okd/roles/openshift_control_plane/tasks/bootstrap_settings.yml

---
- name: modify controller args
  yedit:
    src: /etc/origin/master/master-config.yaml
    edits:
    - key: kubernetesMasterConfig.controllerArguments.cluster-signing-cert-file
      value:
      - /etc/origin/master/ca.crt
    - key: kubernetesMasterConfig.controllerArguments.cluster-signing-key-file
      value:
      - /etc/origin/master/ca.key
  notify: restart master