Chicken or the Egg. Terraform’s Remote Backend

interpolation.tf

# this won't work

terraform {
  backend "s3" {
    bucket = "${var.bucket}"
    dynamodb_table = "${var.dynamodb_table}"
    # reminder of the config...
  }
}

main.tf

# setup/main.tf

provider "aws" {
  profile = "${var.profile}"
  region = "${var.region}"
}

module "backend" {
  source = "../modules/backend"

  # configuration goes here
}

setup.sh

#!/usr/bin/env bash

# Initialize the local Terraform backend
terraform init setup
# Set up remote backend infrastructure
terraform apply -var-file=backend.tfvars setup
# Initialize the remote Terraform backend and migrate local to remote
terraform init -backend-config=backend.tfvars base

structure.md

- backend.tfvars
- setup
-- main.tf
-- variables.tf
- base
-- main.tf (symlink to ../setup/main.tf)
-- variables.tf (symlink to ../setup/variables.tf)
-- backend.tf (symlink to ../common/backend.tf)
- common
-- backend.tf