Append to Azure blob zip file

Question

I've found tons of information about how to create and upload a zip file to Azure storage, but I'm trying to see if there's a good way to add content to an existing zip file in blob storage that doesn't involve downloading the whole blob, rebuilding in memory, then uploading again.

My use case involves zipping several hundred, up to several million, items into an archive to be stored in Azure blob storage for later download. I have code that will handle splitting so I don't wind up with a single several-GB size file, but I still run into memory management issues when dealing with large quantities of files. I'm trying to address this by creating the zip file in blob storage, and adding subsequent files to it one by one. I recognize this will incur cost for the additional writes, and that's fine.

I know how to use Append Blobs and Block Blobs, and I have working code to create the zip file and upload, but I can't seem to find out if there's a way to do this. Anyone managed to accomplish this, or able to confirm that this is not possible?

Answer 1

Since you're dealing with zip files, only way to add new files to an existing zip file is to download the blob, add new file to that zip file and then reupload that blob.