terraformterraform-provider-azure

How to compare a variable against two strings?

how to check a variable string with two values in terraform.

I want to check a string in a variable with two string values something like the below code.

virtual_network_type = var.vnet_type == "External" || "Internal" ? var.vnet_type : null

But terraform throws below error message

Error: Invalid operand
│ 
│   on ../../modules/test/test-instance.tf line 51, in resource "azurerm_api_management" "apim_demo":
│   51:  virtual_network_type = var.vnet_type == "External" || "Internal" ? var.vnet_type : null
│ 
│ Unsuitable value for right operand: a bool is required.
╵

Can we do this in terraform?

Solution

  • A construct like var.vnet_type == "External" || "Internal" is something that few languages will accept, really.

    var.vnet_type == "External" || var.vnet_type == "Internal"

    On the other hand, is something that will give you a better result.

    Another solution for those kind of use cases, if you don't want to repeat the variable name is to construct a list of the acceptable values and evaluate if the variable is contained in the list.

    Something like:

    contains(["External", "Internal"], var.vnet_type)

    So,