HashiCorp Certified: Terraform Associate (004)

Terraform infers most dependencies by analyzing references between resource expressions and then orders operations through its dependency graph. This automatic management handles relationships visible in configuration without depending on file order. depends_on is reserved for additional relationships that Terraform cannot infer from expression references.

terraform init is responsible for installing and selecting provider plugins for a working directory. Adding -upgrade tells initialization to consider newer acceptable versions instead of retaining previously selected versions when the configured constraints allow an upgrade. The refresh, apply, and providers commands shown do not use -upgrade for this plugin update task.

The working directory must be initialized after a backend is configured or changed. terraform init prepares that backend, verifies access to it, and handles state initialization or migration as needed. Until initialization completes, later Terraform operations cannot use the newly configured remote backend correctly.

Initialization prepares the working directory and required dependencies. Validation then checks the configuration, and planning calculates proposed infrastructure actions. Placing review after the plan allows those actions to be examined before apply executes them, which is the sequence required for meaningful pre-change approval.

A parent configuration can retrieve only values that a child module explicitly exports. The networking module must define vnet_id as an output whose value references the relevant internal attribute. Once exported, the caller can access it through the module reference. Declaring it as an input variable would send a value into the module, which is the opposite direction.

Each child module has its own input-variable interface and scope. A parent module passes values through arguments in the child module block; those assignments are not inherited automatically merely because similarly named values exist in the parent. If an input is not explicitly passed, the child must have an applicable default or the input remains required.

HCL configurations can call the functions Terraform provides, but HCL does not provide a facility for declaring arbitrary user-defined functions. Repeated expressions can be organized with local values or modules, yet those constructs do not create new callable functions. The statement is therefore false.

Environment variables let the provider obtain credentials from the process environment at runtime instead of placing secret values in Terraform configuration or passing them through Terraform-managed input values. Because the credentials are supplied outside the configuration data being evaluated, this method avoids recording them as state data.

terraform plan calculates and presents the actions required to move from the current state to the declared configuration. terraform apply then executes those actions to provision the resources. Initialization prepares the working directory, while import adopts existing infrastructure rather than provisioning new infrastructure.

HCP Terraform and Terraform Cloud provide a web-based user interface for viewing and managing workspace activity without relying solely on local CLI interaction. They also keep workspace state remotely, giving runs a shared state location outside an individual operator's machine. These are two distinct platform capabilities.