The code bellow is a minimal working code that emulates the sequence of steps performed by DockerOperator ( _run_image), but because of the size is easier to generate null strings. On normal runs It's hard sometimes to see the issue 1 - sometimes returning null strings. Write_xcom_docker_warning > write_xcom_docker_all > type_dataĪ minimal code to generate null outputs from DockerOperator xcom_pull( task_ids = 'write_xcom_bash_pull')). Official Docker (container) images for Apache Airflow are described in IMAGES.rst. Extensible: Easily define your own operators. _name_ + ' | bash_xcom: ' + type( task_instance. Apache Airflow - A platform to programmatically author, schedule, and monitor workflows. xcom_pull( task_ids = 'write_xcom_docker_pull')). Python_callable = lambda task_instance: ( bash_operator import BashOperator params = """, The idea behind the DockerOperator is that it performs the equivalent of a docker run command (as shown in the previous section) to run a specified container. python_operator import PythonOperator from airflow. docker_operator import DockerOperator from airflow. dates import days_ago from datetime import timedelta from airflow. Let’s focus on t2 and the most commonly used parameters in order to configure the DockerOperator. Issue 3: If warnings/errors are returned, I expect airflow to log It, but not mess with xcom ( see screenshots bellow).Īirflow DAG to test xcom push and push_allįrom airflow import DAG from airflow. The last task t2, uses the DockerOperator in order to execute a command inside a Docker container.But this is not a good standard because requires extra transformation to be used by next operators ( see screenshots bellow). Airflow operators can be thought of as templates for a task. Right now DockerOperator encode back the data to bytes. uses Apache Airflow for their ETL processes running on AWS Managed Workflows for. You can open a new terminal and run the command docker ps to see the running containers. Issue 2: If xcom_push=True and xcom_push_all=True, I expect It to return all log lines to xcom.Issue 1: I expect (as per documentation) If xcom_push=True and xcom_push_all=False, (only) the last line of logs will be pushed to xcom.To speed up the end-to-end process, Airflow was created to quickly author, iterate on, and monitor batch data pipelines. Sending stderr to xcom can lead to undefined/non-deterministic behavior ( see screenshots bellow). Photo by Luis Jose Torrealba on Unsplash History Airflow was born out of Airbnb’s problem of dealing with large amounts of data that was being used in a variety of jobs. In practice, we don't want warnings and errors messing up with the code to be parsed on following operators (But we need to capture the output on airflow logs). Issue 3: Stderr and stdout are written to the same output xcom.BashOperator that writes output as string to xcom ( see screenshots bellow)). Issue 2: When xcom_push_all=True a bytes string ( b'.') is stored as xcom, It's harder to use the output on following operators and do not conform with other operators (e.g.
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