logrotate: add services.logrotate.configFile escape hatch

nixos/modules/services/logging/logrotate.nix

@@ -122,6 +122,27 @@ in
         defaultText = literalExpression "cfg.paths != {}";
       };
 
+      configFile = mkOption {
+        type = types.path;
+        default = configFile;
+        defaultText = ''
+          A configuration file automatically generated by NixOS.
+        '';
+        description = ''
+          Override the configuration file used by MySQL. By default,
+          NixOS generates one automatically from <option>services.logrotate.settings</option>.
+        '';
+        example = literalExpression ''
+          pkgs.writeText "logrotate.conf" '''
+            missingok
+            "/var/log/*.log" {
+              rotate 4
+              weekly
+            }
+          ''';
+        '';
+      };
+
       paths = mkOption {
         type = with types; attrsOf (submodule pathOpts);
         default = { };
@@ -181,7 +202,7 @@ in
       serviceConfig = {
         Restart = "no";
         User = "root";
-        ExecStart = "${pkgs.logrotate}/sbin/logrotate ${mailOption} ${configFile}";
+        ExecStart = "${pkgs.logrotate}/sbin/logrotate ${mailOption} ${cfg.configFile}";
       };
     };
   };