vars: new option prompts.<name>.createFile

nixosModules/clanCore/vars/generator.nix

@@ -4,13 +4,32 @@
   pkgs,
   ...
 }:
+let
+  inherit (lib)
+    attrNames
+    concatMapStrings
+    genAttrs
+    filterAttrs
+    makeBinPath
+    mkOptionDefault
+    optionalString
+    ;
+
+  promptToFile = name: ''
+    cat "$prompts/${name}" > "$out/${name}"
+  '';
+
+  promptsToFilesScript = concatMapStrings promptToFile;
+
+  filePromptNames = attrNames (filterAttrs (_name: prompt: prompt.createFile) config.prompts);
+in
 {
-  finalScript = lib.mkOptionDefault ''
+  finalScript = mkOptionDefault ''
     set -eu -o pipefail
 
-    export PATH="${lib.makeBinPath config.runtimeInputs}:${pkgs.coreutils}/bin"
+    export PATH="${makeBinPath config.runtimeInputs}:${pkgs.coreutils}/bin"
 
-    ${lib.optionalString (pkgs.stdenv.hostPlatform.isLinux) ''
+    ${optionalString (pkgs.stdenv.hostPlatform.isLinux) ''
       # prepare sandbox user on platforms where this is supported
       mkdir -p /etc
 
@@ -31,6 +50,9 @@
       ::1 localhost
       EOF
     ''}
+    ${promptsToFilesScript filePromptNames}
     ${config.script}
   '';
+
+  files = genAttrs filePromptNames (_name: { });
 }

nixosModules/clanCore/vars/interface.nix

@@ -120,6 +120,21 @@ in
               type = attrsOf (
                 submodule (prompt: {
                   options = options {
+                    createFile = {
+                      description = ''
+                        Whether the prompted value should be stored in a file with the same name as the prompt.
+
+                        If enabled, the behavior is equivalent to the following configuration:
+                        ```nix
+                        {
+                          files.<name>.secret = true;
+                          script = "cp $prompts/<name> $out/<name>";
+                        }
+                        ```
+                      '';
+                      type = bool;
+                      default = true;
+                    };
                     description = {
                       description = ''
                         The description of the prompted value
@@ -165,6 +180,7 @@ in
                 The script should produce the files specified in the 'files' attribute under $out.
               '';
               type = either str path;
+              default = "";
             };
             finalScript = {
               description = ''