From 5563d1be460f5f1d6a6395708e0e49560df34db7 Mon Sep 17 00:00:00 2001
From: Jack O'Sullivan <jackos1998@gmail.com>
Date: Thu, 12 May 2022 21:06:46 +0100
Subject: [PATCH] nixos/vms: Add UUID and MAC address options

---
 devshell/commands.nix  | 6 ++++++
 nixos/boxes/colony.nix | 3 ++-
 nixos/modules/vms.nix  | 5 ++++-
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/devshell/commands.nix b/devshell/commands.nix
index fc069f3..1284185 100644
--- a/devshell/commands.nix
+++ b/devshell/commands.nix
@@ -42,6 +42,12 @@ in
       help = pkgs.agenix.meta.description;
       command = ''exec ${pkgs.agenix}/bin/agenix --identity "$PRJ_ROOT/.keys/dev.key" "$@"'';
     }
+    {
+      name = "qemu-genmac";
+      category = "utilities";
+      help = "Generate MAC address suitable for QEMU";
+      command = ''printf "52:54:00:ab:%02x:%02x\n" $((RANDOM%256)) $((RANDOM%256))'';
+    }
 
     {
       name = "fmt";
diff --git a/nixos/boxes/colony.nix b/nixos/boxes/colony.nix
index 59f483b..3be6339 100644
--- a/nixos/boxes/colony.nix
+++ b/nixos/boxes/colony.nix
@@ -39,7 +39,8 @@
           };
           vms = {
             instances.test = {
-              networks.virtual = {};
+              uuid = "59f51efb-7e6d-477b-a263-ed9620dbc87b";
+              networks.virtual.mac = "52:54:00:ab:f1:52";
               drives = {
                 disk = {
                   backend = {
diff --git a/nixos/modules/vms.nix b/nixos/modules/vms.nix
index 71c6c08..d375b47 100644
--- a/nixos/modules/vms.nix
+++ b/nixos/modules/vms.nix
@@ -44,6 +44,7 @@ let
     options = {
       bridge = mkOpt' str name "Network bridge to connect to.";
       model = mkOpt' str "virtio-net" "Device type for network interface.";
+      mac = mkOpt' str null "Guest MAC address.";
       extraOptions = mkOpt' qemuOpts { } "Extra QEMU options to set for the NIC.";
     };
   };
@@ -70,6 +71,7 @@ let
         timeout = mkOpt' ints.unsigned 30 "Clean shutdown timeout (in seconds).";
       };
 
+      uuid = mkOpt' str null "QEMU machine UUID.";
       machine = mkOpt' str "q35" "QEMU machine type.";
       enableKVM = mkBoolOpt' true "Whether to enable KVM.";
       enableUEFI = mkBoolOpt' true "Whether to enable UEFI.";
@@ -92,6 +94,7 @@ let
       i.qemuFlags ++
       [
         "name ${n}"
+        "uuid ${i.uuid}"
         "machine ${i.machine}"
         "cpu ${i.cpu}"
         "smp cpus=${toString i.smp.cpus},threads=${toString i.smp.threads}"
@@ -113,7 +116,7 @@ let
       (optional i.spice.enable "spice unix=on,addr=/run/vms/${n}/spice.sock,disable-ticketing=on") ++
       (flatten (mapAttrsToList (nn: c: [
         "netdev bridge,id=${nn},br=${c.bridge}"
-        ("device ${c.model},netdev=${nn}" + (extraQEMUOpts c.extraOptions))
+        ("device ${c.model},netdev=${nn},mac=${c.mac}" + (extraQEMUOpts c.extraOptions))
       ]) i.networks)) ++
       (flatten (mapAttrsToList (dn: c: [
         "blockdev node-name=${dn}-backend,${c.backend}"