In the userspace implementation, would there be any interest in making the socket directory (/var/run/wireguard) customizable via an environment variable?

My use case for this is that I'd like to install and use WireGuard as a snapcraft package*, and the respective confinement restricts access to /var/run. Either way, having the ability to customize the path seems like sensible functionality.

The code change itself is of course pretty simple. I had a go at it here (https://github.com/WireGuard/wireguard-go/compare/master...svet-b:0.0.20181018) where an optional WG_SOCKET_DIR variable is introduced - and what I did works, though I have to admit that it's the first time I've ever written anything in go, so what I did is pretty ugly. Therefore I figured I'd reach out on this mailing list rather than submit a pull request.

Thanks, and keep up the great project!

Svet

*Yes, I understand that running the userspace implementation in Linux is not exactly ideal. I'm doing it on devices where I can't install kernel modules, and where squeezing out performance is not that important.