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!
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"
}
Related
I have been trying to figure out what would be the most ideal option to deploy some fundamental, mostly identical resources (vnet, subnet, bastion host, nsg, etc.) resources in Azure, using Terraform.
I have tried it with for_each and it was working just fine until I have faced a problem where I had to pass a value to an attribute from a resource which was created with for_each. Let me show you:
So this is obviously working, nothing wrong with the following resources:
resource "azurerm_subnet" "AzureBastionSubnet" {
for_each = var.bastion_subnet
name = each.value["name"]
resource_group_name = azurerm_resource_group.rg.name
virtual_network_name = azurerm_virtual_network.vnet[each.key].name
address_prefixes = each.value["address_prefixes"]
depends_on = [azurerm_virtual_network.vnet]
}
resource "azurerm_public_ip" "bastion_public_ip" {
for_each = toset(var.public_ip_location)
name = "bastion-public-ip-${each.value}"
location = each.value
resource_group_name = azurerm_resource_group.rg.name
allocation_method = "Static"
sku = "Standard"
depends_on = [azurerm_subnet.AzureBastionSubnet]
}
But the problem starts now when in the following resource I need to pass attribute values from resources which were created with for_each. How on earth do I pass the right attributes from the created bastion subnets and public IPs to the subnet_id and public_ip_address_id?
resource "azurerm_bastion_host" "bastion" {
for_each = toset(var.location_list)
name = "bastion-${each.value}"
location = each.value
resource_group_name = azurerm_resource_group.rg.name
ip_configuration {
name = "configuration"
subnet_id = azurerm_subnet.AzureBastionSubnet.id
public_ip_address_id = azurerm_public_ip.bastion_public_ip.id
}
depends_on = [azurerm_public_ip.bastion_public_ip]
}
Thanks!
I was looking into Terraform's lookup, and also the for loop and I am sure they could make it work but I just cannot seem to figure it out.
You might be creating multiple items of azurerm_subnet.AzureBastionSubnet as you are using for_each here
resource "azurerm_subnet" "AzureBastionSubnet" {
for_each = var.bastion_subnet
name = each.value["name"]
resource_group_name = azurerm_resource_group.rg.name
virtual_network_name = azurerm_virtual_network.vnet[each.key].name
address_prefixes = each.value["address_prefixes"]
depends_on = [azurerm_virtual_network.vnet]
}
So you may want to refer to your individual azurerm_subnet instance by passing your var.bastion_subnet set member, or its map key.
for example:
resource "azurerm_bastion_host" "bastion" {
..
ip_configuration {
...
subnet_id = azurerm_subnet.AzureBastionSubnet["subnet-1"].id
}
depends_on = [azurerm_public_ip.bastion_public_ip]
}
Where subnet-1 is a key in my var.bastion_subnet map.
From Terraform documentation:
Referring to Instances
When for_each is set, Terraform distinguishes between the block
itself and the multiple resource or module instances associated with
it. Instances are identified by a map key (or set member) from the
value provided to for_each.
<TYPE>.<NAME> or module.<NAME> (for example,
azurerm_resource_group.rg) refers to the block. <TYPE>.<NAME>[<KEY>]
or module.<NAME>[<KEY>] (for example,
azurerm_resource_group.rg["a_group"],
azurerm_resource_group.rg["another_group"], etc.) refers to individual
instances.
I have a pipeline that downloads standard Terraform modules and creates resources.
"Module-ResourceGroup" deploys resource group.
"Module-Vnet" which deploys vnet.
"Module-Subnet" which deploys subnets.
My problem is when I kick the pipeline for the first time my pipeline fails reason because Module-Subnet gives me an error message that Vnet does not exist.
However, when I run the same pipeline for a second time, my Subnets get deployed without any issues as during the first run, then Vnet gets created.
I guess I have two solutions :
depends_on where I can say that by subnet module is dependent on vnet module.
Introduce a wait of 3 mins in the subnet module before it gets executed.
Q1. why it is happening? whereas as per terraform "Most of the time, Terraform infers dependencies between resources based on the configuration given" https://learn.hashicorp.com/tutorials/terraform/dependencies
if anything is wrong with the way I have written modules?
