Ephemeral OS disk examples use ReadWrite caching

[nathanweeks]

Is there an existing issue for this?

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Terraform Version

1.6.4

AzureRM Provider Version

3.96.0

Affected Resource(s)/Data Source(s)

azurerm_linux_virtual_machine, azurerm_windows_virtual_machine, azurerm_linux_virtual_machine_scale_set, azurerm_windows_virtual_machine_scale_set

Terraform Configuration Files

https://github.com/hashicorp/terraform-provider-azurerm/tree/7f80c0bb23fe7835ded5e88c3217bdaef071a615/examples/virtual-machines/linux/ephemeral-os-disk

Debug Output/Panic Output

Error: expanding `os_disk`: `diff_disk_settings` can only be set when `caching` is set to `ReadOnly`
           with azurerm_linux_virtual_machine.main,
           on main.tf line 39, in resource "azurerm_linux_virtual_machine" "main":
           resource "azurerm_linux_virtual_machine" "main" {

Expected Behaviour

The ephemeral OS disk examples use ReadWrite caching, which is not allowed when diff_disk_settings is used to enable ephemeral OS disk:

terraform-provider-azurerm/examples/vm-scale-set/linux/ephemeral-os-disk/main.tf

Line 57 in 7f80c0b

caching = "ReadWrite"

terraform-provider-azurerm/examples/virtual-machines/linux/ephemeral-os-disk/main.tf

Line 60 in 7f80c0b

caching = "ReadWrite"

terraform-provider-azurerm/examples/vm-scale-set/windows/ephemeral-os-disk/main.tf

Line 57 in 7f80c0b

caching = "ReadWrite"

terraform-provider-azurerm/examples/virtual-machines/windows/ephemeral-os-disk/main.tf

Line 60 in 7f80c0b

caching = "ReadWrite"

The examples should be updated to use ReadOnly caching.

Actual Behaviour

No response

Steps to Reproduce

terraform apply -auto-approve -var location=eastus -var prefix=test

Important Factoids

No response

References

terraform-provider-azurerm/website/docs/r/linux_virtual_machine.html.markdown

Line 303 in 7f80c0b

-> **NOTE:** `diff_disk_settings` can only be set when `caching` is set to `ReadOnly`. More information can be found [here](https://docs.microsoft.com/azure/virtual-machines/ephemeral-os-disks-deploy#vm-template-deployment)