modularize system config

modules/system/network.nix

@@ -0,0 +1,52 @@
+{ pkgs, wol, ... }: {
+  boot = {
+    kernelModules = [
+      "rndis_host"
+      "cdc_ether"
+    ];
+    kernel.sysctl = {
+      "net.ipv4.ip_forward" = 1;
+      "net.ipv6.conf.all.forwarding" = 1;
+    };
+  };
+
+  networking = {
+    networkmanager.enable = true;
+    firewall.enable = false;
+    nameservers = [
+      "1.1.1.1"
+      "1.0.0.1"
+    ];
+  };
+
+  systemd.services."wol" = {
+    enable = wol != "";
+    description = "Wake-on-LAN for ${wol}";
+    requires = [ "network.target" ];
+    after = [ "network.target" ];
+    serviceConfig = {
+      ExecStart = "${pkgs.ethtool}/bin/ethtool -s ${wol} wol g";
+      Type = "oneshot";
+    };
+    wantedBy = [
+      # just in case
+      "multi-user.target"
+      "sleep.target"
+      "suspend.target"
+      "hibernate.target"
+      "hybrid-sleep.target"
+      "shutdown.target"
+      "reboot.target"
+      "halt.target"
+    ];
+  };
+
+  services = {
+    avahi = {
+      enable = true;
+      nssmdns4 = true;
+    };
+    cloudflare-warp.enable = true;
+    resolved.enable = true;
+  };
+}