flake.nix

@@ -40,13 +40,7 @@
       overlays.madd = final: prev: mkPackages final;
       overlays.default = overlays.madd;
 
-      nixosModules.madd = {
+      nixosModules.madd = import ./nixos.nix { overlay = overlays.madd; };
-        imports = [
-          ./modules/madd-client.nix
-          ./modules/madd-server.nix
-        ];
-        config.nixpkgs.overlays = [ overlays.default ];
-      };
       nixosModules.default = nixosModules.madd;
     };
 }

modules/madd-client.nix

@@ -1,72 +0,0 @@
-{
-  lib,
-  pkgs,
-  config,
-  ...
-}:
-
-with lib;
-let
-  cfg = config.services.madd-client;
-in
-{
-  options.services.madd-client = {
-    enable = mkEnableOption "MADD client";
-    endpoint = mkOption {
-      type = types.str;
-      description = "Endpoint for MADD client to connect to.";
-    };
-    interface = mkOption {
-      type = types.str;
-      description = "Network interface to use for MADD client.";
-    };
-    priv-key-file = mkOption {
-      type = types.str;
-      default = "/etc/ssh/ssh_host_ed25519_key";
-      description = "Path to the private SSH key file identifying this machine.";
-    };
-    pub-key-file = mkOption {
-      type = types.str;
-      default = "${config.services.madd-client.priv-key-file}.pub";
-      description = "Path to the public SSH key file identifying this machine.";
-    };
-    hostname = mkOption {
-      type = types.str;
-      default = config.networking.hostName;
-      description = "Hostname to use for MADD client.";
-    };
-  };
-
-  config = mkIf cfg.enable {
-    systemd.services.madd-client = {
-      description = "MADD Client Service";
-      wantedBy = [ "multi-user.target" ];
-      after = [ "network-online.target" ];
-      requires = [ "network-online.target" ];
-      script = ''
-        function run_update {
-          ipv4=$(${pkgs.iproute2}/bin/ip -4 addr show dev "${cfg.interface}" | grep -Po 'inet \K[\d.]+' || true)
-          if [ -n "$ipv4" ]; then
-
-            export MADD_ENDPOINT="${cfg.endpoint}";
-            export MADD_PRIV_KEY="${cfg.priv-key-file}";
-            export MADD_PUB_KEY="${cfg.pub-key-file}";
-            export MADD_HOSTNAME="${cfg.hostname}";
-            export MADD_IP="$ipv4";
-
-            ${pkgs.madd-client}/bin/madd-client 2>/dev/null ;
-          fi
-        }
-
-        run_update
-
-        ${pkgs.iproute2}/bin/ip -4 monitor address label dev "${cfg.interface}" | while read -r event; do
-          if [[ $event == \[ADDR\]* ]]; then
-            echo "Detected address change"
-            run_update
-          fi
-        done
-      '';
-    };
-  };
-}

modules/madd-server.nix

@@ -1,79 +0,0 @@
-{
-  lib,
-  pkgs,
-  config,
-  ...
-}:
-
-with lib;
-let
-  cfg = config.services.madd-server;
-in
-{
-  options.services.madd-server = {
-    enable = mkEnableOption "MADD server";
-    settings = {
-      bind = mkOption {
-        type = types.str;
-        default = "0.0.0.0:5301";
-        description = "Address and port for MADD server to bind to.";
-      };
-      zone = mkOption {
-        type = types.str;
-        example = "lan.example.com";
-        description = "DNS zone under which the hosts are registered.";
-      };
-      networks = mkOption {
-        type = types.listOf types.str;
-        default = [ ];
-        example = [ "10.0.0.0/8" ];
-        description = "List of subnets to which hostnames can be registered.";
-      };
-      registration_limit = mkOption {
-        type = types.int;
-        default = 1;
-        description = "Maximum number of hostnames a single host can register.";
-      };
-      dns_server = mkOption {
-        type = types.str;
-        example = "localhost:53";
-        description = "DNS server to use. Must support dynamic updates.";
-      };
-      tsig_key_name = mkOption {
-        type = types.str;
-        default = "madd";
-        description = "TSIG key name for DNS updates.";
-      };
-      tsig_key_file = mkOption {
-        type = types.str;
-        default = "/etc/madd/tsig.key";
-        description = "Path to the TSIG key file for DNS updates. Must be encoded in base64.";
-      };
-      tsig_algorithm = mkOption {
-        type = types.str;
-        default = "hmac-sha256";
-        description = "TSIG algorithm to use for DNS updates.";
-      };
-      data_dir = mkOption {
-        type = types.str;
-        default = "/var/lib/madd";
-        description = "Directory where MADD server stores its data.";
-      };
-    };
-  };
-
-  config = mkIf cfg.enable {
-    environment.etc."madd/madd.toml".source = (pkgs.formats.toml { }).generate "madd.toml" cfg.settings;
-
-    systemd.services.madd-server = {
-      description = "MADD Server Service";
-      wantedBy = [ "multi-user.target" ];
-      after = [ "network-online.target" ];
-      requires = [ "network-online.target" ];
-      serviceConfig = {
-        ExecStart = "${pkgs.madd-server}/bin/madd-server";
-        Restart = "on-failure";
-      };
-    };
-  };
-}

