Terraform : The "each" object does not support this operation - google-cloud-platform

Question

I'm trying to create "Parent" and "Child" resources with Terraform, from a variable like this:
variable "tags" {
default = {
parent1 = ["child1", "child2"]
parent2 = ["child2", "child4", "child5"]
}
}
For each key in my variable I want to create a Parent resource, which I do and works fine:
resource "google_tags_tag_key" "parent" {
for_each = toset(keys(var.tags))
parent = "organizations/1234567890"
short_name = each.key
description = ""
}
My problem is regarding child resources ... For each item in a list, I want to create a child resource. But I can't seem to do a nested loop on the "for_each" argument.
So I tried to use the "setproduct" function to flatten my variable. as follows.
locals {
helper_list = [for k, v in var.tags:
setproduct(list(k), v)
]
}
This is a workaround, but despite everything, I still cannot resolve my problem by trying in the following way.
resource "google_tags_tag_value" "child" {
for_each = local.helper_list
parent = "tagKeys/${google_tags_tag_key.parent[each.0]}"
short_name = each.1
description = ""
}
This returns the folling error: The "each" object does not support this operation.
How can I solve my problem by going through a helper_list or without?

Answer 1

I would do this as follows:
variable "tags" {
default = {
parent1 = ["child1", "child2"]
parent2 = ["child2", "child4", "child5"]
}
}
locals {
# construct flat map
helper_map = merge([
for parent, children in var.tags:
{
for child in children:
"${parent}-${child}" => {
"parent" = parent
"child" = child
}
}
]...)
}
output "helper_map" {
value = local.helper_map
}
which gives:
helper_map = {
"parent1-child1" = {
"child" = "child1"
"parent" = "parent1"
}
"parent1-child2" = {
"child" = "child2"
"parent" = "parent1"
}
"parent2-child2" = {
"child" = "child2"
"parent" = "parent2"
}
"parent2-child4" = {
"child" = "child4"
"parent" = "parent2"
}
"parent2-child5" = {
"child" = "child5"
"parent" = "parent2"
}
}
Then you can do, assuming I understand your desired outcome:
resource "google_tags_tag_value" "child" {
for_each = local.helper_map
parent = "tagKeys/${google_tags_tag_key.parent[each.value.parent]}"
short_name = each.value.child
description = ""
}