[BUG] node filter is required for ports when it seems like it isn't

[ibuildthecloud]

What did you do

The following fails

$ k3d cluster create -p 9443:443
FATA[0000] Malformed portmapping '9443:443' lacks a node filter, but there is more than one node (including the loadbalancer, if there is any). 

The help says the node filter is optional, which it is, only if you run --no-lb but if you run --no-lb you get the following warning.

$ k3d cluster create -p 9443:443 --no-lb
WARN[0000] No node filter specified      

It would be more straight forward it seems that if no nodefilter is specified it will default to @server[0] regardless of the configuration and not warn or fail. An INFO message saying which container the port was added to seems appropriate.

Which version of k3d

$ k3d version
k3d version v3.1.3
k3s version v1.18.9-k3s1 (default)

[iwilltry42]

Thanks for opening this issue @ibuildthecloud ! :)
I'm not sure, if defaulting to server-0 would be the most straightforward/expected way 🤔
Personally, I'd prefer to default to the loadbalancer, if there is any.
I think "urging" the user to explicitly specify a target node could result in less human errors, while I agree that we could default to a chosen node instead of erroring out.

[iwilltry42]

Hi @ibuildthecloud any other thoughts on this? 👍

[ericis]

@iwilltry42 I agree with both of you. I think it might be best to default to @server[0] when --no-lb is passed and @loadbalancer when it is not.