Issues with creating multiple vm's with Terraform for Azure - virtual-machine

Question

I am having issues with creating multiple virtual machines in Azure using Terraform. While creating the network interfaces I run into an error regarding the creation of the public ip address id:
I assume that I am using the count function incorrectly, or need a different approach entirely.
Code:
provider "azurerm" {
version = "~>2.0"
features {}
subscription_id = "XXXX"
client_id = "XXXX"
client_secret = "XXXX"
tenant_id = "XXXX"
}
resource "azurerm_resource_group" "rg" {
name = "${var.prefix}test_project"
location = var.location
tags = var.tags
}
resource "azurerm_virtual_network" "vnet" {
name = "${var.prefix}Vnet"
address_space = ["10.0.0.0/16"]
location = var.location
resource_group_name = azurerm_resource_group.rg.name
tags = var.tags
}
resource "azurerm_subnet" "subnet" {
name = "${var.prefix}Subnet"
resource_group_name = azurerm_resource_group.rg.name
virtual_network_name = azurerm_virtual_network.vnet.name
address_prefix = "10.0.1.0/24"
}
resource "azurerm_public_ip" "publicip" {
name = "${var.prefix}PublicIP${count.index}"
location = var.location
resource_group_name = azurerm_resource_group.rg.name
allocation_method = "Dynamic"
tags = var.tags
count = 2
}
resource "azurerm_network_security_group" "nsg" {
name = "${var.prefix}NetworkSecurityGroup"
location = var.location
resource_group_name = azurerm_resource_group.rg.name
tags = var.tags
security_rule {
name = "SSH"
priority = 1001
direction = "Inbound"
access = "Allow"
protocol = "Tcp"
source_port_range = "*"
destination_port_range = "22"
source_address_prefix = "*"
destination_address_prefix = "*"
}
}
resource "azurerm_network_interface" "nic" {
name = "${var.prefix}NIC${count.index}"
location = var.location
resource_group_name = azurerm_resource_group.rg.name
tags = var.tags
count = 2
ip_configuration {
name = "${var.prefix}NICConfig${count.index}"
subnet_id = azurerm_subnet.subnet.id
private_ip_address_allocation = "Dynamic"
public_ip_address_id = ["${element(azurerm_public_ip.publicip.id, count.index)}"]
}
}
resource "azurerm_network_interface_security_group_association" "example" {
count = length(azurerm_network_interface.nic)
network_interface_id = "${azurerm_network_interface.nic[count.index]}"
network_security_group_id = azurerm_network_security_group.nsg.id
}
resource "azurerm_linux_virtual_machine" "vm" {
count = 2
name = "${var.prefix}VM${count.index}"
location = var.location
resource_group_name = azurerm_resource_group.rg.name
network_interface_ids = azurerm_network_interface.nic[count.index]
size = "Standard_DS1_v2"
tags = var.tags
os_disk {
name = "${var.prefix}OsDisk${count.index}"
caching = "ReadWrite"
storage_account_type = "Premium_LRS"
}
source_image_reference {
publisher = "Canonical"
offer = "UbuntuServer"
sku = lookup(var.sku, var.location)
version = "latest"
}
computer_name = "${var.computer_name}-${count.index}"
admin_username = var.admin_username
admin_password = var.admin_password
disable_password_authentication = false
}
Can anyone help me resolve this issue??

Answer 1

I'm pretty sure all you need to do is change
public_ip_address_id = ["${element(azurerm_public_ip.publicip.id, count.index)}"]
to
public_ip_address_id = ["${azurerm_public_ip.publicip[count.index].id}"]
In general, references like azurerm_public_ip.publicip.id work for singular resources (i.e. those that don't use count). So the use of element is kind of assuming a singular resource. As soon as count is used, resources start behaving like lists and need to be treated as such.