Merge pull request #240325 from 999eagle/update/searxng

nixos/searx: add configuration for redis and limiter settings

nixos/doc/manual/release-notes/rl-2311.section.md

···
   - If [`system.stateVersion`](#opt-system.stateVersion) is >=23.05, `pkgs.nextcloud26` will be installed by default.
   - Please note that an upgrade from v25 (or older) to v27 directly is not possible. Please upgrade to `nextcloud26` (or earlier) first. Nextcloud prohibits skipping major versions while upgrading. You can upgrade by declaring [`services.nextcloud.package = pkgs.nextcloud26;`](options.html#opt-services.nextcloud.package).
 
+- New options were added to `services.searx` for better SearXNG support, including options for the built-in rate limiter and bot protection and automatically configuring a local redis server.
+
 - A new option was added to the virtualisation module that enables specifying explicitly named network interfaces in QEMU VMs. The existing `virtualisation.vlans` is still supported for cases where the name of the network interface is irrelevant.
 
 - DocBook option documentation is no longer supported, all module documentation now uses markdown.

nixos/modules/services/networking/searx.nix

···
   settingsFile = pkgs.writeText "settings.yml"
     (builtins.toJSON cfg.settings);
 
+  limiterSettingsFile = (pkgs.formats.toml { }).generate "limiter.toml" cfg.limiterSettings;
+
   generateConfig = ''
     cd ${runDir}
 
···
         '';
       };
 
+      redisCreateLocally = mkOption {
+        type = types.bool;
+        default = false;
+        description = lib.mdDoc ''
+          Configure a local Redis server for SearXNG. This is required if you
+          want to enable the rate limiter and bot protection of SearXNG.
+        '';
+      };
+
       settings = mkOption {
         type = types.attrsOf settingType;
         default = { };
···
         '';
       };
 
+      limiterSettings = mkOption {
+        type = types.attrsOf settingType;
+        default = { };
+        example = literalExpression ''
+          {
+            real_ip = {
+              x_for = 1;
+              ipv4_prefix = 32;
+              ipv6_prefix = 56;
+            }
+            botdetection.ip_lists.block_ip = [
+              # "93.184.216.34" # example.org
+            ];
+          }
+        '';
+        description = lib.mdDoc ''
+          Limiter settings for SearXNG.
+
+          ::: {.note}
+          For available settings, see the SearXNG
+          [schema file](https://github.com/searxng/searxng/blob/master/searx/botdetection/limiter.toml).
+          :::
+        '';
+      };
+
       package = mkOption {
         type = types.package;
         default = pkgs.searx;
···
   ###### implementation
 
   config = mkIf cfg.enable {
+    assertions = [
+      {
+        assertion = (cfg.limiterSettings != { }) -> cfg.package.pname == "searxng";
+        message = "services.searx.limiterSettings requires services.searx.package to be searxng.";
+      }
+      {
+        assertion = cfg.redisCreateLocally -> cfg.package.pname == "searxng";
+        message = "services.searx.redisCreateLocally requires services.searx.package to be searxng.";
+      }
+    ];
+
     environment.systemPackages = [ cfg.package ];
 
     users.users.searx =
···
     services.searx.settings = {
       # merge NixOS settings with defaults settings.yml
       use_default_settings = mkDefault true;
+      redis.url = lib.mkIf cfg.redisCreateLocally "unix://${config.services.redis.servers.searx.unixSocket}";
     };
 
     services.uwsgi = mkIf (cfg.runInUwsgi) {
···
       } // cfg.uwsgiConfig;
     };
 
+    services.redis.servers.searx = lib.mkIf cfg.redisCreateLocally {
+      enable = true;
+      user = "searx";
+      port = 0;
+    };
+
+    environment.etc."searxng/limiter.toml" = lib.mkIf (cfg.limiterSettings != { }) {
+      source = limiterSettingsFile;
+    };
   };
 
-  meta.maintainers = with maintainers; [ rnhmjoj ];
+  meta.maintainers = with maintainers; [ rnhmjoj _999eagle ];
 }