<?php
$CONFIG = array (
  'objectstore' => array(
    'class' => '\OC\Files\ObjectStore\S3',
    'arguments' => array(
      'bucket' => 'YOUR-BUCKET-NAME',
      'region' => 'YOUR-BUCKET-REGION',
      'key'    => 'YOUR_AWS_ACCESS_KEY_ID',
      'secret' => 'YOUR_AWS_SECRET_ACCESS_KEY',
      // Optional:
      // 'use_ssl' => true,
      // 'use_path_style' => false,
      // 'hostname' => 's3.YOUR-BUCKET-REGION.amazonaws.com',
    ),
  ),
);