Hi, I'm having trouble finding any information about the Cloud Controller Manager that ships with k3s, is it configurable? What does it work with?

It is just a stub. Enough to remove the uninitialized taint from nodes and set their internal/external IPs. It's meant to be used when you are not actually integrating with a cloud provider.

So if I were to deploy to bare-metal, I'd want/need it?

If you want a real one, disable the k3s default one and deploy the helm chart or what have you recommended by the actual cloud provider.

I meant on-prem, no cloud

Yes, if you're doing bare metal you would need it, or need to find some other way to remove the uninitialized taint from your nodes.

So I deployed directly to a machine earlier, and I disabled the CCM because I assumed it was cloud-related