How to refer to imported terraform resources

Question

I need your help. We have created a resource group (rg_networking) and virtual network(vnet_preprod) and 5 subnets in that (subnet_ad), subnet_app, subnet_ctl etc.

My import of resources works perfectly fine, however, what I don't know is to use/reference the imported resources?

terraform import --var-file=aos-1.tfvars azurerm_virtual_network.vnet_preprod /subscriptions/00000000000000000/resourceGroups/rg_networking/providers/Microsoft.Network/virtualNetworks/vnet_preprod
azurerm_virtual_network.vnet_preprod: Importing from ID "/subscriptions/00000000000000000/resourceGroups/rg_networking/providers/Microsoft.Network/virtualNetworks/vnet_preprod"...
azurerm_virtual_network.vnet_preprod: Import complete!
  Imported azurerm_virtual_network (ID: /subscriptions/00000000000000000/resourceGroups/rg_networking/providers/Microsoft.Network/virtualNetworks/vnet_preprod)
azurerm_virtual_network.vnet_preprod: Refreshing state... (ID: /subscriptions/00000000000000000-...rk/virtualNetworks/vnet_preprod)

Import successful!

The resources that were imported are shown above. These resources are now in your Terraform state and will henceforth be managed by Terraform.

In my windows-build-tf file

resource "azurerm_virtual_network" "vnet_preprod" {
  name                = ""
  address_space       = ""
  location            = ""
  resource_group_name = ""
}

I had to insert the above snippet else import would not have worked.

My previous working configuration, with Terraform creating everything and not using any imported resources is below:

variables.tfvars

address_space = [ "10.97.0.0/16" ]
virtual_network_subnet_ad = "10.97.1.0/24"
virtual_network_subnet_ad_name="groups-preprod_subnet_ad"
virtual_network_nic_ad="groups-preprod_nic_ad"

build-windows.tf

resource "azurerm_virtual_network" "tf-virtual-network" {
  name                = "${var.virtual_network_name}"
  address_space       = "${var.address_space}"
  location            = "${var.Location}"
  resource_group_name = "${var.Resource_group_name}"
}

resource "azurerm_subnet" "tf-virtual-network-subnet-ad" {
  name                 = "${var.virtual_network_subnet_ad_name}"
  resource_group_name  = "${var.Resource_group_name}"
  virtual_network_name = "${azurerm_virtual_network.tf-virtual-network.name}"
  address_prefix       = "${var.virtual_network_subnet_ad}"
}

resource "azurerm_network_interface" "tf-virtual-network-nic-ad" {
  name                = "${var.virtual_network_nic_ad}"
  location            = "${var.Location}"
  resource_group_name = "${var.Resource_group_name}"

  ip_configuration {
    name                          = "testconfiguration1"
    subnet_id                     = "${azurerm_subnet.tf-virtual-network-subnet-ad.id}"
    private_ip_address_allocation = "dynamic"
  }
}
resource "azurerm_virtual_machine" "tf-virtual-machine-name" {
  name                  = "${var.virtual_machine_name}"
  location              = "${var.Location}"
  resource_group_name   = "${var.Resource_group_name}"
  network_interface_ids = ["${azurerm_network_interface.tf-virtual-network-nic-ad.id}"]
  vm_size               = "Standard_DS3_v2"
}

My question is how to reference the imported resource, I prefer them to be parametric but if its not possible then hard coded values would be the way to move forward? do I need to create my VM in same resource group?

I can see them imported in state file, kindly guide as I'm very much new to Azure and Terraform.

Many Thanks!

Tim Tharratt Tim Tharratt · Accepted Answer · 2018-10-18T08:57:14

You can import and use resources as follows, sounds like you got this imported okay

Import your resource, use the provider / resource name e.g ‘azurerm_virtual_network.web_server_vnet’. Then in terraform re-define this using the same name and the settings it’s currently using in Azure. You can then use this like a resource that you created. May be you could define this as a data resource instead? You don’t need to add all the attributes and it won’t get destroyed if you do terraform destroy.

Import

https://resources.azure.com/ - handy for getting resource ID

terraform import azurerm_virtual_network.web_server_vnet /subscriptions/xxxxxxxxxx-xxxx-xxxx-xxx-xxxxxxxxxx/resourceGroups/tf-web-rg/providers/Microsoft.Network/virtualNetworks/web-server-vnet

In Terraform

resource "azurerm_virtual_network" "web_server_vnet" {
  name                = "vnet"
  location            = "location"
  resource_group_name = "resourceGroup"
  address_space       = ["1.1.1.0/24"]
}

data "azurerm_resource_group" "web_server_rg" {
  name = "existing RG Name"
}

How to refer to imported terraform resources

1 Answers