c# - Uploading a Azure blob directly to SFTP server without an intermediate file

Question

I'm attempting to upload am Azure blob directly to an SFTP server.

It's simple to upload a file from a local location:

using (var sftp = new SftpClient(connectionInfo)){
    sftp.Connect();
    using (var uplfileStream = System.IO.File.OpenRead(fileName)){
        sftp.UploadFile(uplfileStream, fileName, true);
    }
    sftp.Disconnect();
}

Is there a way to copy blobs from blob storage directly to an SFTP server?

Answer 1

1. Either combine CloudBlob.OpenRead with SftpClient.UploadFile:

    using (var blobReadStream = blockBlob.OpenRead())
    {
        sftp.UploadFile(blobReadStream, remotePath, true);
    }
   

2. Or combine SftpClient.Create with CloudBlob.DownloadToStream:

    using (var sftpWriteStream = sftp.Create(remotePath))
    {
        blockBlob.DownloadToStream(sftpWriteStream);
    }
   

The first approach should be a way faster in SFTP terms, as SftpClient.UploadFile is optimized, comparing to the SftpFileStream returned by SftpClient.Create.