DevOps Blog - Nicolas Paris

Loop in Terraform with For Each from Json File

Terraform

I'll loop a Terraform object based on values in a json file. Let's make the example simple with a list of DNS zone from Cloudflare. Terraform is a growing part of DevOps and Infrastructure as Code, well known in DevOps tech.

The following show two subjects,

Files structure looks like this:

- records.auto.tfvars.json
- declare_vars.tf
- main.tf
- zone.tf

The json file look like this in records.auto.tfvars.json

{
    "records": {
      "www": {
        "value"  : "127.0.0.1",
        "proxied": false
      },
      "api": {
        "value"  : "127.0.0.1",
        "proxied": true
      }
  }
}

A declare_vars.tf with the following.

variable "records" {
    description = "records"
    type = map
}

a main.tf with cloudflare provider and credential.

terraform {
  required_providers {
    cloudflare = {
      source = "cloudflare/cloudflare"
      version = "~> 3.0"
    }
  }
}

provider "cloudflare" {
  email = "myemail@example.com"
  api_key = "aaabbbcccdddeee123456789"
}

Here is the for each in Terraform, in zone.tf

variable "cloudflare_zone_id" {
  default = "123456789abcde"
}

resource "cloudflare_record" "records" {
  for_each =   var.records
  zone_id = var.cloudflare_zone_id
  name    = each.key
  value   = each.value.value
  type    = "A"
  ttl     = 3600
  proxied = each.value.proxied
}