Terraform assign volume to AWS instances list - amazon-web-services

Question

I have created a AWS instance list using Terraform:
resource "aws_instance" "masters" {
count = 2
ami = "${var.aws_centos_ami}"
instance_type = "t2.micro"
availability_zone = "eu-west-1b"
tags {
Name = "master-${count.index}"
}
}
How can I assign volumes to that instances like in a loop?
I just trying using the next:
data "aws_ebs_volume" "masters_ebs_volume" {
most_recent = true
filter {
name = "attachment.instance-id"
values = ["${aws_instance.masters.*.id}"]
}
}
But I don't thing it is working fine, because when I try to write the AWS volumes in a file, it writes only one volume name.
provisioner "local-exec" {
command = "echo \"${join("\n", data.aws_ebs_volume.masters_ebs_volume.*.id)}\" >> volumes"
}
I have tried defining the volume like this:
data "aws_ebs_volume" "masters_ebs_volume" {
count = 2
# most_recent = true
filter {
name = "attachment.instance-id"
values = ["${aws_instance.masters.*.id}"]
}
}
But it throws the next error:
data.aws_ebs_volume.masters_ebs_volume.0: Your query returned more than one result. Please try a more specific search criteria, or set `most_recent` attribute to true.

Answer 1

You'll need to tell it which instance specifically maps to which volume. You can do that with element():
data "aws_ebs_volume" "masters_ebs_volume" {
count = 2
filter {
name = "attachment.instance-id"
values = ["${element(aws_instance.masters.*.id, count.index)}"]
}
}