How to Import an Google Cloud Storage Bucket IAM Binding into Terraform

Import Google Cloud Storage Bucket IAM Binding with Terraback (recommended)

Terraback reverse-engineers your live infrastructure: it reads the Google Cloud Storage resource with read-only credentials, generates the HCL, and produces the exact import block. Two commands take you from a live Google Cloud Storage Bucket IAM Binding 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_storage_bucket_iam_binding.viewers
  id = "b/my-app-assets roles/storage.objectViewer"
}

Example google_storage_bucket_iam_binding configuration

Here is a realistic Google Cloud Storage Bucket IAM Binding block. Terraback generates a fuller version from your actual resource attributes; this is a minimal, valid starting point.

resource "google_storage_bucket_iam_binding" "viewers" {
  bucket  = google_storage_bucket.assets.name
  role    = "roles/storage.objectViewer"
  members = [
    "user:jane@example.com",
    "serviceAccount:app@my-project.iam.gserviceaccount.com",
  ]
}

Gotchas when importing a Google Cloud Storage Bucket IAM Binding

• An iam_binding is authoritative for the role on the bucket: it replaces the full member list, so omitting an existing member revokes their access.
• The import ID prefixes the bucket name with b/ and joins it to the role with a space; the bucket attribute in HCL is just the plain name.
• Granting roles/storage.objectViewer to allUsers makes objects publicly readable; review the members list carefully.
• Use google_storage_bucket_iam_member for additive grants when other systems also manage bucket IAM.

Doing it manually with terraform import

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