create_large_style.rb

Asset.find_in_batches do |group|
  group.each do |asset|
    if asset.is_image?
      current_url = asset.resource.path
      new_url = asset.resource.path(:large)

      if AWS::S3::S3Object.exists? current_url, S3Config['bucket_name']
        begin
          AWS::S3::S3Object.copy current_url, new_url, S3Config['bucket_name'], :copy_acl => :true
          puts "File copied [#{current_url}] => [#{new_url}]."
        rescue
          puts "Copy failed"
        end
      end
    end
  end
end