nixos/virtualisation: add option for explicitly named network interfaces

Adds a new option to the virtualisation modules that enables specifying
explicitly named network interfaces in QEMU VMs. The existing
`virtualisation.vlans` is still supported for cases where the name of
the network interface is irrelevant.

1 files changed, 31 insertions, 1 deletions

diff --git a/nixos/modules/virtualisation/qemu-vm.nix b/nixos/modules/virtualisation/qemu-vm.nix
index 4520408ca3379..6f03f9e83b362 100644
--- a/nixos/modules/virtualisation/qemu-vm.nix
+++ b/nixos/modules/virtualisation/qemu-vm.nix
@@ -545,7 +545,8 @@ in
     virtualisation.vlans =
       mkOption {
         type = types.listOf types.ints.unsigned;
-        default = [ 1 ];
+        default = if config.virtualisation.interfaces == {} then [ 1 ] else [ ];
+        defaultText = lib.literalExpression ''if config.virtualisation.interfaces == {} then [ 1 ] else [ ]'';
         example = [ 1 2 ];
         description =
           lib.mdDoc ''
@@ -560,6 +561,35 @@ in
           '';
       };
 
+    virtualisation.interfaces = mkOption {
+      default = {};
+      example = {
+        enp1s0.vlan = 1;
+      };
+      description = lib.mdDoc ''
+        Network interfaces to add to the VM.
+      '';
+      type = with types; attrsOf (submodule {
+        options = {
+          vlan = mkOption {
+            type = types.ints.unsigned;
+            description = lib.mdDoc ''
+              VLAN to which the network interface is connected.
+            '';
+          };
+
+          assignIP = mkOption {
+            type = types.bool;
+            default = false;
+            description = lib.mdDoc ''
+              Automatically assign an IP address to the network interface using the same scheme as
+              virtualisation.vlans.
+            '';
+          };
+        };
+      });
+    };
+
     virtualisation.writableStore =
       mkOption {
         type = types.bool;