Terraform import, moved and removed

Importing existing resources

Since Terraform 1.5, import is declared in code and shows up in the plan:

import {
  to = aws_s3_bucket.legacy
  id = "acme-legacy-uploads"
}

resource "aws_s3_bucket" "legacy" {
  bucket = "acme-legacy-uploads"
}

terraform plan -generate-config-out=generated.tf can even write the resource block for you. Since 1.16, import blocks also work inside modules.

Renaming without destroying: moved

Renaming aws_instance.web to aws_instance.frontend would normally destroy one and create the other. A moved block tells Terraform it is the same object:

moved {
  from = aws_instance.web
  to   = aws_instance.frontend
}

Stop managing without deleting: removed

removed {
  from = aws_instance.old_bastion
  lifecycle {
    destroy = false   # forget it in state, keep the real server
  }
}

terraform {
  required_providers {
    local = { source = "hashicorp/local", version = "~> 2.5" }
  }
}

resource "local_file" "renamed" {
  filename = "${path.module}/notes.txt"
  content  = "kept"
}

moved {
  from = local_file.original
  to   = local_file.renamed
}

Terraform will perform the following actions:

  # local_file.renamed will be created
  + resource "local_file" "renamed" {
      + content              = "kept"
      + content_base64sha256 = (known after apply)
      + content_base64sha512 = (known after apply)
      + content_md5          = (known after apply)
      + content_sha1         = (known after apply)
      + content_sha256       = (known after apply)
      + content_sha512       = (known after apply)
      + directory_permission = "0777"
      + file_permission      = "0777"
      + filename             = "./notes.txt"
      + id                   = (known after apply)
    }

Plan: 1 to add, 0 to change, 0 to destroy.