flake.nix: Move vm out of `nixosConfigurations` so that checks work

flake.nix

@@ -31,35 +31,11 @@
     ##################
     # Configurations #
     ##################
-    nixosConfigurations = let
-      # Modules that should be generic to all systems
-      genericModule = {...}: {
-        imports = [
-          # Inject flake dependencies
-          sops-nix.nixosModules.sops
-          tlaternet-webserver.nixosModules.default
-
-          # Import actual configuration
-          (import ./configuration)
-        ];
-      };
-    in {
+    nixosConfigurations = {
       # The actual system definition
-      tlaternet = nixpkgs.lib.nixosSystem {
+      tlaternet = self.lib.makeNixosSystem {
         inherit system;
-        modules = [
-          genericModule
-          (import ./configuration/hardware-specific/linode)
-        ];
-      };
-
-      # A qemu VM to test the above with
-      vm = nixpkgs.lib.nixosSystem {
-        inherit system;
-        modules = [
-          genericModule
-          (import ./configuration/hardware-specific/vm.nix)
-        ];
+        extraModules = [(import ./configuration/hardware-specific/linode)];
       };
     };
 
@@ -89,7 +65,10 @@
     ####################
     # Helper functions #
     ####################
-    lib = import ./lib {lib = nixpkgs.lib;};
+    lib = import ./lib {
+      inherit nixpkgs sops-nix tlaternet-webserver;
+      lib = nixpkgs.lib;
+    };
 
     ####################
     # VM launch script #
@@ -98,7 +77,11 @@
       inherit (nixpkgs.legacyPackages.${system}) writeShellScript;
     in {
       default = let
-        inherit (self.nixosConfigurations.vm.config.system.build) vm;
+        vm = self.lib.makeNixosSystem {
+          inherit system;
+          extraModules = [(import ./configuration/hardware-specific/vm.nix)];
+        };
+
         qemuNetOpts = self.lib.makeQemuNetOpts {
           "2222" = "2222";
           "3080" = "80";
@@ -110,7 +93,7 @@
         program = builtins.toString (writeShellScript "run-vm" ''
           export QEMU_OPTS="-m 3941 -smp 2 -display curses"
           export QEMU_NET_OPTS="${qemuNetOpts}"
-          "${vm}/bin/run-tlaternet-vm"
+          "${vm.config.system.build.vm}/bin/run-tlaternet-vm"
         '');
       };
 

lib/default.nix

@@ -1,4 +1,9 @@
-{lib}: let
+{
+  lib,
+  nixpkgs,
+  sops-nix,
+  tlaternet-webserver,
+}: let
   inherit (lib.attrsets) mapAttrsToList;
   inherit (lib.strings) concatStringsSep;
 in {
@@ -7,4 +12,19 @@ in {
     (mapAttrsToList
       (host: vm: "hostfwd=::${host}-:${vm}")
       portMapping);
+
+  makeNixosSystem = {
+    system,
+    extraModules,
+  }:
+    nixpkgs.lib.nixosSystem {
+      inherit system;
+      modules =
+        [
+          sops-nix.nixosModules.sops
+          tlaternet-webserver.nixosModules.default
+          (import ../configuration)
+        ]
+        ++ extraModules;
+    };
 }