Create random resource name in Terraform

There are several random resources you can use in Terraform

https://www.terraform.io/docs/providers/random/index.html

Resources

random_id
random_pet
random_shuffle
random_string

Use random_id as a sample, and the official codes in resource azurerm_storage_account

You can define the resource azurerm_storage_account name easily.

resource "random_id" "storage_account" {
  byte_length = 8
}

resource "azurerm_storage_account" "testsa" {
  name                = "tfsta${lower(random_id.storage_account.hex)}"
  resource_group_name = "${azurerm_resource_group.testrg.name}"

  location     = "westus"
  account_type = "Standard_GRS"

  tags {
    environment = "staging"
  }
}