nixos/soju: add sojuctl wrapper with config path

The config is a in an arbitrary nix store path, and is necessary to
invoke sojuctl. Without the wrapper, you have to read the systemd unit
or use a similar trick to find it.

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

@@ -376,6 +376,8 @@ The module update takes care of the new config syntax and the data itself (user
 
 - `services.soju` now has the option `adminSocket.enable`. This option defaults to `true`, and creates a unix admin socket at `/run/soju/admin`.
 
+- `services.soju` now includes a wrapper for the `sojuctl` command, pointed at the service config file.
+
 
 ## Nixpkgs internals {#sec-release-23.11-nixpkgs-internals}
 

nixos/modules/services/networking/soju.nix

@@ -25,6 +25,10 @@ let
 
     ${cfg.extraConfig}
   '';
+
+  sojuctl = pkgs.writeShellScriptBin "sojuctl" ''
+    exec ${pkgs.soju}/bin/sojuctl --config ${configFile} "$@"
+  '';
 in
 {
   ###### interface
@@ -118,6 +122,8 @@ in
       }
     ];
 
+    environment.systemPackages = [ sojuctl ];
+
     systemd.services.soju = {
       description = "soju IRC bouncer";
       wantedBy = [ "multi-user.target" ];