In the ever-evolving world of cloud computing, staying up-to-date with the latest technologies and best practices is crucial for the long-term success of your applications. Google Cloud’s Serverless Migration Station series, hosted by Wesley Chun, Developer Advocate at Google Cloud, aims to guide developers through the process of modernizing their applications. In this article, we explore Module 16 of the series, which focuses on migrating away from the Blobstore service in App Engine to embrace the power of Cloud Storage.
Why Migrate Away from Blobstore?
The Blobstore service in Google App Engine has been a reliable tool for storing and serving binary data. However, as technology evolves, certain limitations become apparent. These limitations include:
- Portability: Blobstore is tightly integrated with App Engine, making it challenging to migrate applications to other cloud platforms or frameworks. Migrating to Cloud Storage provides greater portability.
- Scalability: Cloud Storage is designed to handle massive amounts of data and traffic, making it a more suitable choice for applications that require scalability and high performance.
- Compatibility: Legacy services like Blobstore may become outdated or unsupported as technology advances. Migrating to Cloud Storage ensures your application remains compatible with the latest cloud technologies.
The Migration Journey
The migration journey from Blobstore to Cloud Storage is a multi-step process, and Module 16 of the Serverless Migration Station series covers it comprehensively. Here are the key steps involved:
1. Migrate from webapp2 to Flask: Transitioning from webapp2 to Flask, a popular and lightweight Python web framework, provides greater flexibility and modernization.
2. Migrate from App Engine NDB to Cloud NDB: Replace App Engine NDB with Cloud NDB, designed to be compatible with its predecessor, ensuring a smooth transition for your data operations.
3. Migrate from Blobstore to Cloud Storage: This is the core of the migration, where you transition from Blobstore to Cloud Storage for storing and serving binary data more efficiently.
4. Upgrade to Python 3: As Python 2 reaches its end of life, migrating your application to Python 3 is crucial to ensure long-term support and compatibility.
Implementation Details
Before diving into code modifications, several configuration updates are necessary to support the migration. These updates differ based on whether your application is migrating to Python 3 (Py3) or remains on Python 2 (Py2). Key configuration updates include:
- Removing the built-in Jinja2 library from app.yaml (Py2).
- Adding required libraries like grpcio and setuptools to app.yaml (Py2).
- Updating app.yaml to retain only a valid runtime (Py3).
- Including Cloud NDB and Cloud Storage client libraries in requirements.txt (Py2 & Py3).
- Creating an appengine_config.py file to support both built-in and non-built-in libraries (Py2).
The migration process also involves replacing webapp2 with Flask, transitioning from App Engine NDB to Cloud NDB, and reworking the upload and download handlers to utilize Cloud Storage effectively. These changes are essential for ensuring the compatibility and scalability of your application.
The Results
Upon completing the migration, your Python 2 or 3 App Engine application continues to operate seamlessly, offering the same features and capabilities as before. From an end-user perspective, nothing has changed—the application functions as expected.
However, under the hood, four significant migrations have been successfully completed. Your application now relies less on App Engine legacy services, making it more versatile, portable, and ready for the future of cloud computing.
Conclusion and Future Considerations
Modernizing your App Engine application by migrating from Blobstore to Cloud Storage is a strategic move to ensure its long-term viability and compatibility with evolving cloud technologies. While Blobstore served its purpose in the past, embracing Cloud Storage opens up new possibilities for scalability and portability.
It’s worth noting that, as of Fall 2021, the App Engine team extended support for bundled services to 2nd generation runtimes, eliminating the immediate need to migrate to Cloud Storage when porting your app to Python 3. You can continue using Blobstore in Python 3 apps, provided you adapt the code to access bundled services from next-generation runtimes.
The migration journey covered in Module 16 of the Serverless Migration Station series demonstrates Google Cloud’s commitment to helping developers transition to modern cloud technologies seamlessly. Whether you choose to migrate now or later, the goal remains the same: to future-proof your application and embrace the power of Cloud Storage.
For comprehensive guidance on each migration step and hands-on experience, be sure to explore the corresponding codelab accompanying Module 16. This step-by-step tutorial will walk you through the migration process, ensuring a smooth transition for your application.
As the cloud landscape continues to evolve, Google Cloud’s dedication to supporting developers remains unwavering. Stay tuned for future modules covering various language runtimes and more migration scenarios. Your cloud journey is just beginning, and Google Cloud is here to guide you every step of the way.
