I just did this a couple weeks ago. Was going to take metro, but it was shut down with a bus bridge connection due to maintenance that day. Uber was fairly cheap (airport surcharge was QAR 8).
Do note that you cannot rely on wifi currently because you need the Ehteraz app to be running and have a green QR code at all times when entering buildings (including to get into the airport). This requires a valid phone number and data connection when in Qatar.