How to Import an Google Compute Image into Terraform

Import Google Compute Image 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 Image 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_image.base
  id = "projects/my-project/global/images/base-2024-01"
}

Example google_compute_image configuration

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

resource "google_compute_image" "base" {
  name        = "base-2024-01"
  project     = "my-project"
  family      = "base"
  source_disk = "projects/my-project/zones/us-central1-a/disks/golden"
}

Gotchas when importing a Google Compute Image

• Custom images are global resources; the import path uses global/images even though the source disk is zonal.
• Only one source (source_disk, source_image, or source_snapshot) applies, and these creation-time fields are not returned on import.
• Changing the source or most other fields forces a new image; images are effectively immutable once created.
• Public images from projects like debian-cloud are referenced, not imported into your own state.

Doing it manually with terraform import

The native approach is to write the google_compute_image block by hand, then run terraform import google_compute_image.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