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State File Basics

Source: doonops-curriculum/variables-state--state-basics.md

Doonops lesson

Understand state file — Terraform's memory of what it created.

State = notebook where Terraform writes "I created server i-abc123". Without it, Terraform forgets and tries duplicate.

terraform.tfstate JSON maps address to real IDs; state mv/rm; remote backend S3; locking DynamoDB.

Sticker on each box in warehouse — Terraform scans stickers next time instead of buying new boxes.

Deep explanation

Layman words first, then technical detail — read slowly

Cloud has real IDs (i-0abc...). Your .tf files only have logical names (aws_instance.app). State connects them.

main.tf says: aws_instance.app
state says:  aws_instance.app = i-0abc123 in ap-south-1
AWS has:       real running server i-0abc123

terraform state list
terraform show
terraform state show aws_instance.app

Modern HCL — names are examples, not from any third-party course

Example HCL

# terraform state list
# terraform show

Terraform runs on your computer — copy this HCL into a folder, then follow the local lab steps below.

Full implementation folder — copy all files, then run terraform commands

Copy every file below into one folder — same as a real repo module. Then run the local lab steps.

Suggested folder: Suggested path: ~/doonops-terraform/07-state/

versions.tfSee file purpose in the code below

terraform {
  required_version = ">= 1.9.0"
}

2–3 quick questions before the next module

Quick check — did this module stick?

1. Where should terraform.tfstate live in a team?

2. Outputs are used to…