Terraform Module Count With Nested List of Maps - terraform

Question

I am attempting to loop over a module equal to the number of times a map appears inside a nested list of maps as follows:
vars.tf
variable "http_tcp_listeners" {
description = "A list of maps describing the HTTP listeners or TCP ports for this NLB"
type = any
default = [
{
"http_tcp_listener" = [
{
port = "80"
protocol = "TCP"
},
{
port = "7364"
protocol = "TCP"
}
]
},
{
"http_tcp_listener" = [
{
port = "8080"
protocol = "TCP"
},
{
port = "7365"
protocol = "TCP"
}
]
}
]
}
main.tf
module "create_network_lb" {
count = length(var."http_tcp_listeners")
source = "../../modules/lb"
subnets = tolist(data.aws_subnet_ids.private_compute[0].ids)
vpc_id = sort(data.aws_vpcs.platform_private_vpc.ids)[0]
target_groups = lookup(var.target_groups[count.index], "target_group", null)
http_tcp_listeners = lookup(var.http_tcp_listeners[count.index], "http_tcp_listener", null)
module
resource "aws_lb_listener" "frontend_http_tcp" {
count = var.create_lb ? length(var.http_tcp_listeners) : 0
load_balancer_arn = aws_lb.default[0].arn
port = var.http_tcp_listeners[count.index]["port"]
protocol = var.http_tcp_listeners[count.index]["protocol"]
dynamic "default_action" {
for_each = length(keys(var.http_tcp_listeners[count.index])) == 0 ? [] : [var.http_tcp_listeners[count.index]]
content {
type = lookup(default_action.value, "action_type", "forward")
target_group_arn = contains([null, "", "forward"], lookup(default_action.value, "action_type", "")) ? aws_lb_target_group.main[lookup(default_action.value, "target_group_index", count.index)].id : null
dynamic "redirect" {
for_each = length(keys(lookup(default_action.value, "redirect", {}))) == 0 ? [] : [lookup(default_action.value, "redirect", {})]
content {
path = lookup(redirect.value, "path", null)
host = lookup(redirect.value, "host", null)
port = lookup(redirect.value, "port", null)
protocol = lookup(redirect.value, "protocol", null)
query = lookup(redirect.value, "query", null)
status_code = redirect.value["status_code"]
}
}
dynamic "fixed_response" {
for_each = length(keys(lookup(default_action.value, "fixed_response", {}))) == 0 ? [] : [lookup(default_action.value, "fixed_response", {})]
content {
content_type = fixed_response.value["content_type"]
message_body = lookup(fixed_response.value, "message_body", null)
status_code = lookup(fixed_response.value, "status_code", null)
}
}
}
}
}
When performing a "terraform plan", it displays only the last "http_tcp_listener" value. The variable for the module must be in format "[{port=80, protocol="TCP"},{port=7364, protocol="TCP"}]" hence, everything after each iteration of "http_tcp_listener".
During troubleshooting, Terraform seems to think that the variable is a tuple with one element per the error:
Error: Invalid index
on main.tf line 86, in module "create_network_lb":
86: http_tcp_listeners = [lookup(var.http_tcp_listeners[1], "http_tcp_listener")]
|----------------
| var.http_tcp_listeners is tuple with 1 element
The given key does not identify an element in this collection value.
If I manually change one of the keys from "http_tcp_listener" to "http_tcp_listener1", and reflect this in the main.tf lookup value, it will display that value. i.e, if I rename the first key and reference it, terraform plan will display ports 80 and 7364 instead of 8080 and 7365.
Any help would be greatly appreciated.

Answer 1

Solved by re-creating the data structure, and using for_each to call the module. Details here.