backup a directory with s3

Question

I am attempting to integrate an s3 backup for my images directory into a gem. I am having some difficulty getting the thing moved over into my bucket.

def backup_directory
     backup_file = Tempfile.new("dump")

     cmd = "#{RAILS_ROOT}/public/system/"
     cmd += " | gzip > #{backup_file.path}"
     run(cmd)

     backup_file
end

Tempfile.new is associated with the AWS/S3 gem

The method as show above gives me a Permission denied error. I have also used cp #{Rails_ROOT}/public/system/ but that also does not work.