The group value is expected in the envvars configmap, not the deployment.

• Include a terminology section defining:
  • what is a group and what is DNS Failover
  • active, inactive and ungrouped, active-groups TXT record.
• Set the active-groups TXT record.
• Update relevant envvar configmap for controllers to be grouped.
• Mention that ungrouped clusters are an option.
• Redeploy the controller.
• Confirm the zone is updated correctly.

Interesting points to include:

• Inactive controllers and ungrouped controllers do not process unpublishing (even their own records).
• For inactive groups records to be unpublished at least one active controller must exist.
• It's possible to have more than one active group at a time.
• It's possible to change the group of a controller afterwards.
• Known issue: DNS Operator - always write groupID to provider #637