How can I reference the map variable in the terraform? <Azure> - terraform

Question

main.tf wrote:
terraform {
required_providers {
azurerm = {
source = "hashicorp/azurerm"
version = ">= 2.26"
}
}
}
provider "azurerm" {
features {}
}
resource "azurerm_resource_group" "rg" {
name = "Product-RG"
location = var.location
}
resource "azurerm_virtual_network" "vnet" {
resource_group_name = azurerm_resource_group.rg.name
name = "Product-VNet"
address_space = [lookup(var.vnetAddress, var.location)]
location = var.location
subnet {
name = "Web-Sub1"
address_prefix = ["${lookup(var.subnetAddress[var.location], "web1")}"]
}
subnet {
name = "Web-Sub2"
address_prefix = [lookup(var.subnetAddress[var.location], "web2")]
}
In Web-Sub1, i originally brought address_prefix like Web-Sub2, but now i'm trying like address_prefix on Web-Sub1 after the error occurred.
An error has occurred as below.
Error: Incorrect attribute value type
on main.tf line 27, in resource "azurerm_virtual_network" "vnet":
27: address_prefix = ["${lookup(var.subnetAddress[var.location], "web1")}"]
Inappropriate value for attribute "address_prefix": string required.
Error: Incorrect attribute value type
on main.tf line 31, in resource "azurerm_virtual_network" "vnet":
31: address_prefix = [lookup(var.subnetAddress[var.location], "web2")]
Inappropriate value for attribute "address_prefix": string required.
variable.tf wrote:
variable "location" {}
variable "vnetAddress" {
type = map
default = {
westus = "192.168.1.0/27"
eastus = "192.168.11.0/27"
}
}
variable "subnetAddress" {
type = map
default = {
westus = {
web1 = "192.168.1.0/27"
web2 = "192.168.1.32/27"
was1 = "192.168.1.64/27"
was2 = "192.168.1.96/27"
db1 = "192.168.1.128/27"
db2 = "192.168.1.160/27"
}
eastus = {
web1 = "192.168.11.0/27"
web2 = "192.168.11.32/27"
was1 = "192.168.11.64/27"
was2 = "192.168.11.96/27"
db1 = "192.168.11.128/27"
db2 = "192.168.11.160/27"
}
}
}
I wonder why there is an error that needs to be written in string format and why I can't bring the data.

Answer 1

You are almost there, just that address_prefix argument needs to be a string and you are passing a list of strings address_prefix = [lookup(var.subnetAddress[var.location], "web2")]
subnet {
name = "Web-Sub1"
address_prefix = lookup(var.subnetAddress[var.location], "web1")
}
subnet {
name = "Web-Sub2"
address_prefix = lookup(var.subnetAddress[var.location], "web2")
}
This should work.
Refer azurerm_virtual_network resource, address_prefix is passed as a string rather a list of strings.