Getting length of list from Terraform Map

I currently have this map in a test.tfvars file:

ssm =
names = ["Terraform-1","Terraform-2","Terraform-3"]
values = ["tf-1","tf-2","tf-3"]



And what I want to do is the following:

resource "aws_ssm_parameter" "parameter_store"
count = 3
name = "$$element(var.ssm[names],count.index)"
type = "String"
value = "$$element(var.ssm[values],count.index)"



But instead of count=3, I would like the count to be based off of the length of the names list from my ssm map. I've tried this:

"$length(var.ssm[names])"


But I'm getting the error:

Error: aws_ssm_parameter.parameter_store: resource count can't reference variable: names


Can anyone point me in the right direction with solving this error? I'm not too sure what I'm doing wrong.

name = "$element(var.ssm[names],count.index)"

1 Answer
1

The current terraform version (0.11.x) behaves sometimes a bit strange, when it needs to handle lists nested in a map. This might be fixed with the new version 0.12.x, but maybe there is a better solution for that...

Why do you not restructure your map like this:

ssm =
"Terraform-1" = "tf-1"
"Terraform-2" = "tf-2"
"Terraform-3" = "tf-3"



Your resource would now look like this:

resource "aws_ssm_parameter" "parameter_store"
count = "$length(var.ssm)"
name = "$keys(var.ssm, count.index)"
type = "String"
value = "$values(var.ssm, count.index)"



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