invidious: pass configuration in INVIDIOUS_CONFIG as YAML (#448855)

nixos/modules/services/web-apps/invidious.nix

@@ -7,16 +7,19 @@
 }:
 let
   cfg = config.services.invidious;
-  # To allow injecting secrets with jq, json (instead of yaml) is used
-  settingsFormat = pkgs.formats.json { };
+
   inherit (lib) types;
 
+  # This need to be JSON to reduce number of
+  # breaking changes, for backwards
+  # compatibility with pre-25.11
+  settingsFormat = pkgs.formats.json { };
   settingsFile = settingsFormat.generate "invidious-settings" cfg.settings;
 
   generatedHmacKeyFile = "/var/lib/invidious/hmac_key";
   generateHmac = cfg.hmacKeyFile == null;
 
-  commonInvidousServiceConfig = {
+  commonInvidiousServiceConfig = {
     description = "Invidious (An alternative YouTube front-end)";
     wants = [ "network-online.target" ];
     after = [ "network-online.target" ] ++ lib.optional cfg.database.createLocally "postgresql.target";
@@ -59,9 +62,51 @@ let
       RuntimeRandomizedExtraSec = lib.mkDefault "5min";
     };
   };
+
+  configScript =
+    scaleIndex:
+    ''
+      configParts=()
+    ''
+    # autogenerated hmac_key
+    + lib.optionalString generateHmac ''
+      configParts+=("$(${pkgs.jq}/bin/jq -R '{"hmac_key":.}' <"${generatedHmacKeyFile}")")
+    ''
+    # generated settings file
+    + ''
+      configParts+=("$(< ${settingsFile})")
+    ''
+    # optional database password file
+    + lib.optionalString (cfg.database.host != null) ''
+      configParts+=("$(${pkgs.jq}/bin/jq -R '{"db":{"password":.}}' ${cfg.database.passwordFile})")
+    ''
+    # optional extra settings file
+    + lib.optionalString (cfg.extraSettingsFile != null) ''
+      configParts+=("$(< ${lib.escapeShellArg cfg.extraSettingsFile})")
+    ''
+    # explicitly specified hmac key file
+    + lib.optionalString (cfg.hmacKeyFile != null) ''
+      configParts+=("$(< ${lib.escapeShellArg cfg.hmacKeyFile})")
+    ''
+    # configure threads for secondary instances
+    + lib.optionalString (scaleIndex > 0) ''
+      configParts+=('{"channel_threads":0, "feed_threads":0}')
+    ''
+    # configure different ports for the instances
+    + ''
+      configParts+=('{"port":${toString (cfg.port + scaleIndex)}}')
+    ''
+    # merge all parts into a single configuration with later elements overriding previous elements
+    + ''
+      mergedConfig="$(${pkgs.jq}/bin/jq -s 'reduce .[] as $item ({}; . * $item)' <<<"''${configParts[*]}")"
+      export INVIDIOUS_CONFIG=$(echo "$mergedConfig" | ${pkgs.yq-go}/bin/yq -P)
+
+      exec ${cfg.package}/bin/invidious
+    '';
+
   mkInvidiousService =
     scaleIndex:
-    lib.foldl' lib.recursiveUpdate commonInvidousServiceConfig [
+    lib.foldl' lib.recursiveUpdate commonInvidiousServiceConfig [
       # only generate the hmac file in the first service
       (lib.optionalAttrs (scaleIndex == 0) {
         preStart = lib.optionalString generateHmac ''
@@ -73,47 +118,10 @@ let
       })
       # configure the secondary services to run after the first service
       (lib.optionalAttrs (scaleIndex > 0) {
-        after = commonInvidousServiceConfig.after ++ [ "invidious.service" ];
-        wants = commonInvidousServiceConfig.wants ++ [ "invidious.service" ];
+        after = commonInvidiousServiceConfig.after ++ [ "invidious.service" ];
+        wants = commonInvidiousServiceConfig.wants ++ [ "invidious.service" ];
       })
-      {
-        script = ''
-          configParts=()
-        ''
-        # autogenerated hmac_key
-        + lib.optionalString generateHmac ''
-          configParts+=("$(${pkgs.jq}/bin/jq -R '{"hmac_key":.}' <"${generatedHmacKeyFile}")")
-        ''
-        # generated settings file
-        + ''
-          configParts+=("$(< ${lib.escapeShellArg settingsFile})")
-        ''
-        # optional database password file
-        + lib.optionalString (cfg.database.host != null) ''
-          configParts+=("$(${pkgs.jq}/bin/jq -R '{"db":{"password":.}}' ${lib.escapeShellArg cfg.database.passwordFile})")
-        ''
-        # optional extra settings file
-        + lib.optionalString (cfg.extraSettingsFile != null) ''
-          configParts+=("$(< ${lib.escapeShellArg cfg.extraSettingsFile})")
-        ''
-        # explicitly specified hmac key file
-        + lib.optionalString (cfg.hmacKeyFile != null) ''
-          configParts+=("$(< ${lib.escapeShellArg cfg.hmacKeyFile})")
-        ''
-        # configure threads for secondary instances
-        + lib.optionalString (scaleIndex > 0) ''
-          configParts+=('{"channel_threads":0, "feed_threads":0}')
-        ''
-        # configure different ports for the instances
-        + ''
-          configParts+=('{"port":${toString (cfg.port + scaleIndex)}}')
-        ''
-        # merge all parts into a single configuration with later elements overriding previous elements
-        + ''
-          export INVIDIOUS_CONFIG="$(${pkgs.jq}/bin/jq -s 'reduce .[] as $item ({}; . * $item)' <<<"''${configParts[*]}")"
-          exec ${cfg.package}/bin/invidious
-        '';
-      }
+      { script = configScript scaleIndex; }
     ];
 
   serviceConfig = {