Add option to interact with individual VMs

[ent427]

Hi,

the CONTRIBUTION.md states:

It currently supports API methods contained under the following paths (assume an /api2/json prefix):

/cluster
/nodes

However, I couldn't come up with a way to reach /nodes/{node}/qemu/{vmid}/snapshot/{snapname}/rollback in order to rollback (and restart) a VM. Is it possible somehow and I am just unable to identify how?

Idea would be something like this:

func (s *NodeService) RollbackVM(node string, id uint32, snapshotName string) (*GetNodeQemuResponse, *http.Response, error) {
	u := fmt.Sprintf("nodes/%s/qemu/%d/snapshot/%s/rollback", node, id, snapshotName)

	req, err := s.client.NewRequest(http.MethodPost, u, nil)  //body needs to send start=1
	if err != nil {
		return nil, nil, err
	}

	d := new(string)
	resp, err := s.client.Do(req, d)
	if err != nil {
		return nil, resp, err
	}

	return nil, resp, nil
}

Please let me know if this is already possible, otherwise I'd offer to contribute.

[Starttoaster]

Hey! Thanks for making the Issue. I'd be happy to add this API method to the library but if you want to contribute it, it might come quicker!

From your code snippet the main thing I'd like changed is in the returns *GetNodeQemuResponse should actually be a struct specific to this function. And maybe the function name could be RollbackVMFromSnapshot? I'm not sure if there are multiple API paths that roll back a VM via different means, but this would help differentiate them if other rollback methods are added in the future. Other than that it looks good to me. It would help if you also add a test, but if you don't, I'd appreciate you adding sample JSON to the testdata directory like so https://github.com/Starttoaster/go-proxmox/tree/main/testdata/nodes and then I can write a test :)