upload.clj

(resource
        {:id ::index
         :methods
         {:post
          {:consumes "application/octet-stream"
           :consumer (fn [ctx _ body-stream]
                       (let [f (java.io.File/createTempFile "yada" ".tmp" (io/file "/tmp"))]
                         (infof "Saving to file: %s" f)
                         (save-to-file
                          ctx body-stream
                          f)))
           :response (fn [ctx] (format "Thank you, saved upload content to file: %s\n" (:file ctx)))}}})