That’s not too easy methinks. You get kvm vm-s though gui/shell/api with proxmox, but no docker (they use lxc). Unless you set up a podman or similar inside it.
Other than that I’d say go with a xen (xcp-ng). Proxmox or esxi host, and spin up a vm as docker host.
I ditched docker in my latest setup, just running 2 machines in a proxmox cluster. I like lxc - as it’s got the footprint of docker and behaves like a vm
On the host of the nginx rev proxy or in nginx config files. Something seems to block the lookup from name to ip, as ip works you know the proxy works. Check dns config and nginx config on that host
It’s still a misuse of the word - if your software needs testing it’s not a candidate you would release unless you’re a multi-billion gaming company or Cisco