Getting caddy in a container talk to tailscaled running on the Mac via home-brew

[jum]

Tailscale uses a unix domain socket to perform various functions, for example allocating https certificates for *.ts.net. I am unable to find an incantation that would allow me to mount /var/run/tailscale.socket to anything usable for my caddy container. is there a magic incantation I have to do to get unix sockets to work?