file:

5. Run the DAG:

#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
"""Example DAG demonstrating the usage of the XComArgs."""
import logging
from airflow import DAG
from airflow.decorators import task
from airflow.operators.bash import BashOperator
from airflow.operators.python import PythonOperator, get_current_context
from airflow.utils.dates import days_ago
log = logging.getLogger(__name__)
def generate_value():
"""Dummy function"""
return "Bring me a shrubbery!"
@task()
def print_value(value):
"""Dummy function"""
ctx = get_current_context()
log.info("The knights of Ni say: %s (at %s)", value, ctx['ts'])
with DAG(
dag_id='example_xcom_args',
default_args={'owner': 'airflow'},
start_date=days_ago(2),
schedule_interval=None,
tags=['example'],
) as dag:
task1 = PythonOperator(
task_id='generate_value',
python_callable=generate_value,
)
print_value(task1.output)
with DAG(
"example_xcom_args_with_operators",
default_args={'owner': 'airflow'},
start_date=days_ago(2),
schedule_interval=None,
tags=['example'],
) as dag2:
bash_op1 = BashOperator(task_id="c", bash_command="echo c")
bash_op2 = BashOperator(task_id="d", bash_command="echo c")
xcom_args_a = print_value("first!")
xcom_args_b = print_value("second!")
bash_op1 >> xcom_args_a >> xcom_args_b >> bash_op2