Terraform/HCL in Azure issues - azure

Question

I am new to HCL and Terraform and have having issues with associating a security group and a backend address pool to the network interface. I am creating 2 network interfaces in a single network interface block:
#Create network interface for 2 VMs
resource "azurerm_network_interface" "FrontNetworkInterface" {
count = 2
name = "niFront${count.index}"
location = azurerm_resource_group.PWSDevResourceGroup.location
resource_group_name = azurerm_resource_group.PWSDevResourceGroup.name
ip_configuration {
name = "ipconfFrontVM"
subnet_id = azurerm_subnet.PWSDevSubnet.id
private_ip_address_allocation = "dynamic"
}
}
I have tried associating in various ways that have produced different errors:
ATTEMPT 1:
#Connect security group to the network interface
resource "azurerm_network_interface_security_group_association" "PWSDevSecurityGroupAssoc" {
network_interface_id = azurerm_network_interface.FrontNetworkInterface.id
network_security_group_id = azurerm_network_security_group.PWSDevSecurityGroup.id
}
#Connect 2 backend ips to the load balancer
resource "azurerm_network_interface_backend_address_pool_association" "BackendIPAssoc" {
network_interface_id = azurerm_network_interface.FrontNetworkInterface.id
ip_configuration_name = "bipa"
backend_address_pool_id = azurerm_lb_backend_address_pool.BackendIpPool.id
}
ERRORS:
Error: Missing resource instance key
on front.tf line 85, in resource "azurerm_network_interface_security_group_association" "PWSDevSecurityGroupAssoc":
85: network_interface_id = azurerm_network_interface.FrontNetworkInterface.id
Because azurerm_network_interface.FrontNetworkInterface has "count" set, its
attributes must be accessed on specific instances.
For example, to correlate with indices of a referring resource, use:
azurerm_network_interface.FrontNetworkInterface[count.index]
Error: Missing resource instance key
on front.tf line 91, in resource "azurerm_network_interface_backend_address_pool_association" "BackendIPAssoc":
91: network_interface_id = azurerm_network_interface.FrontNetworkInterface.id
Because azurerm_network_interface.FrontNetworkInterface has "count" set, its
attributes must be accessed on specific instances.
For example, to correlate with indices of a referring resource, use:
azurerm_network_interface.FrontNetworkInterface[count.index]
ATTEMPT 2/3/4 (Using "[count.index]", "[count.index].id", or "[element(azurerm_network_interface.FrontNetworkInterface.*.id, count.index)]" as described in the previous error):
#Connect security group to the network interface
resource "azurerm_network_interface_security_group_association" "PWSDevSecurityGroupAssoc" {
network_interface_id = azurerm_network_interface.FrontNetworkInterface[count.index]
network_security_group_id = azurerm_network_security_group.PWSDevSecurityGroup.id
}
#Connect 2 backend ips to the load balancer
resource "azurerm_network_interface_backend_address_pool_association" "BackendIPAssoc" {
network_interface_id = azurerm_network_interface.FrontNetworkInterface[count.index]
ip_configuration_name = "bipa"
backend_address_pool_id = azurerm_lb_backend_address_pool.BackendIpPool.id
}
ERROR (Same result for [count.index].id and [element(azurerm_network_interface.FrontNetworkInterface.*.id, count.index)]):
Error: Reference to "count" in non-counted context
on front.tf line 85, in resource "azurerm_network_interface_security_group_association" "PWSDevSecurityGroupAssoc":
85: network_interface_id = azurerm_network_interface.FrontNetworkInterface[count.index]
The "count" object can only be used in "module", "resource", and "data"
blocks, and only when the "count" argument is set.
Error: Reference to "count" in non-counted context
front.tf line 91, in resource "azurerm_network_interface_backend_address_pool_association" "BackendIPAssoc":
network_interface_id = azurerm_network_interface.FrontNetworkInterface[count.index]
The "count" object can only be used in "module", "resource", and "data"
blocks, and only when the "count" argument is set.
Also, I am receiving this error on my azurerm_virtual_machine block:
line 162, in resource "azurerm_virtual_machine" "FrontEndVirtualMachines":
162: admin_ssh_key {
Blocks of type "admin_ssh_key" are not expected here.
I am following what is shown here:
https://learn.microsoft.com/en-us/azure/developer/terraform/create-linux-virtual-machine-with-infrastructure
As you can see, the admin_ssh_key block is provided. I tried using version 2.0 as used in the scripts; however, I experienced the same result.
Thanks for your help!! :)

Answer 1

When referencing a resource created with count you still need to add the .id. See the following example. For more information see this link.
provider "azurerm" {
version = "~>2.23.0"
features {}
}
resource "azurerm_resource_group" "example" {
name = "example-resources"
location = "East US"
}
resource "azurerm_virtual_network" "example" {
name = "vnet"
location = azurerm_resource_group.example.location
resource_group_name = azurerm_resource_group.example.name
address_space = ["10.0.0.0/16"]
dns_servers = ["10.0.0.4", "10.0.0.5"]
}
resource "azurerm_subnet" "example" {
name = "example"
resource_group_name = azurerm_resource_group.example.name
virtual_network_name = azurerm_virtual_network.example.name
address_prefixes = ["10.0.1.0/24"]
}
resource "azurerm_network_interface" "example" {
count = 2
name = format("int%s", count.index)
location = azurerm_resource_group.example.location
resource_group_name = azurerm_resource_group.example.name
ip_configuration {
name = "ip"
subnet_id = azurerm_subnet.example.id
private_ip_address_allocation = "dynamic"
}
}
resource "azurerm_network_security_group" "example" {
name = "acceptanceTestSecurityGroup1"
location = azurerm_resource_group.example.location
resource_group_name = azurerm_resource_group.example.name
security_rule {
name = "test123"
priority = 100
direction = "Inbound"
access = "Allow"
protocol = "Tcp"
source_port_range = "*"
destination_port_range = "*"
source_address_prefix = "*"
destination_address_prefix = "*"
}
}
resource "azurerm_network_interface_security_group_association" "secgroup" {
count = length(azurerm_network_interface.example)
network_interface_id = azurerm_network_interface.example[count.index].id
network_security_group_id = azurerm_network_security_group.example.id
}

Answer 2

I will admit that I haven't read the whole story, but it looks like your attempt #2/3/4 was pretty close. Where you use [count.index], you need to specify a count, otherwise there's no count to index. So if you just add count = 2 to those two resource blocks, it should work.
Better yet, either have the 2 as a variable, or use
count = len(azurerm_network_interface.FrontNetworkInterface)
to ensure you don't end up with mismatched numbers when you change the 2 later on.