{ lib, pkgs, config, ... }: with lib; let inherit (lib.types) attrsOf coercedTo listOf oneOf str int bool; cfg = config.services.smartdns; confFile = pkgs.writeText "smartdns.conf" (with generators; toKeyValue { mkKeyValue = mkKeyValueDefault { mkValueString = v: if isBool v then if v then "yes" else "no" else mkValueStringDefault { } v; } " "; listsAsDuplicateKeys = true; # Allowing duplications because we need to deal with multiple entries with the same key. } cfg.settings); in { options.services.smartdns = { enable = mkEnableOption "SmartDNS DNS server"; bindPort = mkOption { type = types.port; default = 53; description = lib.mdDoc "DNS listening port number."; }; settings = mkOption { type = let atom = oneOf [ str int bool ]; in attrsOf (coercedTo atom toList (listOf atom)); example = literalExpression '' { bind = ":5353 -no-rule -group example"; cache-size = 4096; server-tls = [ "8.8.8.8:853" "1.1.1.1:853" ]; server-https = "https://cloudflare-dns.com/dns-query -exclude-default-group"; prefetch-domain = true; speed-check-mode = "ping,tcp:80"; }; ''; description = lib.mdDoc '' A set that will be generated into configuration file, see the [SmartDNS README](https://github.com/pymumu/smartdns/blob/master/ReadMe_en.md#configuration-parameter) for details of configuration parameters. You could override the options here like {option}`services.smartdns.bindPort` by writing `settings.bind = ":5353 -no-rule -group example";`. ''; }; }; config = lib.mkIf cfg.enable { services.smartdns.settings.bind = mkDefault ":${toString cfg.bindPort}"; systemd.packages = [ pkgs.smartdns ]; systemd.services.smartdns.wantedBy = [ "multi-user.target" ]; systemd.services.smartdns.restartTriggers = [ confFile ]; environment.etc."smartdns/smartdns.conf".source = confFile; environment.etc."default/smartdns".source = "${pkgs.smartdns}/etc/default/smartdns"; }; }