photo_controller.ex

def upload(photos) do
  ext = Path.extname(upload.filename)
  u = Ecto.UUID.generate
  flnm = "#{u}#{ext}"

  {:ok, file_binary} = File.read(upload.path)

  s3_bucket = "imagey-elixir"
  {:ok, _} =
    ExAws.S3.put_object(s3_bucket, flnm, file_binary)
    |> ExAws.request()
end