Looking at https://github.com/shazow/urllib3/pull/679, it would appear that urllib3 switch behaviour to preserve case sensitivity for headers; requests is just passing this through to glanceclient, which is coded on the previous behaviour where headers where converted to lowercase automatically.
Looking at https:/ /github. com/shazow/ urllib3/ pull/679, it would appear that urllib3 switch behaviour to preserve case sensitivity for headers; requests is just passing this through to glanceclient, which is coded on the previous behaviour where headers where converted to lowercase automatically.