Generation of a set to be used in for_each

Question

Is there a way to generate a set from an Integer? It would convenient if we have a number_of_instances parameter that is converted to set to be used in for_each Meta-Argument. In result, we don't need to write:

for_each = toset(["one", "two", "three",])

In stead, we just set a parameter:

number_of_instances = 3

For now I came up with this:

variable "number_of_instances" {
  type = number
  default = 0
}

locals {
  i = [
    "a",
    "b",
    "c",
    "d",
    "e",
    "f",
    "g",
    "h",
    "i",
    "j",
  ]
}

resource "null_resource" "main" {
  for_each = toset(slice(local.i, 0, var.number_of_instances))
  connection {
    name = each.key
  }
}

Answer 1

May you could the following:

variable "number_of_instances" {
  default = 3
}

locals {
  numbers = ["one", "two", "three", "four", "five", "six"]
  number_set = slice(local.numbers, 0, var.number_of_instances)
}

and then use:

for_each = toset(local.number_set)

Off course numbers must be pre-populated first.