When I had a dumb trainer, I used bluetooth for my HRM and a cheap speed sensor, and connected them to my phone.
I was using Trainer Road, but I bet there's some free software out there that will allow you to record basic info like that. Strava gave up on recording sensor data, so that's no good however. In principle, if you had some sort of GPS headunit then you could probably tell it to ignore the GPS data and record your roller rides. I did that with my Lezyne one when experimenting on the rollers...
I now use a spare laptop work were throwing out, plus an ANT+ dongle (again with TR) - ANT+ seems better with my pedals.