I've used this[1] Terraform provider together with the Talos[2] distribution for deploying a Kubernetes cluster. I agree that the APIs available with Proxmox are not fully featured, but it more than suits my needs.
I'm running a four node cluster on salvaged SFF machines backing up lvm snapshots to home brewed TruNAS storage and it all makes me happy.
You probably know this but it's good to run a cluster with an odd number of nodes. You don't even need another full node, just a quorum node like a RPi.
Yes, of course.. I'm actually in the process of replacing nodes. The original 3x Ryzen5 4-core 32Gb hosts are being replaced by Ryzen9 12-core 96Gb hosts.. its just taking a bit of time. As long as I only ever take one down for updates at a time, its no bother for a home-lab environment.
I'm running a four node cluster on salvaged SFF machines backing up lvm snapshots to home brewed TruNAS storage and it all makes me happy.
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[1] https://github.com/Telmate/terraform-provider-proxmox
[2] https://factory.talos.dev/