httpi with curb (spnego and multipart file upload)

gistfile1.rb

require 'rubygems'
require 'httpi'
require 'curb'

# at some point before the request is made you'll need a kerberos ticket
# i.e., kinit -k -t ticket_path

image_path = "/tmp/some_image.jpg"

url = URI.escape("https://some_ssl_spnego_url.com/upload_file_here")

HTTPI.adapter = :curb
req = HTTPI::Request.new
req.url = url
  
# add the file to the body as a PostField
req.body = Curl::PostField.file("image", image_path){IO.read(image_path)}

# use spnego when in prod and devserver
req.auth.gssnegotiate

resp = HTTPI.post req do |http|
  http.use_ssl
  http.multipart_form_post = true
end
if resp.code == 200
  puts "Successfully uploaded image."
else
  puts "Error .... :("
end

Hi,
What if I wanted to send JSON data to my url instead of a file. Could you please tell me how to do that?

Best,
ANi