refactor: centrally manage the network configuration of all hosts in homelab

feat: new host - tailscalw-gw

hosts/homelab_tailscale_gw/default.nix

@@ -0,0 +1,43 @@
+#############################################################
+#
+#  Tailscale Gateway(homelab subnet router) - a NixOS VM running on Proxmox
+#
+#############################################################
+let
+  hostName = "tailscale-gw"; # Define your hostname.
+  vars = import ../vars.nix;
+  hostAddress = vars.networking.hostAddress.${hostName};
+in {
+  imports = [
+    ./tailscale.nix
+  ];
+
+  # supported file systems, so we can mount any removable disks with these filesystems
+  boot.supportedFilesystems = [
+    "ext4"
+    "btrfs"
+    "xfs"
+    "fat"
+    "vfat"
+    "exfat"
+  ];
+
+  networking = {
+    inherit hostName;
+    inherit (vars.networking) defaultGateway nameservers;
+
+    networkmanager.enable = false;
+    interfaces.ens18 = {
+      useDHCP = false;
+      ipv4.addresses = [hostAddress];
+    };
+  };
+
+  # This value determines the NixOS release from which the default
+  # settings for stateful data, like file locations and database versions
+  # on your system were taken. It‘s perfectly fine and recommended to leave
+  # this value at the release version of the first install of this system.
+  # Before changing this value read the documentation for this option
+  # (e.g. man configuration.nix or on https://nixos.org/nixos/options.html).
+  system.stateVersion = "23.11"; # Did you read the comment?
+}