How to take Node.js stream and send it to form endpoint (dropbox)

I have a readable stream (s3) that I would like to pipe to dropbox's put endpoint, however this does not support Transfer-Encoding: chunked required for streaming data.

I see 2 possible solutions

  1. read the stream into a variable of some sort then send up, memory can then be a problem
  2. write the stream to disk then read it back and upload, which feels dirty and will be slow

What is the best solution to this problem?