This week I had to work on a PoC to deploy OpenShift in Virtual Machines instead of bare-metal, like we did recently for the CentOS CI infra
Why in Virtual Machines (KVM guests) and not on bare-metal ? Well, there are cases where you have powerful/beefy machines, but not enough to meet the minimum number of nodes (at least 3 etcd nodes, and not even counting the real workers, at least 2 so 5 in total for bare minimum), while these nodes would perfectly (both at cpu/memory and storage) support the whole infra (assuming that you don't deploy all etcd/control planes nodes on the same physical node of course, and same for workers)
If you have a look at the official openshift documentation, you'll see that while all major cloud providers (AWS, Azure, GCP) are listed, there are also ways to deploy on bare-metal (what we did for CI infra), but also on RHEV, vSphere and Openstack too .. but nothing for plain KVM hypervisors (managed by libvirt in our cases).
But a VM is more or less like a bare-metal install, so what about we treat the VMs as bare-metal ? problem solved, right ? For our bare-metal deployment, we …