Toggle Azure VM creation in Terraform - azure-virtual-machine

Question

I have to provision a Windows VM in Azure using terraform, only the condition is, VM(along with dependent resources, like VNET, NSG, PublicIP, etc) should be created for all other environments except DEV.
If I run terraform plan with below terraform code. I am getting this error.
##[error]Terraform command 'plan' failed with exit code '1'.: Missing resource instance key | Missing resource instance key | Missing resource instance key
[0m on main_infra_app.tf line 284, in resource "azurerm_network_interface" "network-interface":
284: subnet_id = "${[4mazurerm_subnet.snet[0m.id}"
[0m
Because azurerm_subnet.snet has "count" set, its attributes must be accessed
on specific instances.
For example, to correlate with indices of a referring resource, use:
azurerm_subnet.snet[count.index]
Terraform code:
resource "azurerm_virtual_network" "vnet-main" {
count = "${var.env == "dev" ? 0 : 1}"
name = "$var.name"
address_space = ["10.0.0.0/16"]
location = "$var.location"
resource_group_name = "${azurerm_resource_group.rg.name}"
}
#Create Public IPs
resource "azurerm_public_ip" "PublicIP" {
count = "${var.env == "dev" ? 0 : 1}"
name = "${var.ip}"
location = "${azurerm_resource_group.rg.location}"
resource_group_name = "${azurerm_resource_group.rg.name}"
allocation_method = "Static"
}
#Create Subnet
resource "azurerm_subnet" "snet" {
count = "${var.env == "dev" ? 0 : 1}"
name = "${var.subnet}"
resource_group_name = "${azurerm_resource_group.rg.name}"
virtual_network_name = "azurerm_virtual_network.vnet-main"
address_prefix = "10.0.2.0/24"
}
#Create Network Security Group
resource "azurerm_network_security_group" "NSG" {
count = "${var.env == "dev" ? 0 : 1}"
name = "${var.nsg}"
location = "${azurerm_resource_group.rg.location}"
resource_group_name = "${azurerm_resource_group.rg.name}"
security_rule {
...
}
security_rule {
...
}
}
#Create Network Interface
resource "azurerm_network_interface" "network-interface" {
count = "${var.env == "dev" ? 0 : 1}"
name = "${var.nic}"
location = "${azurerm_resource_group.rg.location}"
resource_group_name = "${azurerm_resource_group.rg.name}"
network_security_group_id = "${var.devops_stage == "dev" ? azurerm_network_security_group.NSG[count.index] : azurerm_network_security_group.NSG.id}"
ip_configuration {
name = "IP-Conf-1"
subnet_id = "${var.devops_stage == "dev" ? azurerm_subnet.snet[count.index] : azurerm_subnet.snet.id}"
private_ip_address_allocation = "Dynamic"
public_ip_address_id = "${var.devops_stage == "dev" ? azurerm_public_ip.PublicIP[count.index] : azurerm_public_ip.PublicIP.id}"
}
}
resource "azurerm_virtual_machine" "vm" {
count = "${var.env == "dev" ? 0 : 1}"
name = var.vm_name
location = "${azurerm_resource_group.rg.location}"
resource_group_name = "${azurerm_resource_group.rg.name}"
network_interface_ids = "${var.env == "dev" ? azurerm_network_interface.network-interface[count.index] : azurerm_network_interface.network-interface[count.index]}"
vm_size = "Standard_D13_v2"
..
..
..
}
Please guide me on this.

Answer 1

As I see from your Terraform code, you want to add the condition that if the variable env is matched with "dev" to judge create the VM and other resources or not. I think you only need to add the condition at the count, not any other places. So finally, the Terraform code should be like this:
resource "azurerm_virtual_network" "vnet-main" {
count = "${var.env == "dev" ? 0 : 1}"
name = "${var.name}"
address_space = ["10.0.0.0/16"]
location = "${azurerm_resource_group.rg.location}"
resource_group_name = "${azurerm_resource_group.rg.name}"
}
#Create Public IPs
resource "azurerm_public_ip" "PublicIP" {
count = "${var.env == "dev" ? 0 : 1}"
name = "${var.ip}"
location = "${azurerm_resource_group.rg.location}"
resource_group_name = "${azurerm_resource_group.rg.name}"
allocation_method = "Static"
}
#Create Subnet
resource "azurerm_subnet" "snet" {
count = "${var.env == "dev" ? 0 : 1}"
name = "${var.subnet}"
resource_group_name = "${azurerm_resource_group.rg.name}"
virtual_network_name = "${azurerm_virtual_network.vnet-main[count.index].name}"
address_prefix = "10.0.2.0/24"
}
#Create Network Security Group
resource "azurerm_network_security_group" "NSG" {
count = "${var.env == "dev" ? 0 : 1}"
name = "${var.nsg}"
location = "${azurerm_resource_group.rg.location}"
resource_group_name = "${azurerm_resource_group.rg.name}"
security_rule {
...
}
security_rule {
...
}
}
#Create Network Interface
resource "azurerm_network_interface" "network-interface" {
count = "${var.env == "dev" ? 0 : 1}"
name = "${var.nic}"
location = "${azurerm_resource_group.rg.location}"
resource_group_name = "${azurerm_resource_group.rg.name}"
network_security_group_id = "${azurerm_network_security_group.NSG[count.index].id}"
ip_configuration {
name = "IP-Conf-1"
subnet_id = "${azurerm_subnet.snet[count.index].id}"
private_ip_address_allocation = "Dynamic"
public_ip_address_id = "${azurerm_public_ip.PublicIP[count.index].id}"
}
}
resource "azurerm_virtual_machine" "vm" {
count = "${var.env == "dev" ? 0 : 1}"
name = var.vm_name
location = "${azurerm_resource_group.rg.location}"
resource_group_name = "${azurerm_resource_group.rg.name}"
network_interface_ids = "${azurerm_network_interface.network-interface[count.index].id}"
vm_size = "Standard_D13_v2"
..
..
..
}