gistfile1.txt

{ config, ... }:
{
  sops.secrets.service-password = {};
  containers.myService =
  let
    passwordFile = config.sops.secrets.service-password.path;
  in
  {
    config = { config, ... }: {
      systemd.services.myService = {
        serviceConfig = {
          Environment="PASSWORDFILE=${passwordFile}";
        };
      };
    };
  };
}