This commit adds support for defining arbitrary peers that should have access to the VPN. In k8s, this is accomplished using the new Peer CRD.
Today, net.Listen will only listen on 127.0.0.1 if localhost is passed [0]. Listening on `:8080` will open a dualstack socket on OSs that support it. [0] https://github.com/golang/go/issues/9334