This command sets the pki.dns label = to uc-<IP ADDRESS>.vcloud.w.com, where <IP ADDRESS> is the ip address with octets seperated by dashes - instead of period .
docker node ls --format '{{.ID}}' | \
xargs docker node inspect $1 \
--format 'docker node update --label-add pki.dns=uc-{{join (split .Status.Addr ".") "-" }}.vcloud.w.com {{.ID}}' | sh