nixos/klogd: remove

This module only has an effect for ancient kernel versions we don't
support.

nixos/doc/manual/from_md/release-notes/rl-2205.section.xml

@@ -432,6 +432,12 @@
           new versions will release.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          <literal>security.klogd</literal> was removed. Logging of
+          kernel messages is handled by systemd since Linux 3.5.
+        </para>
+      </listitem>
       <listitem>
         <para>
           <literal>services.kubernetes.addons.dashboard</literal> was

nixos/doc/manual/release-notes/rl-2205.section.md

@@ -141,6 +141,9 @@ In addition to numerous new and upgraded packages, this release has the followin
   org-contrib, refer to the ones in `pkgs.emacsPackages.elpaPackages` and
   `pkgs.emacsPackages.nongnuPackages` where the new versions will release.
 
+- `security.klogd` was removed.  Logging of kernel messages is handled
+  by systemd since Linux 3.5.
+
 - `services.kubernetes.addons.dashboard` was removed due to it being an outdated version.
 
 - `services.kubernetes.scheduler.{port,address}` now set `--secure-port` and `--bind-address` instead of `--port` and `--address`, since the former have been deprecated and are no longer functional in kubernetes>=1.23. Ensure that you are not relying on the insecure behaviour before upgrading.

nixos/modules/services/logging/klogd.nix

@@ -1,38 +1,9 @@
-{ config, lib, pkgs, ... }:
-
-with lib;
+{ lib, ... }:
 
 {
-  ###### interface
-
-  options = {
-
-    services.klogd.enable = mkOption {
-      type = types.bool;
-      default = versionOlder (getVersion config.boot.kernelPackages.kernel) "3.5";
-      defaultText = literalExpression ''versionOlder (getVersion config.boot.kernelPackages.kernel) "3.5"'';
-      description = ''
-        Whether to enable klogd, the kernel log message processing
-        daemon.  Since systemd handles logging of kernel messages on
-        Linux 3.5 and later, this is only useful if you're running an
-        older kernel.
-      '';
-    };
-
-  };
-
-
-  ###### implementation
-
-  config = mkIf config.services.klogd.enable {
-    systemd.services.klogd = {
-      description = "Kernel Log Daemon";
-      wantedBy = [ "multi-user.target" ];
-      path = [ pkgs.sysklogd ];
-      unitConfig.ConditionVirtualization = "!systemd-nspawn";
-      script =
-        "klogd -c 1 -2 -n " +
-        "-k $(dirname $(readlink -f /run/booted-system/kernel))/System.map";
-    };
-  };
+  imports = [
+    (lib.mkRemovedOptionModule [ "security" "klogd" "enable" ] ''
+      Logging of kernel messages is now handled by systemd.
+    '')
+  ];
 }