Grant least-privilege list access to Compute images and disks for an external user in a project. What should you do?

The correct approach is to create a custom IAM role with only the necessary permissions: compute.disks.list and compute.images.list. Granting this custom role at the project level ensures the user can list all images and disks within that project without having broader, unnecessary permissions. This adheres to the principle of least privilege, minimizing potential security risks. The other options are incorrect because they grant excessive permissions: Creating a custom role based on roles/compute.imageUser would include more permissions than just listing, such as creating and deleting images. Basing a role on roles/storage.admin is entirely incorrect as it pertains to Cloud Storage, not Compute Engine resources, and would grant extensive permissions to storage buckets. Directly granting roles/storage.admin at the project level is also incorrect for the same reason and provides far too much access.