Referencing outputs from a for_each module - terraform

Question

I have a module which has a variable defined using for_each, and its output is as below:
output "nic_ids" {
value = [for x in azurerm_network_interface.nic : x.id]
}
nic_ids = [
"/subscriptions/*****/resourceGroups/test-rg/providers/Microsoft.Network/networkInterfaces/test-nic-1",
"/subscriptions/*****/resourceGroups/test-rg/providers/Microsoft.Network/networkInterfaces/test-nic-2",
]
My aim is to pass above NIC ids to the VM module and have 1:1 mapping between NIC id and VM (test-nic-1 should only be attached to vm-1, test-nic-2 to vm-2 etc.)
module "vm" {
source = "*****/vm/azurerm"
version = "0.1.0"
vms = var.vms
nic_ids = module.nic[each.value.id].nic_ids
}
I am getting below error:
Error: each.value cannot be used in this context
on main.tf line 58, in module "vm":
58: nic_ids = module.nic[each.value.id].nic_ids
A reference to "each.value" has been used in a context in which it
unavailable, such as when the configuration no longer contains the value in
its "for_each" expression. Remove this reference to each.value in your
configuration to work around this error.
I used this similar question as reference.
Can you please suggest?

Answer 1

You could pass the above NIC id list to the VM modules with the count.
module "vm" {
source = "./modules/vms"
vm_names = ["aaa","bbb"]
nic_ids = module.nic.network_interface_nics
}
module "nic" {
source = "./modules/nic"
nic_names = ["nic1","nic2"]
}
the main.tf in the VM module:
resource "azurerm_virtual_machine" "vm-windows" {
count = length(var.vm_names)
name = var.vm_names[count.index]
resource_group_name = data.azurerm_resource_group.vm.name
location = var.location
vm_size = var.vm_size
network_interface_ids = [ var.nic_ids[count.index] ]
...
}
The output.tf in the NIC module:
output "network_interface_nics" {
description = "ids of the vm nics provisoned."
value = [for x in azurerm_network_interface.nic : x.id]
}