data "aws_subnet_ids" "private" {
  vpc_id = "vpc-05ecf2b49733444fb"

  filter {
    name   = "tag:Name"
    values = ["subnet-private-1a", "subnet-private-1b", "subnet-private-1c"]
  }
}

data "aws_subnet" "private" {
  count = "${length(data.aws_subnet_ids.private.ids)}"
  id    = "${tolist(data.aws_subnet_ids.private.ids)[count.index]}"
}


  subnet_id                   = "${data.aws_subnet.private[count.index].tags.Name}" # subnet-private-1c