Terraform List of Maps - terraform

Question

I currently have a single resource defined for
aws_ebs_volume & aws_volume_attachment
I use a count based on a variable to determine how many devices I want to created followed by a count on the attachment:
data_volumes = ["50"]
data_device = ["xvde"]
resource "aws_ebs_volume" "datavolumes" {
count = "${length(var.data_volumes)}"
size = "${var.data_volumes[count.index]}"
tags = "${var.instance_tags}"
encrypted = "true"
availability_zone = "us-east-2b"
kms_key_id = "${var.kms_key}"
}
resource "aws_volume_attachment" "attachvolumes" {
count = "${length(var.data_volumes)}"
device_name = "${var.data_device[count.index]}"
volume_id = "${aws_ebs_volume.datavolumes.*.id[count.index]}"
instance_id = "${aws_instance.general.id}"
}
I'm struggling with finding a way to assign unique tags to each of these volumes that get created, as you can see I'm using a static list of "instance_tags" for each of the volumes but I'd like to have unique tags applied to each of the volumes. I'm trying to avoid having to specify a resource/volume but might be easiest at this point.
Hoping someone can help me understand if its possible and an example of what it looks like.

Answer 1

I think I found an approach that works for what I'm trying to accomplish:
resource "aws_ebs_volume" "datavolumes" {
count = "${length(var.data_volumes)}"
size = "${var.data_volumes[count.index]}"
tags = "${merge(
var.instance_tags,
map(
"DriveLetter", "${var.data_letters[count.index]}",
"DriveLabel", "${var.data_labels[count.index]}"
)
)}"
data_volumes = ["50","50","50"]
data_device = ["xvde","xvdf","xvdg"]
data_letters = ["E:", "F:", "G:"]
data_labels = ["Data", "Logs", "TempDB"]
This gives me unique EBS volumes with Unique tag properties for each volumes and maintains my single resource