...
        db:
          metadata:
            label: "Database configuration"
            weight: 15
            group: "openstack_services"
          wsrep_method:
            value: "xtrabackup-v2"
            label: "WSREP SST provider"
            description: "This setting changes the wsrep_sst_method switch in the MySQL Galera cluster configuration."
            weight: 10
            type: "radio"
            values:
              - data: "xtrabackup-v2"
                label: "xtrabackup-v2"
                description: "Use Percona xtrabackup v2 provider."
              - data: "rsync"
                label: "rsync"
                description: "Use rsync provider."
              - data: "mysqldump"
                label: "mysqldump"
                description: "Use mysqldump provider (untested)."
        additional_components:
...