facter inside docker container missing dmi information

I am trying to upgrade our puppet installation from 2.7 (ubuntu 12.04) to 3.8 (ubuntu 16.04), then to latest on ubuntu 18.04 and one of our templates is failing because it can't find the productname fact in the docker container.

I read through the source code in lib/src/facts/linux/dmi_resolver.cc I see its checking for

if (exists("/sys/class/dmi/", ec)) {
             .
             .
            result.product_name = read("/sys/class/dmi/id/product_name");

which exists when i check it

$ cat /sys/class/dmi/id/product_name
PowerEdge R640

but facter productname does not return anything inside the docker container, so a ruby template using that fact is failing. It looks like all the dmi related facts are missing inside the container.

This is inside an ubuntu 16.04 docker container with facter version 2.4.6 on an ubuntu 18.04 host.

Any suggestions for getting this working correctly?