{ config, lib, ... }: let
    inherit (builtins) toJSON;
    inherit (lib.options) mkOption;
    inherit (lib.types) port;
    cfg = config.services.promtail;
in {
    options.services.promtail.settings = {
        httpListenPort = mkOption {
            type = port;
            description = "Port to listen on over HTTP";
            default = 9094;
        };
    };
    config.services.promtail = {
        extraFlags = [
            "--server.http-listen-port=${cfg.settings.httpListenPort}"
        ];
    };
}