feat(modules): add duckdns service

modules/nixos/services/duckdns/default.nix

@@ -0,0 +1,30 @@
+{
+  lib,
+  namespace,
+  config,
+  host,
+  ...
+}: with lib; with lib.${namespace};
+let
+  cfg = config.${namespace}.services.duckdns;
+in {
+  options.${namespace}.services.duckdns = {
+    enable = mkEnableOption "Enable DuckDNS, the dynamic dns service. Will periodically refresh your IP.";
+  };
+
+  config = mkIf cfg.enable {
+    sops.secrets.duckdns = {
+      sopsFile = lib.snowfall.fs.get-file "secrets/duckdns.service.env";
+      format = "dotenv";
+    };
+
+    virtualisation.oci-containers.containers.duckdns = {
+      image = "lscr.io/linuxserver/duckdns:latest";
+      autoStart = true;
+      hostname = host;
+      environmentFiles = [
+        config.sops.secrets.duckdns.path
+      ];
+    };
+  };
+}