@ IN SOA ${soa.primary}. ${builtins.replaceStrings ["@"] ["."] soa.email}. ${soa.serial} ${soa.refresh} ${soa.retry} ${soa.expire} ${soa.ttl}
${lib.concatStringsSep "\n" (map (x: "@ IN NS ${x}.") (lib.concatMap (n: lib.attrsets.mapAttrsToList (k: v: k) ns.${n}) conf.ns))}
@ IN SOA ${soa.primary}. ${builtins.replaceStrings ["@"] ["."] soa.email}. ${soa.serial} ${soa.refresh} ${soa.retry} ${soa.expire} ${soa.ttl}
${lib.concatStringsSep "\n" (map (x: "@ IN NS ${x}.") (lib.concatMap (n: lib.attrsets.mapAttrsToList (k: v: k) ns.${n}) conf.ns))}