Decode an App Engine Blobkey to a Google Cloud Storage Filename

Question

I\'ve got a database full of BlobKeys that were previously uploaded through the standard Google App Engine create_upload_url() process, and each of the uploads went to the same

Answer 1

You can get the cloudstorage filename only in the upload handler (fileInfo.gs_object_name) and store it in your database. After that it is lost and it seems not to be preserved in BlobInfo or other metadata structures.

Google says: Unlike BlobInfo metadata FileInfo metadata is not persisted to datastore. (There is no blob key either, but you can create one later if needed by calling create_gs_key.) You must save the gs_object_name yourself in your upload handler or this data will be lost.

https://developers.google.com/appengine/docs/python/blobstore/fileinfoclass

Update: I was able to decode a SDK-BlobKey in Blobstore-Viewer: "encoded_gs_file:base64-encoded-filename-here". However the real thing is not base64 encoded.

create_gs_key(filename, rpc=None) ... Google says: "Returns an encrypted blob key as a string." Does anyone have a guess why this is encrypted?

Answer 2

If you have blobKeys you can use: ImagesServiceFactory.makeImageFromBlob

Answer 3

From the statement in the docs, it looks like the generated GCS filenames are lost. You'll have to use gsutil to manually browse your bucket.

https://developers.google.com/storage/docs/gsutil/commands/ls