ctucx.git: travelynx2fedi

nixosModule: generate configFile from attrset :)

diff --git a/nixosModule.nix b/nixosModule.nix
@@ -4,7 +4,8 @@ with lib;
 
 let
   cfg            = config.services.travelynx2fedi;
-  settingsFormat = pkgs.formats.json {};
+  settingsFormat = pkgs.formats.ini {};
+  configFile     = settingsFormat.generate "config.ini" cfg.config;
 
 in {
 

@@ -36,9 +37,21 @@ in {
         default  = 8321;
       };
 
-      configFile = mkOption {
-        type     = types.str;
-        default  = "/var/lib/travelynx2fedi/config.ini";
+      config = mkOption {
+        type    = settingsFormat.type;
+        default = {};
+        example = {};
+      };
+
+      environmentFiles = mkOption {
+        type = types.listOf types.path;
+        default = [];
+        example = [ "/run/keys/travelynx2fedi.env" ];
+        description = lib.mdDoc ''
+          File to load as environment file. Environment variables from this file
+          will be interpolated into the config file using envsubst.
+          This is useful to avoid putting secrets into the nix store.
+        '';
       };
 
     };

@@ -61,19 +74,33 @@ in {
 
       environment = {
         TRAVELYNX2FEDI_PORT         = builtins.toString cfg.port;
-        TRAVELYNX2FEDI_CONFIG_PATH  = cfg.configFile;
+        TRAVELYNX2FEDI_CONFIG_PATH  = (
+          if cfg.environmentFiles == []
+          then configFile
+          else "/var/run/travelynx2fedi/config.ini"
+        );
       };
 
       serviceConfig = {
         DynamicUser = true;
 
         Type = "exec";
+
+        RuntimeDirectory   = "travelynx2fedi";
         StateDirectory     = "travelynx2fedi";
         StateDirectoryMode = "750";
 
+        EnvironmentFile = cfg.environmentFiles;
+
+        
         Restart    = "always";
         RestartSec = 3;
 
+        ExecStartPre = lib.optional (cfg.environmentFiles != []) (pkgs.writeShellScript "travelynx2fedi-preStart" ''
+          umask 077
+          ${pkgs.envsubst}/bin/envsubst -i "${configFile}" > /var/run/travelynx2fedi/config.ini
+        '');
+
         ExecStart = "${cfg.package}/bin/travelynx2fedi";
 
         NoNewPrivileges = true;