bordervm: make configurable

bordervm-configuration.nix

@@ -1,8 +1,43 @@
-{ config, pkgs, ... }:
+{ config, pkgs, lib, ... }:
-{
+let
+  cfg = config.bordervm;
+  inherit (lib) mkOption mdDoc types;
+in {
+  options.bordervm = {
+    l2tp = {
+      host = mkOption {
+        description = mdDoc ''
+          Hostname or IP address of an L2TP LNS that this VM
+          will connect to when it receives a PPPoE connection request
+        '';
+        type = types.str;
+        example = "l2tp.example.org";
+      };
+      port = mkOption {
+        description = mdDoc ''
+          Port number, if non-standard, of the LNS.
+        '';
+        type = types.int;
+        default = 1701;
+      };
+    };
+    ethernet = {
+      pciId = mkOption {
+        description = ''
+          Host PCI ID (as shown by `lspci`) of the ethernet adaptor
+          to be used by the VM. This uses VFIO and requires setup
+          on the emulation host before it will work!
+        '';
+        type = types.str;
+        example = "04:00.0";
+      };
+    };
+  };
   imports = [
     <nixpkgs/nixos/modules/virtualisation/qemu-vm.nix>
+    ./bordervm.conf.nix
   ];
+  config = {
     boot.kernelParams = [
       "loglevel=9"
     ];
@@ -11,7 +46,7 @@
         ''
       interface_name = "eth1"
       services = [ "myservice" ]
-      lns_ipaddr = "90.155.53.19:1701"
+      lns_ipaddr = "${cfg.l2tp.host}:${builtins.toString cfg.l2tp.port}"
       ac_name = "kpppoed-1.0"
     '';
       in  {
@@ -33,7 +68,7 @@
       qemu = {
         networkingOptions = [];
         options = [
-        "-device vfio-pci,host=01:00.0"
+          "-device vfio-pci,host=${cfg.ethernet.pciId}"
           "-nographic"
           "-serial mon:stdio"
         ];
@@ -67,4 +102,5 @@
       extraGroups = [ "wheel"];
     };
     services.getty.autologinUser = "liminix";
+  };
 }

bordervm.conf-example.nix

@@ -0,0 +1,9 @@
+{...}:
+{
+  bordervm = {
+    ethernet.pciId = "01:00.0";
+    l2tp = {
+      host = "l2tp.aa.net.uk";
+    };
+  };
+}