From 1e94e891b213bb045aa75579cd6018c8fbcc4a58 Mon Sep 17 00:00:00 2001
From: Erik Arvstedt <erik.arvstedt@gmail.com>
Date: Wed, 1 Jun 2022 21:31:33 +0200
Subject: [PATCH] flake: move VM to separate file

This simplifies the flake.
---
 examples/qemu-vm/minimal-vm.nix | 35 +++++++++++++++++++++++++++++
 flake.nix                       | 40 +++++----------------------------
 2 files changed, 40 insertions(+), 35 deletions(-)
 create mode 100644 examples/qemu-vm/minimal-vm.nix

diff --git a/examples/qemu-vm/minimal-vm.nix b/examples/qemu-vm/minimal-vm.nix
new file mode 100644
index 0000000..041a310
--- /dev/null
+++ b/examples/qemu-vm/minimal-vm.nix
@@ -0,0 +1,35 @@
+nix-bitcoin: pkgs: system:
+
+rec {
+  inherit (nix-bitcoin.inputs) nixpkgs;
+
+  mkVMScript = vm: pkgs.writers.writeBash "run-vm" ''
+    set -euo pipefail
+    export TMPDIR=$(mktemp -d /tmp/nix-bitcoin-vm.XXX)
+    trap "rm -rf $TMPDIR" EXIT
+    export NIX_DISK_IMAGE=$TMPDIR/nixos.qcow2
+    QEMU_OPTS="-smp $(nproc) -m 1500" ${vm}/bin/run-*-vm
+  '';
+
+  vm = (import "${nixpkgs}/nixos" {
+    inherit system;
+    configuration = {
+      imports = [
+        nix-bitcoin.nixosModules.default
+        "${nix-bitcoin}/modules/presets/secure-node.nix"
+      ];
+
+      nix-bitcoin.generateSecrets = true;
+      services.clightning.enable = true;
+      # For faster startup in offline VMs
+      services.clightning.extraConfig = "disable-dns";
+
+      nixpkgs.pkgs = pkgs;
+      virtualisation.graphics = false;
+      services.getty.autologinUser = "root";
+      nix.nixPath = [ "nixpkgs=${nixpkgs}" ];
+    };
+  }).vm;
+
+  runVM = mkVMScript vm;
+}
diff --git a/flake.nix b/flake.nix
index 22767d3..338bce1 100644
--- a/flake.nix
+++ b/flake.nix
@@ -66,46 +66,16 @@
     } // (flake-utils.lib.eachSystem supportedSystems (system:
       let
         pkgs = nixpkgs.legacyPackages.${system};
-
         nbPkgs = self.lib.mkNbPkgs { inherit system pkgs; };
-
-        mkVMScript = vm: pkgs.writers.writeBash "run-vm" ''
-          set -euo pipefail
-          export TMPDIR=$(mktemp -d /tmp/nix-bitcoin-vm.XXX)
-          trap "rm -rf $TMPDIR" EXIT
-          export NIX_DISK_IMAGE=$TMPDIR/nixos.qcow2
-          QEMU_OPTS="-smp $(nproc) -m 1500" ${vm}/bin/run-*-vm
-        '';
       in rec {
         packages = flake-utils.lib.flattenTree (removeAttrs nbPkgs [
           "pinned" "modulesPkgs" "nixops19_09" "krops" "generate-secrets" "netns-exec"
         ]) // {
-          runVM = mkVMScript packages.vm;
-
-          # This is a simple demo VM.
-          # See ./examples/flakes/flake.nix on how to use nix-bitcoin with flakes.
-          vm = let
-            nix-bitcoin = self;
-          in
-            (import "${nixpkgs}/nixos" {
-              inherit system;
-              configuration = {
-                imports = [
-                  nix-bitcoin.nixosModules.default
-                  "${nix-bitcoin}/modules/presets/secure-node.nix"
-                ];
-
-                nix-bitcoin.generateSecrets = true;
-                services.clightning.enable = true;
-                # For faster startup in offline VMs
-                services.clightning.extraConfig = "disable-dns";
-
-                nixpkgs.pkgs = pkgs;
-                virtualisation.graphics = false;
-                services.getty.autologinUser = "root";
-                nix.nixPath = [ "nixpkgs=${nixpkgs}" ];
-              };
-            }).vm;
+          inherit (import ./examples/qemu-vm/minimal-vm.nix self pkgs system)
+            # A simple demo VM.
+            # See ./examples/flakes/flake.nix on how to use nix-bitcoin with flakes.
+            runVM
+            vm;
         };
 
         # Allow accessing the whole nested `nbPkgs` attrset (including `modulesPkgs`)