I've been automating deployment with the bpg Terraform module linked by a sibling (of mine) comment to Proxmox for work.
Neither option is particularly complete, and they have some issues; the bpg one does most of the heavy lifting over SSH rather than using the API due to missing features; it also has some annoying quirks with data structure, such as VM IPs are in multi-dimensional arrays, which means you have to write a bunch of logic to drop localhost and secondary IPs (such as those for Docker virtual networks), and then restructure the output, if you want to use the address to setup your DNS for example.
It's doing what I need now, but I would not call them "gold" or "platinum" grade, probably "silver".
I'd suggest seeing if Proxmox is better-supported in some other IaC tool and fallback to Terraform as a last resort.
Neither option is particularly complete, and they have some issues; the bpg one does most of the heavy lifting over SSH rather than using the API due to missing features; it also has some annoying quirks with data structure, such as VM IPs are in multi-dimensional arrays, which means you have to write a bunch of logic to drop localhost and secondary IPs (such as those for Docker virtual networks), and then restructure the output, if you want to use the address to setup your DNS for example.
It's doing what I need now, but I would not call them "gold" or "platinum" grade, probably "silver".
I'd suggest seeing if Proxmox is better-supported in some other IaC tool and fallback to Terraform as a last resort.