os-release: add stockholm-version-id option

1 files changed, 22 insertions, 16 deletions

diff --git a/krebs/3modules/os-release.nix b/krebs/3modules/os-release.nix
index bfd352825..929ec45d9 100644
--- a/krebs/3modules/os-release.nix
+++ b/krebs/3modules/os-release.nix
@@ -8,28 +8,34 @@ let
   nixos-version = "${nixos-version-id} (${nixos-codeName})";
   nixos-pretty-name = "NixOS ${nixos-version}";
 
-  stockholm-version-id = let
-    eval = builtins.tryEval (removeSuffix "\n" (readFile <stockholm-version>));
-  in
-    if eval.success then eval.value else "unknown";
-
-  stockholm-version = "${stockholm-version-id}";
+  stockholm-version = "${config.krebs.os-release.stockholm-version-id}";
   stockholm-pretty-name = "stockholm ${stockholm-version}";
 
   version = "${stockholm-version}/${nixos-version}";
-  version-id = "${stockholm-version-id}/${nixos-version-id}";
+  version-id = "${config.krebs.os-release.stockholm-version-id}/${nixos-version-id}";
   pretty-name = "${stockholm-pretty-name} / ${nixos-pretty-name}";
 
   home-url = http://cgit.ni.krebsco.de/stockholm;
 in
 {
-  # http://0pointer.de/public/systemd-man/os-release.html
-  environment.etc."os-release".text = mkForce ''
-    NAME="stockholm/NixOS"
-    ID=stockholm
-    VERSION="${version}"
-    VERSION_ID="${version-id}"
-    PRETTY_NAME="${pretty-name}"
-    HOME_URL="${home-url}"
-  '';
+  options.krebs.os-release = {
+    stockholm-version-id = lib.mkOption {
+      type = lib.types.str;
+      default = let
+          eval = builtins.tryEval (removeSuffix "\n" (readFile <stockholm-version>));
+        in
+          if eval.success then eval.value else "unknown";
+    };
+  };
+  config = {
+    # http://0pointer.de/public/systemd-man/os-release.html
+    environment.etc."os-release".text = mkForce ''
+      NAME="stockholm/NixOS"
+      ID=stockholm
+      VERSION="${version}"
+      VERSION_ID="${version-id}"
+      PRETTY_NAME="${pretty-name}"
+      HOME_URL="${home-url}"
+    '';
+  };
 }