In server-vars.yml set:

EDXAPP_FEATURES:
  ENABLE_S3_GRADE_DOWNLOADS: true
  ALLOW_COURSE_STAFF_GRADE_DOWNLOADS: true

EDXAPP_GRADE_BUCKET: "grade-bucket-name"
EDXAPP_GRADE_STORAGE_TYPE: "S3"
EDXAPP_GRADE_ROOT_PATH: 'any/folder/structure'

EDXAPP_AWS_ACCESS_KEY_ID: "xxxxxx"
EDXAPP_AWS_SECRET_ACCESS_KEY: "xxxxxx"

After set the credentials in {c,l}ms.env.json and restart edxapp by running:

/edx/bin/update edx-platform BRANCH_NAME

And restart the edxapp_workers with:

/edx/bin/supervisorctrl restart edxapp_worker:

—

The library xsiftx is really useful if you want to test the S3 credentials in your *.json files.

https://github.com/mitocw/xsiftx

sudo su edxapp -s /bin/bash
cd /edx/app/edxapp
source edxapp_env
pip install xsiftx

Then to test it out:

cd /edx/app/edxapp/edx-platform
xsiftx -c <course_key> test_sifters

And if everything works, you should see a “test_sifters” file in EDXAPP_GRADE_BUCKET

—

https://groups.google.com/forum/#!topic/openedx-ops/nU0NRIt_9OY