Replacing Vagrant with Terraform/OpenTofu

[a-v-popov]

Unfortunately, you cannot add new devices to an already-running lab.
https://blog.ipspace.net/2025/07/expanding-netlab-topology/

I wonder what would happen if Vagrant is replaced with OpenTofu + https://github.com/dmacvicar/terraform-provider-libvirt

[ipspace]

Had a quick look at its documentation:

• No support for something like Vagrant boxes (we'd have to manage that ourselves, or use disks with snapshots or some such)
• Couldn't find anything similar to P2P links over UDP tunnels, all networking seems to be relying on libvirt networks, which in turn use Linux bridges, so no LACP, STP issues...

Also, is this a problem worth solving?

[a-v-popov]

No support for something like Vagrant boxes

That is a good thing, right? In my opinion Vagrant box is a wrong abstraction.
All we need is https://libvirt.org/kbase/backing_chains.html

Couldn't find anything similar to...

I think Vagrant just passes parameters to libvirt.
As per goals

API Fidelity - Models the libvirt XML schemas directly instead of abstracting them, giving users full access to libvirt features. Schema coverage is bounded by what libvirtxml supports.

I guess, anything supported by libvirt should be either supported by provider or trivial to extend.

Also, is this a problem worth solving?

Yes, if you want to add another client host without restarting and re-licensing the whole 20 node topology.
But nowhere close to the top of my priority list, it is more of curiosity/idea post than a feature request.