Q2. What is a better solution depends_on OR introduce wait
Q3. Is there any other way to fix it?
Below are my modules.
Module-ResourceGroup/main.tf
resource "azurerm_resource_group" "my-resourcegroup" {
name = format("%s-%s",var.resource_group_name,var.env)
location = var.location
}
Module-Vnet/main.tf
resource "azurerm_virtual_network" "my-vnet" {
name = format("%s-%s",var.vnet_name,var.env)
resource_group_name = format("%s-%s",var.resource_group_name,var.env)
location = var.location
address_space = var.address_space
}
Module-Subnet/main.tf
resource "azurerm_subnet" "my-subnet" {
for_each = var.subnetsconfig
name = format("%s-%s",each.key,var.env)
address_prefixes = each.value["address_prefixes"]
virtual_network_name = format("%s-%s",var.vnet_name,var.env)
resource_group_name = format("%s-%s",var.resource_group_name,var.env)
}
If you use the output of a resource as the input of another resource then Terraform will understand it as an implicit dependency. For example (as you did not post all of your code):
Module-ResourceGroup/main.tf
resource "azurerm_resource_group" "my-resourcegroup" {
name = format("%s-%s",var.resource_group_name,var.env)
location = var.location
}
Module-Vnet/main.tf
resource "azurerm_virtual_network" "my-vnet" {
name = format("%s-%s",var.vnet_name,var.env)
resource_group_name = azurerm_resource_group.my-resourcegroup.name
location = var.location
address_space = var.address_space
}
Module-Subnet/main.tf
resource "azurerm_subnet" "my-subnet" {
for_each = var.subnetsconfig
name = format("%s-%s",each.key,var.env)
address_prefixes = each.value["address_prefixes"]
virtual_network_name = azurerm_virtual_network.my-vnet.name
resource_group_name = azurerm_resource_group.my-resourcegroup.name
}
I keep getting this weird error according to me, is there a fix for this.
data "azurerm_resource_group" "rg" {
name = var.resource_group_name
#environment = var.environment
}
resource "azurerm_virtual_network" "vnet" {
name = var.vnet_name
location = var.location
resource_group_name = var.resource_group_name
address_space = var.address_space
}
resource "azurerm_subnet" "subnet" {
name = var.subnet_name
resource_group_name = var.resource_group_name
virtual_network_name = var.vnet_name
address_prefixes = ["10.0.0.0/24"]
service_endpoints = ["Microsoft.Sql"]
delegation {
name = "delegation"
service_delegation {
name = "Microsoft.ContainerInstance/containerGroups"
actions = ["Microsoft.Network/virtualNetworks/subnets/join/action", "Microsoft.Network/virtualNetworks/subnets/prepareNetworkPolicies/action"]
}
}
}
I keep getting this error
azurerm_subnet.subnet: Creating...
azurerm_virtual_network.vnet: Creating...
azurerm_virtual_network.vnet: Creation complete after 5s [id=/subscriptions/e4da9536-6759-4506-b0cf-10c70facd033/resourceGroups/rg-sagar/providers/Microsoft.Network/virtualNetworks/vnet]
╷
│ Error: creating Subnet: (Name "subnet" / Virtual Network Name "vnet" / Resource Group "rg-sagar"): network.SubnetsClient#CreateOrUpdate: Failure sending request: StatusCode=404 -- Original Error: Code="ResourceNotFound" Message="The Resource 'Microsoft.Network/virtualNetworks/vnet' under resource group 'rg-sagar' was not found. For more details please
go to https://aka.ms/ARMResourceNotFoundFix"│
│ with azurerm_subnet.subnet,
│ on main.tf line 14, in resource "azurerm_subnet" "subnet":
│ 14: resource "azurerm_subnet" "subnet" {
│
Even after the vnet is created, it is unable to create a vnet, any idea how I can make this work
Any idea how to fix this?
You need to use this statement virtual_network_name = azurerm_virtual_network.vnet.name instead of virtual_network_name = var.vnet_name.
