I was able to fix this using hte bindMounts
container option, like:
containers.flx_web =
{ autoStart = true;
privateNetwork = true;
hostAddress = "192.168.100.10";
localAddress = "192.168.100.11";
bindMounts = {
"/etc/resolv.conf" = {
hostPath = "/etc/resolv.conf";
isReadOnly = true;
};
};