Using Conditions on Terraform to deploy resources on Azure

I'm currently developing new terraform modules and facing some problems validating existing resources such as resource groups.

Using the ARM template makes it possible to use the option deploy if it does not exist. But I couldn't find a similar solution on Terraform code.

For example, before creating a brand-new resource group. I would like to check if the subscription contains it and if not, create it.

    resource "azurerm_resource_group" "mssql_server_resource_group" {
  name     = var.mssql_resource_group_name
  location = "eastus"

  # Check if resource group exists before creating
  lifecycle {
    ignore_changes        = [tags] # Ignore tag changes to prevent unnecessary updates
    create_before_destroy = true   # Create a new resource before destroying the existing one
  }
}

I found the above example, but it does not work.

To check whether the resource group already exists, You can try the below code which worked for me.

I tried with the count operator to check the condition as follows:

provider "azurerm"{
features{}
}
variable "resource_group"{
type = string
}
data "azurerm_resource_group" "example" {
  name = var.resource_group
}
resource "azurerm_resource_group" "example" {
  count = length(data.azurerm_resource_group.example) == 0 ? 1 : 0
  name     = var.resource_group
  location = "eastus"
}

terraform init:

After I run the Terraform plan, it prompts me for the resource group variable. I used the existing one, and the output is as follows.

To verify again, I ran terraform plan with the new resource group name, and it returned the status "resource not found". You can then check the status and proceed accordingly.

Alternatively, you can use the below command to view the Terraform state file, including the resource ID. If the resource exists, it retrieves the following resource information.

terraform state show azurerm_resource_group.example