nixos/nextcloud: add occ internal option

This option exposes the prefconfigured nextcloud-occ
program. nextcloud-occ can then be used in other systemd services or
added in environment.systemPackages.

The nextcloud test shows how it can be add in
environment.systemPackages.

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

@@ -303,6 +303,14 @@ in {
         '';
       };
     };
+    occ = mkOption {
+      type = types.package;
+      default = occ;
+      internal = true;
+      description = ''
+        The nextcloud-occ program preconfigured to target this Nextcloud instance.
+      '';
+    };
   };
 
   config = mkIf cfg.enable (mkMerge [

nixos/tests/nextcloud/basic.nix

@@ -26,7 +26,9 @@ in {
       };
     };
 
-    nextcloud = { config, pkgs, ... }: {
+    nextcloud = { config, pkgs, ... }: let
+      cfg = config;
+    in {
       networking.firewall.allowedTCPPorts = [ 80 ];
 
       services.nextcloud = {
@@ -42,6 +44,8 @@ in {
           startAt = "20:00";
         };
       };
+
+      environment.systemPackages = [ cfg.services.nextcloud.occ ];
     };
   };
 
@@ -67,6 +71,8 @@ in {
   in ''
     start_all()
     nextcloud.wait_for_unit("multi-user.target")
+    # This is just to ensure the nextcloud-occ program is working
+    nextcloud.succeed("nextcloud-occ status")
     nextcloud.succeed("curl -sSf http://nextcloud/login")
     nextcloud.succeed(
         "${withRcloneEnv} ${copySharedFile}"