nixos/lxd: use networkd for DHCP/RA

Enables networkd instead of dhcpcd for DHCP/RA. It offers a solid base
for network configuration, that is much more extensible than dhcpcd and
also better maintained than our bespoke `networking.interfaces` modules.

Closes: #287269

2 files changed, 32 insertions, 4 deletions

diff --git a/nixos/maintainers/scripts/lxd/lxd-virtual-machine-image-inner.nix b/nixos/maintainers/scripts/lxd/lxd-virtual-machine-image-inner.nix
index c1c50b32ff5b..2d1761401fcd 100644
--- a/nixos/maintainers/scripts/lxd/lxd-virtual-machine-image-inner.nix
+++ b/nixos/maintainers/scripts/lxd/lxd-virtual-machine-image-inner.nix
@@ -13,8 +13,22 @@
       ./lxd.nix
     ];
 
-  networking.useDHCP = false;
-  networking.interfaces.eth0.useDHCP = true;
+  networking = {
+    dhcdpcd.enable = false;
+    useDHCP = false;
+  };
+
+  systemd.network = {
+    enable = true;
+    networks."50-eth0" = {
+      matchConfig.Name = "eth0";
+      networkConfig = {
+        DHCP = "ipv4";
+        IPv6AcceptRA = true;
+      };
+      linkConfig.RequiredForOnline = "routable";
+    };
+  };
 
   system.stateVersion = "@stateVersion@"; # Did you read the comment?
 }
diff --git a/nixos/maintainers/scripts/lxd/lxd-virtual-machine-image.nix b/nixos/maintainers/scripts/lxd/lxd-virtual-machine-image.nix
index 0d96eea0e2d2..a58579914465 100644
--- a/nixos/maintainers/scripts/lxd/lxd-virtual-machine-image.nix
+++ b/nixos/maintainers/scripts/lxd/lxd-virtual-machine-image.nix
@@ -26,6 +26,20 @@
   '';
 
   # Network
-  networking.useDHCP = false;
-  networking.interfaces.enp5s0.useDHCP = true;
+  networking = {
+    dhcdpcd.enable = false;
+    useDHCP = false;
+  };
+
+  systemd.network = {
+    enable = true;
+    networks."50-enp5s0" = {
+      matchConfig.Name = "enp5s0";
+      networkConfig = {
+        DHCP = "ipv4";
+        IPv6AcceptRA = true;
+      };
+      linkConfig.RequiredForOnline = "routable";
+    };
+  };
 }