nixos/services: make dns configuration easier

nixos/modules/dns.nix

@@ -1,58 +1,100 @@
-{ config, ... }:
+{ config, lib, ... }:
 let
-  fqdn = "tuxcord.net";
-  # fqdn = config.networking.fqdn;
+  agenixDnsDir = ../../agenix/dns + "/${config.dns.domain}";
+  agenixKeys = builtins.attrNames (builtins.readDir agenixDnsDir);
 
-  zonesub = _: "zonesub";
-  subdomain = name: "subdomain ${name}";
+  keys = map (
+    filename:
+    let
+      zonesub = _: "zonesub";
+      subdomain = name: "subdomain ${name}";
 
-  # careful, assumes the fqdn (name) matches the key name content
-  keys = [
+      zoneDomain =
+        if lib.strings.hasSuffix ".key.age" filename then
+          lib.strings.removeSuffix ".key.age" filename
+        else
+          throw "${filename} is not a `.key.age` file";
+    in
     {
-      name = "tuxcord.net";
-      path = config.age.secrets.dns-root-key.path;
-      type = zonesub;
+      name = zoneDomain;
+      path = config.age.secrets."dns/${filename}".path;
+      type = if zoneDomain == config.dns.domain then zonesub else subdomain;
     }
-  ];
+  ) agenixKeys;
+
+  cfg = config.dns;
+  inherit (lib)
+    mkEnableOption
+    mkOption
+    mkIf
+    ;
 in
 {
-  services.bind = {
-    enable = true;
+  options.dns = {
+    enable = mkEnableOption "" // {
+      default = true;
+    };
 
-    extraConfig = builtins.concatStringsSep "\n" (map (key: "include \"${key.path}\";") keys);
-
-    zones = {
-      "${fqdn}" = {
-        # grant "tuxcord.net" zonesub ANY;
-        extraConfig = ''
-          update-policy {
-            ${builtins.concatStringsSep "\n" (
-              map (key: "grant \"${key.name}\" ${key.type key.name} ANY;") keys
-            )}
-          };
-        '';
-        file = "/var/dns/${fqdn}.zone"; # need to put default stuff
-        master = true;
-      };
+    domain = mkOption {
+      type = with lib.types; str;
+      default = config.networking.fqdn;
     };
   };
 
-  environment.persistence."/persist" = {
-    directories = [
+  config = mkIf cfg.enable {
+    age.secrets = builtins.listToAttrs (
+      map (
+        filename:
+        let
+          path = "${agenixDnsDir}/${filename}";
+        in
+        {
+          name = "dns/${filename}";
+          value = {
+            file = path;
+            group = "named";
+            owner = "named";
+          };
+        }
+      ) agenixKeys
+    );
+
+    services.bind = {
+      enable = true;
+
+      extraConfig = builtins.concatStringsSep "\n" (map (key: "include \"${key.path}\";") keys);
+
+      zones = {
+        "${config.dns.domain}" = {
+          # grant "tuxcord.net" zonesub ANY;
+          extraConfig = ''
+            update-policy {
+              ${builtins.concatStringsSep "\n" (
+                map (key: "grant \"${key.name}\" ${key.type key.name} ANY;") keys
+              )}
+            };
+          '';
+          file = "/var/dns/${config.dns.domain}.zone"; # need to put default stuff
+          master = true;
+        };
+      };
+    };
+
+    environment.persistence."/persist".directories = [
       {
         directory = "/var/dns";
         group = "named";
         user = "named";
       }
     ];
-  };
 
-  networking.firewall =
-    let
-      ports = [ config.services.bind.listenOnPort ];
-    in
-    {
-      allowedTCPPorts = ports;
-      allowedUDPPorts = ports;
-    };
+    networking.firewall =
+      let
+        ports = [ config.services.bind.listenOnPort ];
+      in
+      {
+        allowedTCPPorts = ports;
+        allowedUDPPorts = ports;
+      };
+  };
 }