World map

 

BM

World T1: Blueprints

HCL blocks

You will learn: how to read a block, and how one block uses another.

Checked with OpenTofu 1.13 on 1 Nov 2026

The problem

Here is a tiny blueprint. What does it ask OpenTofu to make?

resource "random_pet" "stall" {
  length = 2
}

Watch

Tap the two lines where a new block starts.

Tap the lines that match.

0 of 2 found

A blueprint is made of block: One part of a blueprint. It starts with a type and labels, like resource "local_file" "sign", then its settings in { }.. This language is called HCL.

Try it

Build the first line of a block. It makes a file, and you call it menu.

Tap the pieces in the right order.

…

Predict

The sign uses ${random_pet.stall.id}. That is a reference: Using a value from another block by its address: type, name, then the value, like random_pet.stall.id.: type, name, then the value. What is stall here?

Try it

Open main.tf. Change Welcome to into Selamat datang ke. Then type tofu apply and yes.

Blueprint (your .tf files)init done

  • local_file.signnot built yet
  • random_pet.stallnot built yet

Built (the state file)

Nothing built yet.

Blueprint: 2 resources. Built: 0.

Change a file, then run tofu plan to see what it means.

Check

Sort the parts of a block.

Drag a card into a box. Or tap the card, then tap the box.

        You did it!

        You can now read a block and follow a reference.

        Go deeper (optional)

        Lines starting with # are comments. OpenTofu reads every .tf file in the folder as one blueprint. File names are only for people. In strings, \n is a new line and ${ } puts a value inside the text.

        The settings inside a block are called argument: One setting inside a block: a name, an equals sign and a value, like length = 2.. Each provider’s docs list the arguments its resources take.