tripleo-ansible/tripleo_ansible/roles/designate_bind_pool/templates/rndc.conf.j2

key "rndc-key" {
        algorithm hmac-sha256;
        secret "{{ designate_rndc_key }}";
};

options {
{% if defined designate_worker_source_address %}
    default-source-address {{ designate_worker_source_address }};
{% endif %}
    default-key "rndc-key";
};