From 9abae8d2f5c5b0b8784ab423958087c9732b80aa Mon Sep 17 00:00:00 2001
From: mikl <mikl@iscg.dev>
Date: Mon, 3 Aug 2026 00:36:52 +0300
Subject: [PATCH] fix(mesh): create heather identity interface with systemd

---
 hosts/heather/default.nix | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/hosts/heather/default.nix b/hosts/heather/default.nix
index 40aabd7..df1e3ec 100644
--- a/hosts/heather/default.nix
+++ b/hosts/heather/default.nix
@@ -27,10 +27,25 @@
   # The private key is generated on the live host and stays outside the flake.
   environment.systemPackages = [ pkgs.wireguard-tools ];
 
-  systemd.network.netdevs."10-mesh0" = {
-    netdevConfig = { Name = "mesh0"; Kind = "dummy"; };
+  # NixOS uses scripted networking here (not systemd-networkd), so create the
+  # dummy identity interface through a small idempotent systemd unit.
+  systemd.services.mesh-identity = {
+    description = "Create mesh identity interface";
+    wantedBy = [ "network.target" ];
+    after = [ "wireguard-wg-mesh.service" "network-addresses-wg-mesh.service" ];
+    wants = [ "wireguard-wg-mesh.service" ];
+    serviceConfig = {
+      Type = "oneshot";
+      RemainAfterExit = true;
+      ExecStart = pkgs.writeShellScript "mesh-identity-up" ''
+        set -eu
+        ${pkgs.iproute2}/bin/ip link show mesh0 >/dev/null 2>&1 || ${pkgs.iproute2}/bin/ip link add mesh0 type dummy
+        ${pkgs.iproute2}/bin/ip addr replace 10.0.0.1/32 dev mesh0
+        ${pkgs.iproute2}/bin/ip link set mesh0 up
+      '';
+      ExecStop = "${pkgs.iproute2}/bin/ip link del mesh0";
+    };
   };
-  networking.interfaces.mesh0.ipv4.addresses = [ { address = "10.0.0.1"; prefixLength = 32; } ];
 
   networking.wireguard.interfaces.wg-mesh = {
     ips = [ "10.99.0.1/30" ];