azurerm_virtual_machine does not update state file if disks are renumbered

[hashibot]

This issue was originally opened by @cchildress as hashicorp/terraform#9437. It was migrated here as part of the provider split. The original body of the issue is below.

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Terraform Version

0.7.3 (waiting for 0.7.6 to come out due to [GH-9122]

Affected Resource(s)

azurerm_virtual_machine

Terraform Configuration Files

Before:

  storage_data_disk {
    name = "${var.node_name}_data_disk_premium_01"
    vhd_uri = "${var.node_data_storage_account_premium_blob_endpoint}${azurerm_storage_container.node_container_data_premium.name}/${var.node_name}_data_premium_01.vhd"
    create_option = "Empty"
    disk_size_gb = 1023
    lun = 0
  }
  delete_data_disks_on_termination = true

After:

  storage_data_disk {
    name = "${var.node_name}_data_disk_standard_01"
    vhd_uri = "${var.node_data_storage_account_standard_blob_endpoint}${azurerm_storage_container.node_container_data_standard.name}/${var.node_name}_data_standard_01.vhd"
    create_option = "Empty"
    disk_size_gb = 1023
    lun = 0
  }
  storage_data_disk {
    name = "${var.node_name}_data_disk_premium_01"
    vhd_uri = "${var.node_data_storage_account_premium_blob_endpoint}${azurerm_storage_container.node_container_data_premium.name}/${var.node_name}_data_premium_01.vhd"
    create_option = "Empty"
    disk_size_gb = 1023
    lun = 32
  }
  delete_data_disks_on_termination = true

Debug Output

~ module.<some_server>.azurerm_virtual_machine.node
    storage_data_disk.0.lun:     "32" => "0"
    storage_data_disk.0.name:    "<some_server>_data_disk_premium_01" => "<some_server>_data_disk_standard_01"
    storage_data_disk.0.vhd_uri: "<foo>" => "<bar>"
    storage_data_disk.1.lun:     "0" => "32"
    storage_data_disk.1.name:    "<some_server>_data_disk_standard_01" => "<some_server>_data_disk_premium_01"
    storage_data_disk.1.vhd_uri: "<bar>" => "<foo>"

Expected Behavior

This change is successfully applied to Azure, but does not appear to be recored properly in the state file.

Actual Behavior

This shows up as a change to be made in every following terraform plan

Steps to Reproduce

1. Set up a VM using the before layout.
2. Change the Terraform config to match the after.
3. Run a terraform apply and confirm you see the changes in the Azure portal
4. Run terraform plan and the changes should be listed as pending still.

Important Factoids

I tried just editing the state file to see if it was something that could be manually corrected. Maybe I missed a spot, but I could never get it to see the change as completed.

[tombuildsstuff]

Fixed in #426

[ghost]

I'm going to lock this issue because it has been closed for 30 days ⏳. This helps our maintainers find and focus on the active issues.

If you feel this issue should be reopened, we encourage creating a new issue linking back to this one for added context. If you feel I made an error 🤖 🙉 , please reach out to my human friends 👉 hashibot-feedback@hashicorp.com. Thanks!