.tfvars

formae can read Terraform and OpenTofu .tfvars files directly inside a forma, so existing variable files from a Terraform or OpenTofu codebase can drive a formae deployment without conversion or duplication.

Usage

terraform.readTFVars() parses an HCL-format .tfvars file and returns its variables as a Dynamic so values can be accessed with dot notation.

Import

import "@formae/ext/terraform.pkl"

Read a file

local vars = terraform.readTFVars("prod.tfvars")

The path is resolved relative to the forma file's directory. Absolute paths are also supported.

Access values

Given this prod.tfvars:

region         = "us-west-2"
instance_count = 3
enable_logging = true
tags           = { Name = "web-server", Environment = "production" }
zones          = ["us-west-2a", "us-west-2b"]

values come through as:

local vars = terraform.readTFVars("prod.tfvars")

vars.region          // "us-west-2"
vars.instance_count  // 3
vars.enable_logging  // true
vars.tags.Name       // "web-server"
vars.zones           // List("us-west-2a", "us-west-2b")

Example forma

amends "@formae/forma.pkl"
import "@formae/formae.pkl"
import "@formae/ext/terraform.pkl"
import "@aws/aws.pkl"
import "@aws/sqs/queue.pkl"

local tfvars = terraform.readTFVars("env/prod.tfvars")

forma {
  new formae.Stack {
    label = "my-stack"
    description = "Stack using tfvars"
  }

  new formae.Target {
    label = "aws-target"
    config = new aws.Config {
      region = tfvars.region
    }
  }

  new queue.Queue {
    label = "my-queue"
    queueName = "app-\(tfvars.region)-queue"
  }
}

The same prod.tfvars can stay shared between Terraform or OpenTofu and formae during a migration, eliminating the need to maintain two sets of inputs.

Supported types

tfvars type	Pkl type
"string"	String
42	Int
3.14	Float
true / false	Boolean
["a", "b"]	List
{ key = "val" }	Dynamic (dot-accessible)
null	Null
Heredoc (<<EOF)	String