SFTPStorage.url returns a sftp:// URL
def url(self, name): """ Returns an absolute URL where the file's contents can be accessed directly by a Web browser. """ raise NotImplementedError()
However, the SFTPStorage implementation returns sftp://host/path which isn't directly accessible by any client. At least not in my use case.
In my use case I have a separate webserver and I want to use SFTP to upload files there. So in essence replace MEDIA_ROOT with SFTP_STORAGE_ROOT, but MEDIA_URL should still work.