bulkupload without username/password prompt

Question

I have a process which generates daily some data, which I would like to update to a java app running on the appengine using bulkupload, using the command:

appcfg.py upload_data --url=http://your_app_id.appspot.com/_ah/remote_api --kind= --filename=

It works perfectly, but it always asks me for my username/password.

Is there any way to save the credentials, use certificates, to avoid the username prompt?

Answer 1

Add these options:

--email=
--passin
 and at the end :  < "your password file.txt"

Answer 2

Seems this technique no longer works with SDK 1.9.17. The updated docs include some new oauth2 command line options, but the instructions are rather confusing. Anyone able to use either the old passin or the new oauth2 techniques? How?