Creating a custom plugin for Apache Airflow PythonVirtualenvOperator
The following sample explains how to patch the Apache Airflow PythonVirtualenvOperator with a custom plugin on Amazon Managed Workflows for Apache Airflow.
Topics
Version
You can use the code example on this page with Apache Airflow v2 in Python 3.10
Prerequisites
To use the sample code on this page, you'll need the following:
Permissions
No additional permissions are required to use the code example on this page.
Requirements
To use the sample code on this page, add the following dependencies to your requirements.txt. To learn more, refer to Installing Python dependencies.
virtualenv
Custom plugin sample code
Apache Airflow will execute the contents of Python files in the plugins folder at startup. This plugin will patch the built-in
PythonVirtualenvOperator during that startup process to make it compatible with Amazon MWAA. The following steps display the sample code for the custom plugin.
-
In your command prompt, navigate to the
pluginsdirectory in the previous section. For example:cd plugins -
Copy the contents of the following code sample and save locally as
virtual_python_plugin.py.""" Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. """ from airflow.plugins_manager import AirflowPlugin import airflow.utils.python_virtualenv from typing import List def _generate_virtualenv_cmd(tmp_dir: str, python_bin: str, system_site_packages: bool) -> List[str]: cmd = ['python3','/usr/local/airflow/.local/lib/python3.7/site-packages/virtualenv', tmp_dir] if system_site_packages: cmd.append('--system-site-packages') if python_bin is not None: cmd.append(f'--python={python_bin}') return cmd airflow.utils.python_virtualenv._generate_virtualenv_cmd=_generate_virtualenv_cmd class VirtualPythonPlugin(AirflowPlugin): name = 'virtual_python_plugin'
Plugins.zip
The following steps explain how to create the plugins.zip.
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In your command prompt, navigate to the directory containing
virtual_python_plugin.pyin the previous section. For example:cd plugins -
Zip the contents within your
pluginsfolder.zip plugins.zip virtual_python_plugin.py
Code sample
The following steps describe how to create the DAG code for the custom plugin.
-
In your command prompt, navigate to the directory where your DAG code is stored. For example:
cd dags -
Copy the contents of the following code sample and save locally as
virtualenv_test.py.""" Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. """ from airflow import DAG from airflow.operators.python import PythonVirtualenvOperator from airflow.utils.dates import days_ago import os os.environ["PATH"] = os.getenv("PATH") + ":/usr/local/airflow/.local/bin" def virtualenv_fn(): import boto3 print("boto3 version ",boto3.__version__) with DAG(dag_id="virtualenv_test", schedule_interval=None, catchup=False, start_date=days_ago(1)) as dag: virtualenv_task = PythonVirtualenvOperator( task_id="virtualenv_task", python_callable=virtualenv_fn, requirements=["boto3>=1.17.43"], system_site_packages=False, dag=dag, )
Airflow configuration options
If you're using Apache Airflow v2, add core.lazy_load_plugins : False as an Apache Airflow configuration option.
To learn more, refer to Using configuration options to load plugins in 2.
What's next?
-
Learn how to upload the
requirements.txtfile in this example to your Amazon S3 bucket in Installing Python dependencies. -
Learn how to upload the DAG code in this example to the
dagsfolder in your Amazon S3 bucket in Adding or updating DAGs. -
Learn more about how to upload the
plugins.zipfile in this example to your Amazon S3 bucket in Installing custom plugins.