Section Introduction Terraform Workflow

In this lesson you’ll learn the standard Terraform workflow that lets you manage infrastructure safely, consistently, and with full auditability. The workflow is intentionally simple so you can review and control every change. Core workflow steps:

Write configuration (create .tf files)
Initialize the working directory (terraform init)
Validate and format (terraform fmt, terraform validate)
Plan changes (terraform plan)
Apply changes (terraform apply)
Inspect state and outputs
Manage environments (optional workspaces)
Destroy infrastructure when needed (terraform destroy)

Each step reduces risk and makes infrastructure changes predictable. Below we walk through the workflow, show common commands, and list best practices.

Store Terraform configurations in version control, run terraform fmt and terraform validate in CI, and always review terraform plan output before applying changes.

1) Write configuration

Author Terraform configuration files using the HashiCorp Configuration Language (HCL). Organize code into logical files such as main.tf, variables.tf, outputs.tf, and providers.tf. Example minimal configuration:

# providers.tf
terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 5.0"
    }
  }
  required_version = ">= 1.5.0"
}

provider "aws" {
  region = "us-west-2"
}

# main.tf
resource "aws_s3_bucket" "example" {
  bucket = "example-terraform-bucket-12345"
  acl    = "private"
}

Best practices when writing config:

Break code into purpose-specific files for readability and reuse.
Use variables for environment-specific values and provide sensible defaults.
Pin provider versions in required_providers to avoid unexpected upgrades.
Avoid hard-coding secrets — use secret managers or environment variables.

2) Initialize the working directory

Initialization downloads providers and configures the backend. Run this once per directory (or whenever backend/provider requirements change):

terraform init

What terraform init does:

Downloads provider plugins required by your configuration.
Initializes and validates the backend (local or remote) used to store state.
Prepares the working directory for subsequent Terraform commands.

Useful flags:

-backend-config="key=value" — override backend config values at init time.
-reconfigure — ignore existing backend configuration and reconfigure.

3) Validate and format

Catch errors early and keep code consistent:

terraform fmt        # Formats HCL files to a canonical style
terraform validate   # Validates syntax and basic provider configuration

terraform validate performs static checks on your configuration. Combine these commands in pre-commit hooks or CI pipelines.

4) Plan changes

terraform plan shows a preview of the changes Terraform will make—do not skip this step. Generate a human-readable plan:

terraform plan

Create a saved plan (binary) for automation and safe applies:

terraform plan -out=plan.tfplan

Notes:

Use -out to create a plan file that can be applied later (recommended for CI/CD).
The plan uses symbols: + create, ~ update in-place, -/+ destroy and recreate, - destroy.
Inspect a saved plan with terraform show plan.tfplan.

5) Apply changes

Apply interactive changes (prompts for confirmation):

terraform apply

Apply from a saved plan (non-interactive, safe for automation):

terraform apply plan.tfplan

When you apply:

Terraform updates real resources to match your configuration.
The state file is written/updated to reflect the new resource state.
When using a remote backend, state locking prevents concurrent writes.

Always review the terraform plan output before applying. Plans indicate destructive changes (resource deletions) — verify those carefully.

6) Inspect state and outputs

Commands for examining Terraform state and outputs:

terraform show                # Show current state or a saved plan
terraform state list          # List resources tracked in state
terraform output              # Display named outputs
terraform state pull > state.json  # Export state to JSON

Avoid manual edits to the state file unless absolutely necessary and you fully understand the implications.

7) Manage environments with workspaces (optional)

Workspaces allow multiple states within the same configuration directory (e.g., dev, prod):

terraform workspace list
terraform workspace new dev
terraform workspace select prod

Workspaces are convenient for small environment splits but for larger teams or stricter separation consider separate state backends or independent Terraform configurations.

8) Destroy infrastructure

Remove resources managed by a configuration when needed:

terraform destroy

Or create and apply a destroy plan:

terraform plan -destroy -out=destroy.tfplan
terraform apply destroy.tfplan

terraform destroy shows a plan and prompts before deleting resources.

Quick reference — common Terraform commands

Command	Purpose
`terraform init`	Initialize working directory and download providers
`terraform fmt`	Format HCL files to canonical style
`terraform validate`	Validate configuration for syntax and basic issues
`terraform plan`	Preview changes without applying
`terraform plan -out=plan.tfplan`	Save a binary plan for later `apply`
`terraform apply`	Apply changes interactively
`terraform apply plan.tfplan`	Apply a previously saved plan (non-interactive)
`terraform show`	Show state or a saved plan
`terraform state list`	List resources tracked in state
`terraform output`	Print outputs defined in configuration
`terraform workspace`	Manage named workspaces
`terraform destroy`	Destroy resources managed by the configuration

Additional best practices

Store state in a remote backend (e.g., Amazon S3 + DynamoDB for locking, or Terraform Cloud/Enterprise) to enable collaboration and locking.
Pin provider versions in required_providers to prevent unexpected behavior after provider updates.
Use CI pipelines to run terraform plan and require code review before terraform apply.
Enforce terraform fmt and terraform validate in CI or pre-commit hooks.
Avoid storing sensitive secrets in .tf files. Use secure variables, secret management systems, or encrypted storage.
Use -out plans in automation to separate plan and apply phases and to guarantee the exact plan is applied.

Links and references

Terraform language docs: https://developer.hashicorp.com/terraform/language
Terraform CLI docs: https://developer.hashicorp.com/terraform/cli
Terraform Cloud: https://www.terraform.io/cloud
AWS S3: https://aws.amazon.com/s3/
AWS DynamoDB: https://aws.amazon.com/dynamodb/

This lesson provided a concise, practical workflow for using Terraform safely and predictably: write configuration, initialize, validate/plan, apply, inspect state, manage environments, and destroy when needed. For deeper dives, consult the linked Terraform documentation and provider-specific guides.

Course Introduction

Preparing Your Environment

Terraform Foundations

The Core Terraform Workflow

Terraform CLI

Terraform File Structure and Organization

Terraform Configuration - Fundamentals

Understading and Managing Terraform State

Marking Code Reusable

Refactoring Terraform State

Terraform Modules

Managing Resource Behavior and Dependencies

Securing Terraform Configurations

Terraform Troubleshooting

HCP Terraform

Section Introduction Terraform Workflow

1) Write configuration

2) Initialize the working directory

3) Validate and format

4) Plan changes

5) Apply changes

6) Inspect state and outputs

7) Manage environments with workspaces (optional)

8) Destroy infrastructure

Quick reference — common Terraform commands

Additional best practices

Links and references

Watch Video

​1) Write configuration

​2) Initialize the working directory

​3) Validate and format

​4) Plan changes

​5) Apply changes

​6) Inspect state and outputs

​7) Manage environments with workspaces (optional)

​8) Destroy infrastructure

​Quick reference — common Terraform commands

​Additional best practices

​Links and references

Watch Video

1) Write configuration

2) Initialize the working directory

3) Validate and format

4) Plan changes

5) Apply changes

6) Inspect state and outputs

7) Manage environments with workspaces (optional)

8) Destroy infrastructure

Quick reference — common Terraform commands

Additional best practices

Links and references