I set up a workflow at $DAY_JOB for building the rootfs as a container and then "promoting" it to a vmdk and creating the ovf metadata file to allow it to be imported into VMWare as its own machine.
This was ~3 years ago and at least at the time I was annoyed at how little established tooling there seemed to be for doing an appliance image build offline— everyone was just like "why? Boot some public cloud-init template and use that as the basis for your terraform/ansible/whatever. If you actually need an OVF then export it from VMWare and be done with it."
On the other hand, once I got down in the weeds with things, I did find there were some bits that were a bit hairy about the promotion process— especially with "minimal" containers that have no users or init system, not to mention of course no filesystem, kernel, or bootloader, there is a fair bit that you have to do with a typical container to ready it for becoming a real boy.
