Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.
ntopng is a high-speed web-based traffic analysis and flow collection
tool. Enable it by adding this to configuration.nix:
services.ntopng.enable = true;
Open a browser at http://localhost:3000 and login with the default
username/password: admin/admin.