Terraform - issue with tags formating for Azure

Question

I have issue with tags, this pattern worked on AWS but for Azure i got error which is strange, can someone review and help? Thanks.

$ terraform plan

Error: azurerm_virtual_network.vnet: 1 error(s) occurred:

• azurerm_virtual_network.vnet: At column 5, line 2: merge: argument 1 should be type map, got type string in:

  ${ merge(map("Name", var.env_name), var.global_tags, var.vnet_tags)}

  main.tf

  resource "azurerm_resource_group" "vnet" {
    name     = "${var.resource_group_name}"
    location = "${var.location}"
  }
  
  resource "azurerm_virtual_network" "vnet" {
    name                = "${var.vnet_name}"
    location            = "${var.location}"
    address_space       = ["${var.address_space}"]
    resource_group_name = "${azurerm_resource_group.vnet.name}"
    dns_servers         = "${var.dns_servers}"
  
  tags = "${
      merge(map("Name", format("%s %s", var.env_name, "Vnet")), 
      var.global_tags, 
      var.vnet_tags)}"
  

  variables.tf

  variable "env_name" {
       default = "Company DTAP"
  }
  
  variable "global_tags" {
    default = "Company Ltd"
  }
  variable "vnet_tags" {
    default = "Production"
  }
  

Answer 1

I dont really know what you are trying to achieve, but merge works with maps, where as in your case global_tags and vnet_tags are strings. and the error says just that

so you cast your first input to the merge function to MAP, but dont cast the other ones. you should cast them to MAP as well.