Rename folder cause deletion

[czedyousfi]

TL;DR

I used the module to create a set of folders, then I tried to rename it but instead of update-in-place, the plan announced that it would be a destroy.

Expected behavior

~ update in-place

Terraform will perform the following actions:

google_folder.department1 will be updated in-place
~ resource "google_folder" "department1" {
~ display_name = "test-folder" -> "test-folders"
id = "folders/273697474191"
name = "folders/273697474191"
# (4 unchanged attributes hidden)
}

Observed behavior

module.folders_commoncoreplatform.google_folder.folders["Prod"] will be destroyed

• resource "google_folder" "folders" {
  • create_time = "2022-01-26T10:44:19.350Z" -> null
  • display_name = "Prod" -> null
  • folder_id = "10526" -> null
  • id = "folders/1052649659043" -> null
  • lifecycle_state = "ACTIVE" -> null
  • name = "folders/10526" -> null
  • parent = "folders/6386" -> null
    }

module.folders_commoncoreplatform.google_folder.folders["Prods"] will be created

• resource "google_folder" "folders" {
  • create_time = (known after apply)
  • display_name = "Prods"
  • folder_id = (known after apply)
  • id = (known after apply)
  • lifecycle_state = (known after apply)
  • name = (known after apply)
  • parent = "folders/6386"
    }

Terraform Configuration

module "folders_commoncoreplatform" {
  source  = "terraform-google-modules/folders/google"
  version = "~> 3.0"

  parent  = "${module.folders_infra.ids["Common-Core-Platform"]}" 

  names = [
    "Dev",
    "Labs",
    "Prod"
  ]
  depends_on = [
    module.folders_infra
  ]
}

Terraform Version

1.1.4.

Additional information

No response

[morgante]

If you want to rename the folders in the Terraform state, you should use terraform state mv.

terraform state mv 'module.folders_commoncoreplatform.google_folder.folders["Prod"]' 'module.folders_commoncoreplatform.google_folder.folders["Prods"]'

[czedyousfi]

I'm going to try this then ! Thanks for your quick response

[mcdermg]

Ran into a similar issue with renaming already created folders via the module. Shouldn't the behavior of the module mimic that of the folder resource. When creating a folder with the folder resource, the folder display_name name can be updated in place

  # google_folder.department1 will be updated in-place
  ~ resource "google_folder" "department1" {
      ~ display_name    = "Department 1" -> "Department 11"
        id              = "folders/123456789"
        name            = "folders/123456789"
        # (4 unchanged attributes hidden)
    }

When doing the same with the module, create then change the name of the folder, it will destroy the folder and re create it to alter the display_name.

If a folder is created via Terrafrom via the module and renamed via the console or gcloud on a subsequent run of Terraform plan/apply it will revert the display_name with an in place change.

The module does not seem to be following the same pattern when renaming as when using a simple resource and does seem able to make an in place change in a specif circumstance if the folder is renamed outside of Terraform but not when renaming it is handled by Terraform & the module alone.

I get that terraform state mv is a possible solution but I would be interested to know why the above behavior is occurring?
Not sure if this is some limitation due to the module or the provider but having the display_name altered via an in place change would make more sense to me over a destructive action and does seem possible given the right circumstances.

[morgante]

I get that terraform state mv is a possible solution but I would be interested to know why the above behavior is occurring?

Terraform requires every resource in its state to have a "key" for mapping to the Google Cloud API. For this module, the key is the folder name so changing the name necessarily means the state location is moving.

This is a fundamental limitation of Terraform, not something that can be fixed in this module. You can work around it using terraform state mv but we can't automate state moves.

[lemoo5sg]

@morgante There is no terraform blocking topic here.
The issue with the current code version is that the folder name is used as the for_each key and this can be changed.

This has to be changed because:

• If after the initial creation, we have created resources under the folder such as projects, the deletion will fail and the renaming will never occur.
• the workaround to remove the folder from the state and delete the folder with manual action is not acceptable
• Also the potential workaround to add the new folder name as a new value in the list and keep the old name as it is is not acceptable as we do not want to keep a second folder, we need a renaming.

Proposed solution:
The variables needs to be adapted to isolate the requested folder display name from the for_each resource key to allow renaming.

For example:
instead of flat names variable, use a list such as:
names= [
{folder_key = "my_folder_1", folder_name= "requested_display_name"},
]

and for folders resource, replace toset with something similar to:
resource "google_folder" "folders" {
for_each = {for folder in var.names: folder.folder_key => folder}
display_name = "${local.prefix}${each.value.folder_name}"

This way, when we change folder_name later to "new_name", we do not change folder_key, the state key is unchanged and the folder is renamed as expected.