system/modules/files.nix

{ ... }:

{
  fileSystems."/mnt/share/Music" = {
    device = "//nas.local/Music";
    fsType = "cifs";
    options = let
      automount_opts = "x-systemd.automount,noauto,x-systemd.idle-timeout=60,x-systemd.device-timeout=5s,x-systemd.mount-timeout=5s";

    in ["${automount_opts},credentials=/etc/nixos/smb-secrets,uid=1000,gid=100"];
  };
}