Question

I am using patron gem for creating curl request. Here is the code

    s = Patron::Session.new
    s.connect_timeout = 15
    s.timeout = 15
    s.base_url = API_URL
    s.headers['Date'] = DATE_HEADER
    s.headers['Accept'] = 'application/xml'
    s.headers['Content-Type'] = 'application/json'
    s.headers['Authorization'] = "API" + " " + auth_token
    response = s.delete(uri)
    response.status

How can I get the original curl request made by this gem?

Answer 1

You can’t. Err… you can, by monkey_patching the Patron::Session.request method, and yielding the request just before the handling. But beware that this is not the “libcurl” request, as this only exists in C code, it’s a Patron::Request instance.

Also, beware that your monkey-patching may break at any time, as you have to rewrite the whole method!

You add a yield just before handling the request to libcurl, so you have the opportunity to get it with a block.

req = nil
response = s.delete(uri) do |r|
  req = r
end
# now req should be your request instance.

Here is a hint for a patch:

class Patron::Session

# You have to patch all the standard methods to accept a block
def get(url, headers = {}, &block)
  request(:get, url, headers, &block)
end
# do the same for get_file, head, delete, put, put_file, post, post_file and post_multipart


def request(action, url, headers, options = {}, &block)
  # If the Expect header isn't set uploads are really slow
  headers['Expect'] ||= ''

  req = Request.new
  req.action                 = action
  req.headers                = self.headers.merge headers
  req.timeout                = options.fetch :timeout,               self.timeout
  req.connect_timeout        = options.fetch :connect_timeout,       self.connect_timeout
  req.max_redirects          = options.fetch :max_redirects,         self.max_redirects
  req.username               = options.fetch :username,              self.username
  req.password               = options.fetch :password,              self.password
  req.proxy                  = options.fetch :proxy,                 self.proxy
  req.proxy_type             = options.fetch :proxy_type,            self.proxy_type
  req.auth_type              = options.fetch :auth_type,             self.auth_type
  req.insecure               = options.fetch :insecure,              self.insecure
  req.ignore_content_length  = options.fetch :ignore_content_length, self.ignore_content_length
  req.buffer_size            = options.fetch :buffer_size,           self.buffer_size
  req.multipart              = options[:multipart]
  req.upload_data            = options[:data]
  req.file_name              = options[:file]

  base_url = self.base_url.to_s
  url = url.to_s
  raise ArgumentError, "Empty URL" if base_url.empty? && url.empty?
  uri = URI.join(base_url, url)
  query = uri.query.to_s.split('&')
  query += options[:query].is_a?(Hash) ? Util.build_query_pairs_from_hash(options[:query]) : options[:query].to_s.split('&')
  uri.query = query.join('&')
  uri.query = nil if uri.query.empty?
  url = uri.to_s
  req.url = url

  yield req if block_given? # added line

  handle_request(req)
end
end