在 Terraform 中，如何从列表中获取 output 的值？

Question

I am trying to get the output to show me the names of the IAM users being created.

resource "aws_iam_user" "lb" {
    name = var.elb_names[count.index]
    count = 3
    path = "/system/"
}

variable "elb_names" {
    type = list
    default = ["dev-lb", "qa-lb", "prod-lb"]
}

output "elb_names" {
    value = aws_iam_user.lb.name[count.index]
}

I expect to get the following as output

1. dev-lb
2. qa-lb
3. prod-lb

But I am getting this error...

Error: Missing resource instance key
on countEC2.tf line 38, in output "elb_names":
38:     value = aws_iam_user.lb.name[count.index]

Because aws_iam_user.lb has "count" set, its attributes must be accessed on specific instances.

For example, to correlate with indices of a referring resource, use:
aws_iam_user.lb[count.index]

Answer 1

You would have to use a slightly different approach:

output "elb_names" {
    value = aws_iam_user.lb[*].name
}

This is the splat expression [1]. Note that the output will be a list.

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[1] https://developer.hashicorp.com/terraform/language/expressions/splat