How to get the content from an HTTP POST request received in thin?

Question

I am using thin to receive HTTP POST requests, my server code is this:

http_server = proc do |env|
  # Want to make response dependent on content
  response = "Hello World!"
  [200, {"Connection" => "close", "Content-Length" => response.bytesize.to_s}, [response]]
end

Setting a breakpoint, I can see that I have received the content-type (json), and content length, but can't see the actual content. How can I retrieve the content from the request for processing?

Answer 1

You need to use the rack.input entry of the env object. From the Rack Spec:

The input stream is an IO-like object which contains the raw HTTP POST data. When applicable, its external encoding must be “ASCII-8BIT” and it must be opened in binary mode, for Ruby 1.9 compatibility. The input stream must respond to gets, each, read and rewind.

So you can call read on it like this:

http_server = proc do |env|

  json_string = env['rack.input'].read
  json_string.force_encoding 'utf-8' # since the body has ASCII-8BIT encoding,
                                     # but we know this is json, we can use
                                     # force_encoding to get the right encoding

  # parse json_string and do your stuff

  response = "Hello World!"
  [200, {"Connection" => "close", "Content-Length" => response.bytesize.to_s}, [response]]
end