[SOLVED] POST JSON data using drakma:http-request

POST JSON data using drakma:http-request

I am trying to POST some JSON data to a web service using drakma.

    (ql:quickload :st-json)
    (ql:quickload :cl-json)
    (ql:quickload :drakma)

    (defvar *rc* (merge-pathnames (user-homedir-pathname) ".apirc"))

    (defvar *user*
      (with-open-file (s *rc*)
        (st-json:read-json s)))

    (defvar api-url (st-json:getjso "url" *user*))
    (defvar api-key (st-json:getjso "key" *user*))
    (defvar api-email (st-json:getjso "email" *user*))

    (setf drakma:*header-stream* *standard-output*)

    (defvar *req* '(("date" . "20071001") ("time" . "00") ("origin" . "all")))

    (format t "json:~S~%" (json:encode-json-to-string *req*))

    (defun retrieve (api request)
      (let* ((cookie-jar (make-instance 'drakma:cookie-jar))
             (extra-headers (list (cons "From" api-email)
                                  (cons "X-API-KEY" api-key)))
             (url (concatenate 'string api-url api "/requests"))
             (stream (drakma:http-request url
                           :additional-headers extra-headers
                           :accept "application/json"
                           :method :post
                           :content-type "application/json"
                           :external-format-out :utf-8
                           :external-format-in :utf-8
                           :redirect 100
                           :cookie-jar cookie-jar
                   :content (json:encode-json-to-string request)
                           :want-stream t)))
          (st-json:read-json stream)))

 (retrieve "/datasets/tigge" *req*)

Unfortunately, I get an error, although the data seems to be encoded OK to JSON and the headers generated by drakma too, I think. Apparently something is wrong with the :content (the list of integers in the errors message is just the list of ASCII codes of the JSON encoded data).

json:"{\"date\":\"20071001\",\"time\":\"00\",\"origin\":\"all\",\"type\":\"pf\",\"param\":\"tp\",\"area\":\"70\\/-130\\/30\\/-60\",\"grid\":\"2\\/2\",\"target\":\"data.grib\"}"

POST /v1/datasets/tigge/requests HTTP/1.1
Host: api.service.int
User-Agent: Drakma/1.3.0 (SBCL 1.1.5; Darwin; 12.2.0; http://weitz.de/drakma/)
Accept: application/json
Connection: close
From: me@gmail.com
X-API-KEY: 19a0edb6d8d8dda1e6a3b21223e4f86a
Content-Type: application/json
Content-Length: 193


debugger invoked on a SIMPLE-TYPE-ERROR:
  The value of CL+SSL::THING is #(123 34 100 97 116 97 115 101 116 34 58 34
                              ...), which is not of type (SIMPLE-ARRAY
                                                          (UNSIGNED-BYTE 8)
                                                          (*)).

Any idea what's wrong with this code? Many thanks in advance.

Solution

Thanks to Kevin and Hans from the General interest list for Drakma and Chunga drakma-devel for helping me out - it turned out that the problem was caused by a bug in a recent version of cl+ssl, already fixed in a development branch. I use quicklisp, and here is what Hans Hübner advised my to do to update my cl+ssl installation, which worked:

You can check out the latest cl+ssl - which contains a fix for the problem:
cd ~/quicklisp/local-projects/
git clone git://gitorious.org/cl-plus-ssl/cl-plus-ssl.git
Quicklisp will automatically find cl+ssl from that location. Remember to remove that checkout after you've upgraded to a newer quicklisp release that has the fix in the future.