Saving Terraform State in S3

Source: Dev.to

Configuring S3 as a Terraform Backend

Terraform can store its state in an S3 bucket. Below is a minimal configuration that sets up the S3 backend:

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = ">= 4.0"
    }
  }
  required_version = ">= 1.0"

  backend "s3" {
    bucket                  = "terraform-state-dev"
    key                     = "my-key"
    region                  = "us-east-1"
    shared_credentials_file = "~/.aws/credentials"
  }
}

• You can use a single key (the key argument) to store all of your Terraform state in one file, or
• You can allocate one key per Terraform workspace (or per environment) to keep states isolated.

Migrating Existing State to S3

If you already have a local state file or are using a different backend, you can migrate it to the S3 bucket with:

terraform init -migrate-state

Warning: Losing your Terraform state can cause significant trouble, as Terraform relies on that state to track resources. Ensure the S3 bucket is versioned and backed up to prevent accidental loss.