Terraform Associate flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Infrastructure as Code

Practice of defining and provisioning infrastructure through machine-readable files kept in version control, making deployments repeatable, reviewable, and automated instead of manual console work.

Declarative configuration model

Approach where configuration describes the desired end state and the tool determines which API calls to make, in contrast to imperative scripts that list each step.

Idempotency

Property whereby applying the same configuration repeatedly against unchanged infrastructure produces no changes, because Terraform compares desired state with recorded state before acting.

Configuration drift

Divergence between real infrastructure and recorded state or configuration, usually caused by manual changes, detected during refresh and corrected by the next apply.

HCL block syntax

Terraform language structure of a block type followed by optional quoted labels and a brace body holding key = value arguments and nested blocks.

Provider

Plugin that translates Terraform configuration into API calls for a platform such as AWS or Azure, configured in a provider block and pinned in required_providers.

Data source

Read-only lookup of an object Terraform does not manage, declared in a data block and referenced as data.type.name.attribute elsewhere in configuration.

Pessimistic version constraint

The ~> operator permits only the rightmost version component to increase, so ~> 5.1 allows 5.2 through 5.9 but rejects 6.0.

terraform init

First workflow command; downloads required providers and modules, creates the .terraform directory, writes the dependency lock file, and initializes the configured backend.

terraform validate

Checks configuration syntax, argument names, and internal references for consistency without contacting provider APIs or reading remote state.

terraform plan

Previews proposed changes by refreshing state and comparing configuration with real infrastructure; the -out flag saves the result for exact later application.

Saved plan file

Artifact produced by terraform plan -out=FILE; applying it with terraform apply FILE performs exactly the previewed actions without planning again.

count meta-argument

Creates a fixed number of resource instances addressed by numeric index such as aws_instance.web[0], with count.index available inside the block.

for_each meta-argument

Creates one instance per element of a map or set of strings, addressed by string key, which gives stable identity when collection order changes.

lifecycle block

Resource meta-argument adjusting behavior through create_before_destroy, prevent_destroy, ignore_changes, and replace_triggered_by settings.

Sensitive variable

Input declared with sensitive = true, which redacts its value from CLI plan and apply output while still storing the value in state.

Root module

The directory where terraform commands are run; its .tf files form the top-level configuration that calls child modules and configures providers.

Module source argument

Value specifying where a child module lives: a local path, a registry address of namespace/name/provider, a Git or HTTP URL, or an object storage bucket.

Module output reference

Expression module.MODULE_NAME.OUTPUT_NAME that reads an output declared inside a child module and exposes it to the calling configuration.

terraform get

Command that downloads modules referenced by configuration into .terraform/modules; terraform init performs this automatically and -upgrade fetches newer allowed versions.

Terraform state

Data mapping resource addresses in configuration to real remote object identifiers, plus cached attributes, required so Terraform knows what it manages.

State locking

Mechanism preventing concurrent runs from writing the same state simultaneously; native in HCP Terraform and implemented with DynamoDB for the S3 backend.

terraform state mv

Command that moves a resource from one address to another within state, preserving the real infrastructure instead of destroying and recreating it.

terraform import

Command that adopts an existing real object into state at a given resource address; it does not generate matching configuration for that resource.

terraform taint

Legacy command marking an object as degraded so the next apply destroys and recreates it; the plan -replace=ADDRESS option supersedes it.

moved block

Configuration block recording that a resource was renamed or relocated between modules, preventing Terraform from destroying and recreating it during refactoring.

terraform providers lock

Command that records checksums for provider packages of specified platforms in the dependency lock file, supporting offline and cross-platform installs.

TF_LOG variable

Environment variable setting Terraform logging verbosity to TRACE, DEBUG, INFO, WARN, or ERROR and sending detailed core and provider messages to stderr.

HCP Terraform workspace

Isolated environment holding state, variables, and run history for one configuration, driven either by the CLI, a VCS repository, or the API.

cloud block

Configuration block naming organization and workspaces so the local CLI executes runs remotely in HCP Terraform rather than using local state.

Variable set

Reusable collection of Terraform or environment variables in HCP Terraform that can be applied across many workspaces at once.

Sentinel policy

Policy-as-code in HCP Terraform evaluated between plan and apply; a failing policy blocks the run unless an authorized user overrides it.