Hi Paul, welcome
Just guessing, but it looks like there is a variable (“registry_ip”) that’s being sent as a string rather than interpreted.
Out of interest, do you know what steps you took to deploy kubernetes-core? My understanding is that there shouldn’t be a need to configure a private registry manually.
You should be able to run
juju run-action kubernetes-worker/leader registry
I believe that there’s also a private-registry charm, but I’ve read that its documentation is out-of-date.
The @k8s-charmers team can advise 