Solving the Python generate_blob_sas SAS Token Issue for Azure Blob Copy Operations

Discover how to fix SAS token generation issues in Python for seamless Azure blob copy operations. Learn about the necessary permissions and proper token types to use. --- This video is based on the question https://stackoverflow.com/q/71877592/ asked by the user 'Yanek Syzonenko' ( https://stackoverflow.com/u/18806614/ ) and on the answer https://stackoverflow.com/a/71879034/ provided by the user 'Gaurav Mantri' ( https://stackoverflow.com/u/188096/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions. Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Python generate_blob_sas doesn't create right SAS token (failed on copy operation in azcopy) Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/licensing The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/by-sa/4.0/ ) license. If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com. --- Solving the Python generate_blob_sas SAS Token Issue for Azure Blob Copy Operations When using Azure Blob Storage, one common task developers face is copying blobs from one storage account to another. Occasionally, however, you may encounter an issue where the generated Shared Access Signature (SAS) token does not provide the necessary permissions, leading to errors during the copy operation. In this guide, we'll dive into this problem and provide a clear solution. Understanding the Problem In your situation, you've attempted to copy blobs from one Azure storage account to another using Python and azcopy. However, you're faced with an Authentication Failed error when generating your SAS token programmatically. The error message indicates that the token is either expired or lacking proper permissions. More specifically, if you manually create a token on the Azure portal, it works perfectly, but the one generated in your code does not. The error message is: [[See Video to Reveal this Text or Code Snippet]] Identifying the Root Cause After analyzing your code and the differences between the manually created and programmatically generated SAS tokens, two key issues stand out: Missing Permissions: The working SAS token includes both Read and List permissions, indicated by sp=rl, while the generated token only has Read permission (sp=r). Token Type Error: Your code is generating a SAS token at the blob level (sr=b), whereas the working token uses container-level permissions (sr=c). This distinction is crucial because copying multiple blobs (especially in a structured directory) requires container-level permissions. Solution Steps To resolve these issues and successfully copy blobs using azcopy, you need to follow these steps: 1. Update Permission Levels Ensure that your SAS token includes both Read and List permissions. This is critical when you want to operate over collections of blobs, such as when copying directories. 2. Generate Container-Level SAS Token Instead of generating a SAS token for a specific blob, generate one for the container that holds the blobs. You can achieve this by using the generate_container_sas function in your code. Here’s a revised version of your code snippet to incorporate these fixes: [[See Video to Reveal this Text or Code Snippet]] Conclusion By ensuring that your SAS token has both Read and List permissions and generating it at the container level, you should be able to avoid the authentication issues previously encountered. Using this approach allows for seamless copying of blobs from one Azure storage account to another, accommodating varying file structures with ease. If you follow these guidelines, your operations should proceed smoothly, enabling effective Azure Blob Storage management. Happy coding!