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Terraform Associate study materials
Terraform Associate study resources

Terraform Associate: Terraform fundamentals

Terraform Associate · Work through your exam, one topic at a time.

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Terraform fundamentals

Core versus providers

The terraform binary is a single executable containing Terraform core: the HCL parser, graph builder, state manager and plan/apply engine. Everything that talks to an API lives in providers - plugins downloaded by terraform init into .terraform/providers (or a configured plugin cache directory). Providers are versioned separately from Terraform, so a configuration usually pins both:

terraform {
  required_version = ">= 1.5.0"
  required_providers {
    aws = { source = "hashicorp/aws", version = "~> 5.0" }
  }
}

Building blocks

  • Resources - objects Terraform creates, updates and destroys.
  • Data sources - read-only lookups evaluated during refresh/plan; they create nothing.
  • Variables, locals, outputs - inputs, computed intermediates, exported values.
  • Registry - registry.terraform.io hosts public providers and modules; private registries mirror the same protocol.

Traps

  • required_providers uses source = "namespace/type"; putting a bare name or a wrong namespace causes init failures or the wrong provider being installed.
  • ~> 5.1 allows 5.x but not 6.0; >= 5.0 is not a pin and can silently jump majors.
  • Questions frequently swap resource and data - if the object already exists and is only read, it is a data source.
  • Aliased providers (provider "aws" { alias = "west" }) must be passed explicitly to child modules.
  • A provider upgrade requires terraform init -upgrade; init alone keeps the lock file version.

Rule of thumb

Ask "who makes the API call?" If the answer is the Terraform binary itself rather than a provider, the statement is false.