Terraform script to list out ability to dynamic variable names for use in terraform

Question

I would like to define and declare same resources of different resource groups in terraform.

The end goal is to get all the resources created which are part of the specific resource group which I select from the command line when I run terraform plan. Below is the terraform script I tried to run but not sure whether the below definition an declaration is correct.Please suggest me how to write or format this script. I am new to terraform ad explore many blogs to create the below script but need clarification.

Here is the below 2 resource groups with resource variable names. var.tf:

variable "properties" {

 type = object( {
    resourcegroup_name = string
    location = string
    keyvault_name = string
    Networksecuritygroup_name = string
    Storageaccount_name = string
    Storageaccount_dev = string
    APImanagement_name = string
    APP-serviceplan_name = string
    webappservice_name = string
    SQLDatabase_name = string
    NetworkInterface_name = string
    VirtualMachine_name = string
    EndPoint = string
    CDNProfile = string
    ApplicationInsigt_name = string
    TrafficManagerProfile_name = string
    SQLServer_name = string
    Subnet_name = string
    
})
variable "resourcegroup1" {
 default = [{
   
    resourcegroup_name = "001-rg"
    location = "UK South"
    keyvault_name = "kv-001"
    TrafficManagerProfile_name = "tmp-001"
    Storageaccount_name = "stg001"
    APImanagement_name = "apm-001"
    APPserviceplan_name = "asp-001"
    webappservice_name = "was-001"
    Storageaccount_dev = "devstg001"
    SQLDatabase_name = "DB-001"
    NetworkInterface_name = "NIC-01"
    VirtualMachine_name = "VM001"
    EndPoint1 = "stg001 (stg001/stg001)"
    CDNProfile1 = "cdn_001"
    EndPoint2 = "devstg001 (devstg001/devstg001)"
    CDNProfile2 = "cdn_dev001"
    ApplicationInsigt_name = "AI-001"
    SQLServer_name = "Db-server-001"
    Subnet_name = "subnet001"
    }]
},
variable "resourcegroup2" {
 default = [{
   
    resourcegroup_name = "002-rg"
    location = "UK South"
    keyvault_name = "kv-002"
    TrafficManagerProfile_name = "tmp-002"
    Storageaccount_name = "stg002"
    APImanagement_name = "apm-002"
    APPserviceplan_name = "asp-002"
    webappservice_name = "was-002"
    Storageaccount_dev = "devstg002"
    SQLDatabase_name = "DB-002"
    NetworkInterface_name = "NIC-02"
    VirtualMachine_name = "VM002"
    EndPoint1 = "stg002 (stg002/stg002)"
    CDNProfile1 = "cdn_002"
    EndPoint2 = "devstg002 (devstg002/devstg002)"
    CDNProfile2 = "cdn_dev002"
    ApplicationInsigt_name = "AI-002"
    SQLServer_name = "Db-server-002"
    Subnet_name = "subnet002"
    }]
}

main.tf:

    terraform {
  required_providers {
    azurerm = {
      source = "hashicorp/azurerm"
      version = "2.90.0"
    }
  }
}

provider "azurerm" {
  # Configuration options
  features{}
}
data "azurerm_client_config" "current" {}

resource "azurerm_key_vault" "keyvault" {
  name                        = "${var.keyvault_name}"
  location                    = "${var.location}"
  resource_group_name         = "${var.resourcegroup_name}"
  enabled_for_disk_encryption = true
  tenant_id                   = "${data.azurerm_client_config.current.tenant_id}"
 
  sku_name = "standard"

  access_policy {
    tenant_id = "987654"
    object_id = "123456"

    key_permissions = [
      "Get",
    ]

    secret_permissions = [
      "Get",
    ]

    storage_permissions = [
      "Get",
    ]
  }
}
#---------------------------------------API Management Serrvice---------------------------------------
variable "apimAdminEmail"{
default= "abc@gmail.com"
}
variable "apimTier"{
default= "Developer_1"
}
variable "apimCapacity"{
default= "1"
}
variable "hostName"{
default= "api3"
}
resource "azurerm_api_management" "APIM" {
  name                = "${var.APImanagement_name}"
  location            = "${var.location}"
  resource_group_name = "${var.resourcegroup_name}"
  publisher_name      = "API"
  publisher_email     = "${var.apimAdminEmail}"
  

   
    sku_name     = "${var.apimTier}"
    #capacity = "${var.apimCapacity}"
  

  identity {
    type = "SystemAssigned"
  }

  
}

Answer 1

I am not quite sure about your question but I am assuming that you want two deploy two different environments using a single main.tf ( common template for two different environments) example: Dev and Stage environment.

If that is your case, Configure two separate variable.tf files for each environment and pass the variable.tf file to when initializing the terraform.

Please check the below Example

1. Create Two varaible file with diffrent name (dev.tfvars and stage.tfvars)

dev.tfvars

resourcegroup_name = "002-rg"
location = "UK South"
keyvault_name = "kv-002"
TrafficManagerProfile_name = "tmp-002"

stage.tfvars

resourcegroup_name = "001-rg"
location = "UK South"
keyvault_name = "kv-001"
TrafficManagerProfile_name = "tmp-001"

2. Declare defaults for each variable

variables.tf

variable "resourcegroup_name" {
    default = ""
}
variable "location" {
    default = ""
}
....

4. when running the terraform automation, pass the var fie which you have created

terraform init
terraform plan -var-file="dev.tfvars"
terraform apply -var-file="dev.tfvars"