Facebook rejects attachements (particularly images) with application/octet-stream type. I've added content-type autodetection and I had to duplicate standard library CreateFormFile() function as it has hardcoded content type. (wtf? according to @bradfitz it's ok, but for me it looks more like an ego issue)
Some very light refactoring/renaming took place as well...
paked
commented
6 years ago 
Facebook rejects attachements (particularly images) with application/octet-stream type. I've added content-type autodetection and I had to duplicate standard library CreateFormFile() function as it has hardcoded content type. (wtf? according to @bradfitz it's ok, but for me it looks more like an ego issue) Some very light refactoring/renaming took place as well...