Nodejs: Uploading a stream to form-data results in 411 'Length-required'

Question

I'm trying to upload a file to the storyblock API. This uses S3 behind the scenes. Local file uploads work, but when trying to fetch a file from an external URL I get a 411 error.

This works:

    import { createReadStream } from 'fs'
    import FormData from 'form-data'
    
    const form = new FormData()
    form.append('file', createReadStream('./local-file.jpg))
    form.submit(...)

But when trying an external URL for the same file it doesn't:

    import FormData from 'form-data'
    import got, { type Got } from 'got'
    
    const form = new FormData()
    form.append('file', got.stream(externalUrl, {decompress: false})
    form.submit(...)

Response:

  statusCode: 411,
  statusMessage: 'Length Required',

Which indicates that somehow got.stream() gives a different stream output than createReadStream()

Answer 1

Content-Length header is missing that is why it's giving you 411. The size of file being uploaded needs be determined and then include the Content-Length header in the request. Add this before submit.

// Get the file size
const { headers } = await got.head(externalUrl);
const contentLength = headers['content-length'];
    
// Append the file to the form with the correct content length
form.append('file', stream, { knownLength: contentLength });