Becuause virtual_network_name = var.vnet_name in subnet resource block simultaneously creating subnet and vnet so this is not good fit in azure. Because subnet dependent on Vnet. So Vnet Should create first. So you need to use virtual_network_name = azurerm_virtual_network.vnet.name for using the existing Vnet.
Terraform Code
provider "azurerm" {
features{}
}
data "azurerm_resource_group" "rg" {
name = var.resource_group_name
#environment = var.environment
}
resource "azurerm_virtual_network" "vnet" {
name = var.vnet_name
location = data.azurerm_resource_group.rg.location
resource_group_name = var.resource_group_name
address_space = var.address_space
}
resource "azurerm_subnet" "subnet"{
name = var.subnet_name
resource_group_name = var.resource_group_name
virtual_network_name = azurerm_virtual_network.vnet.name
address_prefixes = ["10.0.0.0/24"]
service_endpoints = ["Microsoft.Sql"]
delegation {
name = "delegation"
service_delegation {
name = "Microsoft.ContainerInstance/containerGroups"
actions = ["Microsoft.Network/virtualNetworks/subnets/join/action", "Microsoft.Network/virtualNetworks/subnets/prepareNetworkPolicies/action"]
}
}
}
I think this question requires a bit more explanation, since there is nothing wrong with the code. Terraform is trying to be smart about the way it creates resources, so it tries to create as much as it can in one run. This is why there is an option called -parallelism:
-parallelism=n Limit the number of parallel resource operations.
Defaults to 10.
This means that when running terraform apply, Terraform will try to run 10 resource operations including resource creation. In your case, it will try to create both the vnet and the subnet resource (parallelism applies in apply, plan and destroy). However, since you are using the same variable in both resources (var.vnet_name), Terraform is not aware that there are dependencies between the two. The way you have structured your code now would work if you were to create the vnet first and add the subnet resource after the vnet is created. Or if you are feeling adventurous you could set the parallelism to 1. Since you probably do not want that, the best way to tell Terraform in which order to create stuff is by using resource dependencies. Terraform has a concept of implicit [1] and explicit [2] dependencies. Dependencies help Terraform decide what needs to be created, based on the graph it creates [3].
There are two options in your case:
Create an implicit dependency between vnet and subnet
Create an explicit dependency between vnet and subnet
As using depends_on (or explicit dependency) is advised only in cases where there is not another way to tell Terraform that two resources are interdependent, the best way to do it is by using the implicit dependency:
data "azurerm_resource_group" "rg" {
name = var.resource_group_name
}
resource "azurerm_virtual_network" "vnet" {
name = var.vnet_name
location = var.location
resource_group_name = var.resource_group_name
address_space = var.address_space
}
resource "azurerm_subnet" "subnet" {
name = var.subnet_name
resource_group_name = var.resource_group_name
virtual_network_name = azurerm_virtual_network.vnet.name # <-- implicit dependency
address_prefixes = ["10.0.0.0/24"]
service_endpoints = ["Microsoft.Sql"]
delegation {
name = "delegation"
service_delegation {
name = "Microsoft.ContainerInstance/containerGroups"
actions = ["Microsoft.Network/virtualNetworks/subnets/join/action", "Microsoft.Network/virtualNetworks/subnets/prepareNetworkPolicies/action"]
}
}
}
The vnet resource exports some attributes after it is created [4], including the name attribute. This helps with creating the implicit dependency: by referencing a resource and one of the attributes that is available after the resource is created, you are telling Terraform that it first needs to create the vnet and only after it is available it can start with subnet creation.
