https://github.com/cloudbees/casc-cloudbees-ci-eks-addon/blob/537797cab54805b11241505399260ed7d83f46eb/bp02.oc/jcasc/main.yaml#L42-L43 ought to define a DNS name pattern for static resources. This would have to map to the same actual services as the MCs. https://docs.cloudbees.com/docs/cloudbees-ci/latest/cloud-secure-guide/serving-resources-cloud#_configuring_the_resource_host
casc-cloudbees-ci-eks-addon/bp02.oc/jcasc/main.yaml
Lines 42 to 43 in 537797c