id := m.ID("foo")
	if *id != 101 {
		t.Fatalf("expected: id=%d; got: id=%d", 101, *id)
	}
	id = m.ID("bar")
	if id != nil {
		t.Fatalf("expected nil for unknown entry")
	}
}

func TestAddUsersAndGroupsImpl(t *testing.T) {
	const (
		loginDef       = "SYS_UID_MIN 101\nSYS_UID_MAX 998\nSYS_GID_MIN 102\nSYS_GID_MAX 999\n"
		passwd         = "root:x:0:0:::/bin/bash\nkubeadm-etcd:x:101:102:::/bin/false\n"