nixos/godns: init module

Initial implementation of the GoDNS service module. This module allows users to enable and configure the GoDNS service on their NixOS system. It includes options for specifying the GoDNS package and the path to the configuration file.

Author: michaelvanstraten

nixos/doc/manual/release-notes/rl-2505.section.md

@@ -214,6 +214,9 @@
 - [ipfs-cluster](https://ipfscluster.io/), Pinset orchestration for IPFS. Available as [services.ipfs-cluster](#opt-services.ipfs-cluster.enable)
 
 - [bitbox-bridge](https://github.com/BitBoxSwiss/bitbox-bridge), a bridge software that connects BitBox hardware wallets to computers & web wallets like [Rabby](https://rabby.io/). Allows one to interact & transact with smart contracts, Web3 websites & financial services without storing private keys anywhere other than the hardware wallet. Available as [services.bitbox-bridge](#opt-services.bitbox-bridge.enable).
+
+- [GoDNS](https://github.com/TimothyYe/godns), a dynamic DNS client written in Go, which supports multiple DNS providers. Available as [services.godns](option.html#opt-services.godns.enable).
+
 <!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->
 
 ## Backward Incompatibilities {#sec-release-25.05-incompatibilities}

nixos/modules/module-list.nix

@@ -1137,6 +1137,7 @@
   ./services/networking/go-shadowsocks2.nix
   ./services/networking/gobgpd.nix
   ./services/networking/gokapi.nix
+  ./services/networking/godns.nix
   ./services/networking/gvpe.nix
   ./services/networking/hans.nix
   ./services/networking/harmonia.nix

nixos/modules/services/networking/godns.nix

@@ -0,0 +1,84 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+let
+  inherit (lib)
+    mkEnableOption
+    mkIf
+    mkOption
+    mkPackageOption
+    types
+    ;
+
+  cfg = config.services.godns;
+
+  settingsFormat = pkgs.formats.yaml { };
+in
+{
+  options.services.godns = {
+    enable = mkEnableOption "GoDNS service";
+
+    package = mkPackageOption pkgs "godns" { };
+
+    settings = mkOption {
+      type = types.submodule {
+        freeformType = settingsFormat.type;
+      };
+
+      description = ''
+        Configuration for GoDNS. Refer to the [configuration section](1) in the
+        GoDNS GitHub repository for details.
+
+        [1]: https://github.com/TimothyYe/godns?tab=readme-ov-file#configuration
+      '';
+
+      example = {
+        provider = "Cloudflare";
+        login_token_file = "$CREDENTIALS_DIRECTORY/login_token";
+        domains = [
+          {
+            domain_name = "example.com";
+            sub_domains = [ "foo" ];
+          }
+        ];
+        ipv6_urls = [
+          "https://api6.ipify.org"
+          "https://ip2location.io/ip"
+          "https://v6.ipinfo.io/ip"
+        ];
+        ip_type = "IPv6";
+        interval = 300;
+      };
+    };
+
+    loadCredential = lib.mkOption {
+      type = types.listOf types.str;
+      default = [ ];
+      example = [ "login_token:/path/to/login_token" ];
+      description = ''
+        This can be used to pass secrets to the systemd service without adding
+        them to the nix store.
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services.godns = {
+      description = "GoDNS service";
+      wantedBy = [ "multi-user.target" ];
+      after = [ "network.target" ];
+      serviceConfig = {
+        DynamicUser = true;
+        ExecStart = "${lib.getExe cfg.package} -c ${settingsFormat.generate "config.yaml" cfg.settings}";
+        LoadCredential = cfg.loadCredential;
+        Restart = "always";
+        RestartSec = "2s";
+      };
+    };
+  };
+
+  meta.maintainers = [ lib.maintainers.michaelvanstraten ];
+}