How to Import an Google Compute Persistent Disk into Terraform

Import Google Compute Persistent Disk with Terraback (recommended)

Terraback reverse-engineers your live infrastructure: it reads the Compute Engine resource with read-only credentials, generates the HCL, and produces the exact import block. Two commands take you from a live Google Compute Persistent Disk to managed Terraform.

terraback scan all gcp --project my-gcp-project

terraback gcp import --method bulk

The Terraform import block

Terraback emits a Terraform 1.5+ import block like the one below. Because the block lives in your configuration, the import is reviewable in a pull request and repeatable across environments.

import {
  to = google_compute_disk.data
  id = "projects/my-project/zones/us-central1-a/disks/data-disk"
}

Example google_compute_disk configuration

Here is a realistic Google Compute Persistent Disk block. Terraback generates a fuller version from your actual resource attributes; this is a minimal, valid starting point.

resource "google_compute_disk" "data" {
  name    = "data-disk"
  type    = "pd-ssd"
  zone    = "us-central1-a"
  size    = 100
  project = "my-project"
}

Gotchas when importing a Google Compute Persistent Disk

• google_compute_disk is zonal and uses a zones/<zone> path; a regional disk is the separate google_compute_region_disk resource.
• If the disk is attached to an instance, the attachment is normally managed through the instance boot_disk or attached_disk, not duplicated here.
• Shrinking size is not allowed; size can only grow, and changing type or zone forces recreation.
• image and snapshot are creation-time source fields that are not returned on import, so omit them unless you need to recreate the disk.

Doing it manually with terraform import

The native approach is to write the google_compute_disk block by hand, then run terraform import google_compute_disk.example <import-id> for every resource, one at a time. That works for a handful of resources, but it does not scale: you author all the HCL yourself and repeat the command for each item. Terraback generates the HCL and the import blocks for your whole account in one pass.

Import other Google Cloud resources