first draft of the automesh abstraction

flake.nix

@@ -23,6 +23,7 @@
         mkLocalModsInput
         lanzaboote.nixosModules.lanzaboote
         inputs.microvm.nixosModules.host
+        ./hosts/network.nix
       ];
     };
     passInputs = {

hosts/network.nix

@@ -0,0 +1,77 @@
+{lib, ...}: let
+  prefix = "lyn";
+
+  #define wireguard subnets
+  wg_subnets = {
+    v4 = "10.35.0.1/24";
+    v6 = "fd1a:acab:cafe:1337::/64";
+  };
+
+  #Below is where all hosts are defined
+  hosts = {
+    wg-gateway = {
+      wg = {
+        enabled = true;
+        pubkey = "lol";
+        port = 51820;
+      };
+      v4 = {
+        public = "78.47.226.47";
+        # we use 10.35.0.0/16 as a range for private subnets, specifically 10.35.0.0/24 for wireguard peers
+        internal = "10.35.0.1";
+      };
+      v6 = {
+        public = "2a01:4f8:1c1b:d2db::";
+        # 1aacabcafe is the global ID and 1337 is the wireguard peer subnet ID, resulting in the ULA fd1a:acab:cafe:1337::/64
+        internal = "fd1a:acab:cafe:1337:8f4c:68cd";
+      };
+    };
+    supernova = {
+      wg = {
+        enabled = true;
+        pubkey = "lol";
+        port = 51820;
+      };
+      v4 = {
+        public = "";
+        # we use 10.35.0.0/16 as a range for private subnets, specifically 10.35.0.0/24 for wireguard peers
+        internal = "10.35.0.2";
+      };
+      v6 = {
+        public = "";
+        # 1aacabcafe is the global ID and 1337 is the wireguard peer subnet ID, resulting in the ULA fd1a:acab:cafe:1337::/64
+        internal = "fd1a:acab:cafe:1337:6722:3657";
+      };
+    };
+  };
+
+  # function to make a peerlist suitable for wgautomesh
+  buildPeerlist = version: hosts: let
+    #filter out hosts that have wg.enabled set to false
+    wgEnabledHosts = lib.filterAttrs (_: host: host.wg.enabled or false) hosts;
+    #filter out hosts that don't support IP{$version}
+    filteredHosts = lib.filterAttrs (_: host: host.${version}.public != "") wgEnabledHosts;
+  in
+    lib.mapAttrs (name: host: {
+      pubkey = host.wg.pubkey;
+      #if there is no public IP, make endpoint null so wgautomesh knows it unknown
+      endpoint =
+        if host.${version}.public == ""
+        then null
+        else host.${version}.public;
+      address = host.${version}.internal;
+    })
+    filteredHosts;
+in {
+  ${prefix}.network = {
+    IPv4 = {
+      wg_subnet = wg_subnets.v4;
+      peerlist = buildPeerlist "v4" hosts;
+    };
+    IPv6 = {
+      wg_subnet = wg_subnets.v6;
+      peerlist = buildPeerlist "v6" hosts;
+    };
+    inherit hosts;
+  };
+}

hosts/wg-gateway/default.nix

@@ -17,6 +17,9 @@
   lyn.users.lyn.enable = true;
 
   # network
+
+  lyn.services.wgautomesh.enable = true;
+
   networking.useDHCP = false;
   networking.hostName = "wg-gateway"; # Define your hostname.
   systemd.network.enable = true;

modules/services/wgautomesh.nix

@@ -0,0 +1,34 @@
+{
+  config,
+  pkgs,
+  lib,
+  cfg,
+  ...
+}: {
+  opt.useIPv6 = lib.mkOption {
+    type = lib.types.bool;
+    description = "Whether to use IPv6. Defaults to true";
+    default = true;
+  };
+  # helper vars to prettify
+  currentHost = lyn.network.hosts.${networking.hostName};
+  wireguardPort = currentHost.wg.port;
+
+  networking.wireguard.interfaces.wg0 = {
+    ips = ["${lyn.network.IPv4.wg_subnet}"];
+    listenPort = cfg.wireguardPort;
+    privateKeyFile = "/var/lib/wireguard-keys/private";
+    mtu = 1420;
+  };
+  services.wgautomesh = {
+    enable = true;
+    services.wgautomesh.settings = {
+      interface = "wg0";
+      peers =
+        if opt.useIPv6
+        then lyn.network.IPv6.peerlist
+        else lyn.network.IPv4.peerlist;
+      upnp_forward_external_port = wireguardPort;
+    };
+  };
+}