How to iterate resources in terraform? - terraform

Question

How to iterate resources for different values of a parameter
For example, in my below terraform file I have one data block and one resource. If I pass value DB_NAME=test then its working fine. But what if I have multiple values of DB_NAME and I want it to run multiple time DB_NAME=test, app. How will I iterate over data and resource block? :
data "template_file" "search-index" {
template = "${file("search-index/search-index.sh")}"
vars {
DB_NAME = "${var.DB_NAME}"
}
}
resource "null_resource" "script" {
triggers = {
DB_NAME = "${var.DB_NAME}"
script_sha = "${sha256(file("search-index/search-index.sh"))}"
}
provisioner "local-exec" {
command = "${data.template_file.search-index.rendered}"
interpreter = ["/bin/bash", "-c"]
}
}

Answer 1

I'm not sure if I fully understood what you are trying to achieve but you can create multiple DB by defining a variables.tf like this:
variable "DB_NAME" {
description = "A list of databases"
type = list(string)
default = ["db1", "db2", "db3"]
}
And then using the for_each functionality in your terraform file:
data "template_file" "search-index" {
for_each = toset(var.DB_NAME)
template = "${file("search-index/search-index.sh")}"
vars = {
DB_NAME = each.value
}
}
resource "null_resource" "script" {
for_each = toset(var.DB_NAME)
triggers = {
DB_NAME = each.value
script_sha = "${sha256(file("search-index/search-index.sh"))}"
}
provisioner "local-exec" {
command = "${data.template_file.search-index[each.value]}"
interpreter = ["/bin/bash", "-c"]
}
}