Azure File storage content-type is always application/octet-stream

Question

I'm currently having issue with Azure File storage when I build up a URL with a shared access signature (SAS) Token. The file will download in the browser, but the content-type is always application/octet-stream rather than changing to match the mime type of the file. If I put the file in Azure BLOB storage and build up a URL with a SAS Token, it sends the correct content-type for my file (image/jpeg).

I've upgraded my storage account from V1 to V2 thinking that was the problem, but it didn't fix it.

Does anyone have a clue what I could try that might get Azure File storage to return the correct content-type using a URL with SAS Token to download the file?

Answer 1

When I upload a jpeg file to file share through portal, content-type is changed to application/octet-stream indeed. But I can't reproduce your download problem.

I didn't specify content-type in my SAS request uri, but the file just download as a jpeg file. Have tested in SDK(Account SAS/Stored Access Policy/SAS on file itself) or REST API, both work even without content-type.

You can try to specify the content-type using the code below.

 SharedAccessFileHeaders header = new SharedAccessFileHeaders()
 {
     ContentDisposition = "attachment",
     ContentType = "image/jpeg"
 };
string sasToken = file.GetSharedAccessSignature(sharedPolicy,header);