[1] https://www.terraform.io/language/resources/behavior#resource-dependencies
[2] https://www.terraform.io/language/meta-arguments/depends_on
[3] https://www.terraform.io/internals/graph#resource-graph
[4] https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/virtual_network#attributes-reference
I was trying to test the scenario of handling external changes to existing resources and then syncing my HCL config to the current state in the next apply. I could achieve that using 'taint' for the modified resource, but TF deleted other resources which were deployed during the first 'apply'. Here is the module code for a VNet with 3 subnets(prod,dmz and app) and 3 NSGs associated. And I tested with modifying one of the NSGs but TF deleted all of the subnets-
VNET-
resource "azurerm_virtual_network" "BP-VNet" {
name = var.Vnetname
location = var.location
resource_group_name = var.rgname
address_space = var.vnetaddress
subnet {
name = "GatewaySubnet"
address_prefix = "10.0.10.0/27"
}
}
Subnet -
resource "azurerm_subnet" "subnets" {
count = var.subnetcount
name = "snet-prod-${lookup(var.snettype, count.index, "default")}-001"
address_prefixes = ["10.0.${count.index+1}.0/24"]
resource_group_name = var.rgname
virtual_network_name = azurerm_virtual_network.BP-VNet.name
}
NSGs-
resource "azurerm_network_security_group" "nsgs" {
count = var.subnetcount
name = "nsg-prod-${lookup(var.snettype, count.index, "default")}"
resource_group_name = var.rgname
location = var.location
--------
}
BastionSubnet-
resource "azurerm_subnet" "bastionsubnet" {
name = "AzureBastionSubnet"
virtual_network_name = azurerm_virtual_network.BP-VNet.name
resource_group_name = var.rgname
address_prefixes = [ "10.0.5.0/27" ]
}
The end result of second apply is -
With just Gateway subnet. It should not have deleted rest of the 4 subnets. Why is this happening?
The solution may confuse you. You can separate the GatewaySubnet from the azurerm_virtual_network block into an azurerm_subnet block. The code looks like this:
resource "azurerm_subnet" "gateway" {
name = "GatewaySubnet"
resource_group_name = var.rgname
virtual_network_name = azurerm_virtual_network.BP-VNet.name
address_prefixes = ["10.0.10.0/27"]
}
I don't know the certain reason, but it solves your issue.
In my main terraform file I have:
resource "azurerm_resource_group" "rg" {
name = var.rg_name
location = var.location
}
resource "azurerm_public_ip" "public_ip" {
name = "PublicIP"
location = azurerm_resource_group.rg.location
resource_group_name = azurerm_resource_group.rg.name
domain_name_label = var.domain_name_label
allocation_method = "Dynamic"
}
And in my outputs file I have:
data "azurerm_public_ip" "public_ip" {
name = "PublicIP"
resource_group_name = azurerm_resource_group.rg.name
depends_on = [azurerm_resource_group.rg, azurerm_public_ip.public_ip]
}
output "public_ip" {
value = data.azurerm_public_ip.public_ip.ip_address
}
All the resources including IP get created, however the output is blank. How can I fix this?
Make sure output.tf contains only output tags and main.tf contains resources tags
The following works just fine for me:
Main.tf
resource "azurerm_resource_group" "example" {
name = "resourceGroup1"
location = "West US"
}
resource "azurerm_public_ip" "example" {
name = "acceptanceTestPublicIp1"
resource_group_name = azurerm_resource_group.example.name
location = azurerm_resource_group.example.location
allocation_method = "Static"
tags = {
environment = "Production"
}
}
Output.tf
output "azurerm_public_ip" {
value = azurerm_public_ip.example.ip_address
}
In case you want to have a dependency between resources, use depends_on inside the resource tag.
For example:
depends_on = [azurerm_resource_group.example]
Steps to reproduce:
terraform init
terraform plan
terraform apply
terraform output
Update-
The reason you get blank public IP is since declaring allocation_method = "Dynamic"
From the docs:
Note Dynamic - Public IP Addresses aren't allocated until they're assigned to a
resource (such as a Virtual Machine or a Load Balancer) by design
within Azure.
Full working example with dynamic allocation.
I had the same issue. The actual problem seems to be the dynamic allocation. The IP address is not known until it is actually used by a VM.
In my case, I could solve the issue by adding the VM (azurerm_linux_virtual_machine.testvm) to the depends_on list in the data source:
data "azurerm_public_ip" "public_ip" {
name = "PublicIP"
resource_group_name = azurerm_resource_group.rg.name
depends_on = [ azurerm_public_ip.public_ip, azurerm_linux_virtual_machine.testvm ]
}
Unfortunately, this seems not to be documented in https://www.terraform.io/docs/providers/azurerm/d/public_ip.html