Surprised nobody has mentioned YADM - it can do per-device files and/or per-device templating too (jinja2 syntax). It's just a thin wrapper around git so you can use any git commands too.
I put up my dotfiles here https://github.com/thingfox/dotfiles (sample documentation repository with examples), in it I show how I did the templating for ssh hosts amongst other configs.
This allows me to remove the most sensitive data and use the https://yadm.io/docs/encryption option for that.
The https://yadm.io/docs/bootstrap feature is also awesome as is https://yadm.io/docs/alternates