Terraform CLI & Core Workflow Cheat Sheet

Essential Commands, Block Types & Developer Workflow — from Write to Apply.

Core Terraform Workflow

The core developer lifecycle from writing code to provisioning and tearing down infrastructure.

HCL Block Types

Block Type	Description
`resource`	Creates & manages infrastructure objects (e.g., VMs, networks).
`data`	Reads and fetches existing external data or resources.
`variable`	Parameterizes configuration with input arguments.
`output`	Exposes values after apply for users or other configurations.
`locals`	Defines computed intermediate values and expressions.
`module`	Consumes reusable packages of Terraform configurations.
`provider`	Configures target platform plugins (e.g., AWS, Azure, GCP).
`terraform`	Configures global settings, backend storage, and `required_providers`.

Essential CLI Commands

Command	Purpose
`terraform init`	Initialize working directory, download modules, and install provider plugins.
`terraform fmt`	Rewrites configuration files to canonical formatting style.
`terraform validate`	Validates configuration syntax and internal consistency.
`terraform plan`	Generates and previews the execution plan without modifying infrastructure.
`terraform apply`	Provisions or updates the infrastructure as specified in configuration.
`terraform destroy`	Destroys all infrastructure managed by this configuration.
`terraform output`	Reads and extracts output values from the state file.
`terraform console`	Launches an interactive console for evaluating expressions and state.
`terraform graph`	Outputs the visual dependency graph in Graphviz (DOT) format.
`terraform providers`	Displays a tree of providers required by the configuration.

Variable Definition Precedence

Terraform loads variables according to a strict order of precedence. Values loaded later override those loaded earlier.

Note: CLI flags (-var and -var-file) always override file-based and environment definitions. Auto-loaded files are processed in alphabetical order.

Useful CLI Flags & Environment Variables

Common CLI Flags

Flag	Description
`-auto-approve`	Skips interactive approval prompt before applying changes.
`-target=<resource>`	Focuses execution only on a specific resource address.
`-var="k=v"`	Sets an input variable value inline via the CLI.
`-var-file=<path>`	Loads variable definitions from a specified `.tfvars` file.
`-refresh-only`	Checks state against remote objects without proposing changes.
`-out=<path>`	Writes the generated plan file to disk (e.g., `plan.out`).

Environment Variables

Variable	Description	Example / Values
`TF_LOG`	Configures logging verbosity.	`TRACE`, `DEBUG`, `INFO`, `WARN`, `ERROR`
`TF_LOG_PATH`	Writes log output to a designated file.	`/path/to/tf.log`
`TF_VAR_<name>`	Supplies an input variable value via environment.	`TF_VAR_region="us-east-1"`

HCP Terraform / Terraform Cloud Block

terraform {
  cloud {
    organization = "org"

    workspaces {
      name = "my-app"
    }
  }
}

Original by Bryan Krausen (btk.me/btk)

Core Terraform Workflow​

HCL Block Types​

Essential CLI Commands​

Variable Definition Precedence​

Useful CLI Flags & Environment Variables​

Common CLI Flags​

Environment Variables​

HCP Terraform / Terraform Cloud Block​