azurerm_linux_virtual_machine_scale_set - update error

[ArcturusZhang]

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Terraform (and AzureRM Provider) Version

Terraform v0.12.29

Affected Resource(s)

• azurerm_linux_virtual_machine_scale_set
• probably azurerm_windows_virtual_machine_scale_set

Terraform Configuration Files

resource "azurerm_linux_virtual_machine_scale_set" "main" {
  name                            = "${var.prefix}-vmss"
  resource_group_name             = data.azurerm_resource_group.test.name
  location                        = data.azurerm_resource_group.test.location
  sku                             = "Standard_F2"
  instances                       = 3
  admin_username                  = "adminuser"
  admin_password                  = "P@ssw0rd1234!"
  disable_password_authentication = false

  source_image_id = data.azurerm_shared_image_version.test.id

  network_interface {
    name    = "example"
    primary = true

    ip_configuration {
      name      = "internal"
      primary   = true
      subnet_id = azurerm_subnet.internal.id
    }
  }

  os_disk {
    storage_account_type = "Standard_LRS"
    caching              = "ReadWrite"
  }
  
  data_disk {
    storage_account_type = "Standard_LRS"
    caching              = "ReadOnly"
    lun                  = 1
    disk_size_gb         = 20
    create_option        = "Empty"
  }

  tags = {
    "Test" = "Foo"
  }
}

Debug Output

Panic Output

Error updating LLinuxinux Virtual Machine Scale Set "test-vmss" (Resource Group "test-vmss-update"): compute.VirtualMachineScaleSetsClient#Update: Failure sending request: StatusCode=400 -- Original Error: Code="InvalidParameter" Message="Required parameter 'imageReference' is missing (null)." Target="imageReference"

Expected Behavior

The VMSS successfully updated

Actual Behavior

Got an error complaining imageReference is null

Error updating LLinuxinux Virtual Machine Scale Set "test-vmss" (Resource Group "test-vmss-update"): compute.VirtualMachineScaleSetsClient#Update: Failure sending request: StatusCode=400 -- Original Error: Code="InvalidParameter" Message="Required parameter 'imageReference' is missing (null)." Target="imageReference"

Steps to Reproduce

1. terraform apply with the config above but the data_disk block removed - the VMSS should be successfully provisioned
2. terraform apply again with the config above with data_disk block restored - service throws an error at you

Important Factoids

I believe this should be an Azure API bug - in some circumstances, the API is expected in a PATCH request, even though you are not willing to change the image reference, you will have to specify an image reference.

But a workaround on the provider side is also valid - just always fill in the image reference in the update callback

References

• AzureRM and VMSS - update error #7253

[ArcturusZhang]

Upstream issue opened: Azure/azure-rest-api-specs#10322

[ghost]

This has been released in version 2.26.0 of the provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading. As an example:

provider "azurerm" {
    version = "~> 2.26.0"
}
# ... other configuration ...

[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!