nixos/lemmy: remove `services.lemmy.jwtSecretPath`

Co-authored-by: Ctem <[e-mail]>
Co-authored-by: Brian Leung <[e-mail]>
Co-authored-by: Shahar Dawn Or <[e-mail]>
Co-authored-by: Ilan Joselevich <[e-mail]>

nixos/modules/services/web-apps/lemmy.md

···
     hostname = "lemmy.union.rocks";
     database.createLocally = true;
   };
-  jwtSecretPath = "/run/secrets/lemmyJwt";
   caddy.enable = true;
 }
 ```
-
-(note that you can use something like agenix to get your secret jwt to the specified path)
 
 this will start the backend on port 8536 and the frontend on port 1234.
 It will expose your instance with a caddy reverse proxy to the hostname you've provided.

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

···
   # `pandoc lemmy.md -t docbook --top-level-division=chapter --extract-media=media -f markdown+smart > lemmy.xml`
   meta.doc = ./lemmy.xml;
 
+  imports = [
+    (mkRemovedOptionModule [ "services" "lemmy" "jwtSecretPath" ] "As of v0.13.0, Lemmy auto-generates the JWT secret.")
+  ];
+
   options.services.lemmy = {
 
     enable = mkEnableOption (lib.mdDoc "lemmy a federated alternative to reddit in rust");
-
-    jwtSecretPath = mkOption {
-      type = types.path;
-      description = lib.mdDoc "Path to read the jwt secret from.";
-    };
 
     ui = {
       port = mkOption {
···
 
         requires = lib.optionals cfg.settings.database.createLocally [ "lemmy-postgresql.service" ];
 
-        # script is needed here since loadcredential is not accessible on ExecPreStart
         script = ''
           ${pkgs.coreutils}/bin/install -m 600 ${settingsFormat.generate "config.hjson" cfg.settings} /run/lemmy/config.hjson
-          jwtSecret="$(< $CREDENTIALS_DIRECTORY/jwt_secret )"
-          ${pkgs.jq}/bin/jq ".jwt_secret = \"$jwtSecret\"" /run/lemmy/config.hjson | ${pkgs.moreutils}/bin/sponge /run/lemmy/config.hjson
           ${pkgs.lemmy-server}/bin/lemmy_server
         '';
 
         serviceConfig = {
           DynamicUser = true;
           RuntimeDirectory = "lemmy";
-          LoadCredential = "jwt_secret:${cfg.jwtSecretPath}";
         };
       };
 

nixos/modules/services/web-apps/lemmy.xml

···
     <para>
       the minimum to start lemmy is
     </para>
-    <programlisting language="bash">
+    <programlisting language="nix">
 services.lemmy = {
   enable = true;
   settings = {
     hostname = &quot;lemmy.union.rocks&quot;;
     database.createLocally = true;
   };
-  jwtSecretPath = &quot;/run/secrets/lemmyJwt&quot;;
   caddy.enable = true;
 }
 </programlisting>
-    <para>
-      (note that you can use something like agenix to get your secret
-      jwt to the specified path)
-    </para>
     <para>
       this will start the backend on port 8536 and the frontend on port
       1234. It will expose your instance with a caddy reverse proxy to

nixos/tests/lemmy.nix

···
     "${lemmyNodeName}" = {
       services.lemmy = {
         enable = true;
-        jwtSecretPath = pkgs.writeTextFile {
-          name = "lemmy-secret";
-          text = "very-secret-password123";
-        };
         ui.port = uiPort;
         settings = {
           hostname = "http://${lemmyNodeName}";