---
fixes:
  - |
    Fixes `monitor: kolla` be added in `external_labels` by default.
    Prometheus default config should not include environment-specific
    details. In this patch, modify `external_labels` be optional, we
    can add any `<labelname>: <labelvalue>` in `external_labels`.
    `LP#1944699 <https://bugs.launchpad.net/kolla-ansible/+bug/1944699>`__