nixos: add system.switch.enable flag

This flag allows the user to optionally exclude
switch-to-confguration.pl from toplevel.

This is interesting for appliance images where you don't want to re-build
the system. This flag is called `rebuildable` because the standard
interface to do this is `nixos-rebuild` which will not work anymore with
this change.

1 files changed, 15 insertions, 0 deletions

diff --git a/nixos/tests/non-switchable-system.nix b/nixos/tests/non-switchable-system.nix
new file mode 100644
index 0000000000000..54bede75453ba
--- /dev/null
+++ b/nixos/tests/non-switchable-system.nix
@@ -0,0 +1,15 @@
+{ lib, ... }:
+
+{
+  name = "non-switchable-system";
+
+  meta.maintainers = with lib.maintainers; [ nikstur ];
+
+  nodes.machine = {
+    system.switch.enable = false;
+  };
+
+  testScript = ''
+    machine.succeed("test ! -e /run/current-system/bin/switch-to-configuration")
+  '';
+}