kops get assets can list images and files needed by kOps.
Docs: https://kops.sigs.k8s.io/cli/kops_get_assets/
kops get asssets --copy can be used to mirror.
See:
See also our general list of mirroring options
kOps has documentation for using local assets to create a cluster at: https://kops.sigs.k8s.io/operations/asset-repository/
You can also configure containerd to use registry mirrors for in the kOps cluster spec.
You'll need to add an entry for "registry.k8s.io" with your mirror.
Docs: https://kops.sigs.k8s.io/cluster_spec/#registry-mirrors