From 7584ff9a39bb24b00a175f3c003f952df149634b Mon Sep 17 00:00:00 2001
From: Henri Dohmen <henri.dohmen@stud.tu-darmstadt.de>
Date: Sat, 31 May 2025 14:22:37 +0200
Subject: [PATCH] dns

---
 flake.nix        |  4 +--
 host/default.nix |  4 ++-
 lib.nix          | 68 ++++++++++++++++--------------------------------
 var/lan-dns.nix  | 18 +++++++++++++
 var/wg.nix       |  3 +++
 5 files changed, 49 insertions(+), 48 deletions(-)
 create mode 100644 var/lan-dns.nix

diff --git a/flake.nix b/flake.nix
index 733c04b..dfceea2 100644
--- a/flake.nix
+++ b/flake.nix
@@ -26,9 +26,9 @@
       lib = nixpkgs.lib;
       lib' = import ./lib.nix { inherit lib; };
 
-      specialArgs = {
+      specialArgs = rec {
         inherit inputs lib';
-        var = (lib'.walk-dir ./var).map_import_with_lib;
+        var = (lib'.walk-dir ./var)._map (f: import f { inherit lib var; });
       };
       overlays = _: {
         nixpkgs.overlays = [ colmena.overlay ];
diff --git a/host/default.nix b/host/default.nix
index e735632..54044fe 100644
--- a/host/default.nix
+++ b/host/default.nix
@@ -1,4 +1,4 @@
-{ ... }:
+{ var, ... }:
 {
   imports = [
     ./boot.nix
@@ -7,4 +7,6 @@
     ./shell.nix
     ./users.nix
   ];
+
+  networking.extraHosts = var.lan-dns.hostsFile;
 }
diff --git a/lib.nix b/lib.nix
index 205c30c..213614f 100644
--- a/lib.nix
+++ b/lib.nix
@@ -1,51 +1,29 @@
 { lib, ... }:
 with builtins;
 let
-  lib' = rec {
-    walk-dir =
-      let
-        walk-dir-inner =
-          path:
-          let
-            dir = readDir path;
+  walk-dir-inner =
+    path:
+    let
+      dir = readDir path;
+    in
+    lib.mapAttrs' (filename: value: {
+      name = lib.removeSuffix ".nix" filename;
+      value =
+        if value == "regular" then
+          path + "/${filename}"
+        else if value == "directory" then
+          walk-dir-inner (path + "/${filename}")
+        else
+          throw "Items of type ${value} are unsupported.";
+    }) dir;
 
-          in
-          lib.mapAttrs' (filename: value: {
-            name = lib.removeSuffix ".nix" filename;
-            value =
-              if value == "regular" then
-                path + "/${filename}"
-              else if value == "directory" then
-                walk-dir-inner (path + "/${filename}")
-              else
-                throw "Items of type ${value} are unsupported.";
-          }) dir;
-
-        helper-attrs =
-          subpaths:
-          let
-            _files = lib.collect (x: isPath x || isString x) subpaths;
-            _nix_files = filter (lib.hasSuffix ".nix") _files;
-          in
-          rec {
-            to_mod = _: {
-              imports = _nix_files;
-            };
-            to_mod_without_default = without_default.to_mod;
-            collect_nix_files = _nix_files;
-            map_import = lib.mapAttrsRecursive (_: import) subpaths;
-            map_import_with_lib = lib.mapAttrsRecursive (_: x: (import x) { inherit lib lib'; }) subpaths;
-            without_default =
-              let
-                subpaths' = removeAttrs subpaths [ "default" ];
-              in
-              with-helper-attrs subpaths';
-          };
-
-        with-helper-attrs =
-          x: if isAttrs x then lib.mapAttrs (_: with-helper-attrs) x // helper-attrs x else x;
-      in
-      p: with-helper-attrs (walk-dir-inner p);
+  helper-attrs = subpaths: {
+    _map = f: lib.mapAttrsRecursive (_: f) subpaths;
   };
+
+  with-helper-attrs =
+    x: if isAttrs x then lib.mapAttrs (_: with-helper-attrs) x // helper-attrs x else x;
 in
-lib'
+{
+  walk-dir = p: with-helper-attrs (walk-dir-inner p);
+}
diff --git a/var/lan-dns.nix b/var/lan-dns.nix
new file mode 100644
index 0000000..39851dd
--- /dev/null
+++ b/var/lan-dns.nix
@@ -0,0 +1,18 @@
+{ lib, var, ... }:
+let
+  lan-tld = ".lan";
+  lan-base-domain = ".hdohmen.de";
+  lan-hosts = lib.mapAttrs' (name: value: {
+    name = "${name}${lan-tld}";
+    inherit value;
+  }) var.wg.ips;
+in
+rec {
+  hostsFile = lib.concatStringsSep "\n" (lib.mapAttrsFlatten (n: v: "${n}\t${v}") hosts);
+  hosts =
+    lan-hosts
+    // lib.mapAttrs' (name: value: {
+      name = "${name}${lan-base-domain}";
+      inherit value;
+    }) lan-hosts;
+}
diff --git a/var/wg.nix b/var/wg.nix
index 483f139..d3ac12d 100644
--- a/var/wg.nix
+++ b/var/wg.nix
@@ -32,4 +32,7 @@ rec {
       lib.attrValues (lib.filterAttrs (n: _: n != host) wireguard-network)
     );
 
+  ips =
+    with builtins;
+    mapAttrs (name: value: head (lib.splitString "/" (head value.ips))) wireguard-network;
 }