nixos.nix

@@ -0,0 +1,78 @@
+{ overlay }:
+
+{
+  lib,
+  pkgs,
+  config,
+  ...
+}:
+
+with lib;
+{
+  options.services.madd-client = {
+    enable = mkEnableOption "MADD client";
+    endpoint = mkOption {
+      type = types.str;
+      description = "Endpoint for MADD client to connect to.";
+    };
+    interface = mkOption {
+      type = types.str;
+      default = "eth0";
+      description = "Network interface to use for MADD client.";
+    };
+    priv-key-file = mkOption {
+      type = types.str;
+      default = "/etc/ssh/ssh_host_ed25519_key";
+      description = "Path to the private SSH key file identifying this machine.";
+    };
+    pub-key-file = mkOption {
+      type = types.str;
+      default = "${config.services.madd-client.priv_key_file}.pub";
+      description = "Path to the public SSH key file identifying this machine.";
+    };
+    hostname = mkOption {
+      type = types.str;
+      default = config.networking.hostName;
+      description = "Hostname to use for MADD client.";
+    };
+  };
+
+  options.services.madd-server = {
+    enable = mkEnableOption "MADD server";
+  };
+
+  config = {
+    nixpkgs.overlays = [ overlay ];
+  }
+  // (
+    let
+      cfg = config.services.madd-client;
+    in
+    optionalAttrs config.madd-client.enable {
+      systemd.services.madd-client = {
+        description = "MADD Client Service";
+        wantedBy = [ "multi-user.target" ];
+        before = [ "network-pre.target" ];
+        requires = [ "network-pre.target" ];
+        script = ''
+          ${pkgs.iproute2}/bin/ip -4 monitor address label dev "${cfg.interface}" | while read -r event; do
+            if [[ $event == \[ADDR\]* ]]; then
+              ipv4=$(${pkgs.iproute2}/bin/ip -4 addr show dev "${cfg.interface}" | grep -Po 'inet \K[\d.]+')
+              if [ -n "$ipv4" ]; then
+
+                export MADD_ENDPOINT="${cfg.endpoint}"
+                export MADD_PRIV_KEY="${cfg.priv-key-file}"
+                export MADD_PUB_KEY="${cfg.pub-key-file}"
+                export MADD_HOSTNAME="${cfg.hostname}"
+                export MADD_IP="$ipv4"
+
+                ${pkgs.madd-client}/bin/madd-client
+              fi
+          done
+        '';
+      };
+    }
+  )
+  // (optionalAttrs config.madd-server.enable {
+  });
+}

src/dns.rs

@@ -267,9 +267,6 @@ async fn init_dns_registrations(
 async fn write_registrations(registrations: &Registrations, config: &Config) {
     let path = config.data_dir.join("registrations.toml");
     let contents = toml::to_string(registrations).unwrap();
-    if !config.data_dir.exists() {
-        tokio::fs::create_dir_all(&config.data_dir).await.unwrap();
-    }
     tokio::fs::write(path, contents).await.unwrap();
 }