azurerm_[orchestrated|windows|linux]_virtual_machine_scale_set: support placement for os disks

[sergelogvinov]

Add option placement to diff_disk_settings block.

Code was copied from virtual_machine.go

  os_disk {
    caching              = "ReadOnly"
    storage_account_type = "Standard_LRS"

    diff_disk_settings {
      option    = "Local"
      placement = "ResourceDisk"
    }
  }

[katbyte]

Thanks for the pr @sergelogvinov - we'll need to update the docs with the new property as well add it to a test. thanks

[sergelogvinov]

I've update the docs/tests, and add windows_virtual_machine_scale_set support too.

[sergelogvinov]

Hello @katbyte can you add it in a future release? Most of it is copy/past.

[stephybun]

Thanks for this PR @sergelogvinov, unfortunately we have a test failure. The default value might need to be removed?

------- Stdout: -------
=== RUN   TestAccLinuxVirtualMachineScaleSet_disksOSDiskEphemeral
=== PAUSE TestAccLinuxVirtualMachineScaleSet_disksOSDiskEphemeral
=== CONT  TestAccLinuxVirtualMachineScaleSet_disksOSDiskEphemeral
testcase.go:110: Step 1/2 error: After applying this test step, the plan was not empty.
stdout:
Terraform used the selected providers to generate the following execution
plan. Resource actions are indicated with the following symbols:
-/+ destroy and then create replacement
Terraform will perform the following actions:
# azurerm_linux_virtual_machine_scale_set.test must be replaced
-/+ resource "azurerm_linux_virtual_machine_scale_set" "test" {
~ computer_name_prefix                              = "acctestvmss-220626211113595156" -> (known after apply)
- encryption_at_host_enabled                        = false -> null
~ id                                                = "/subscriptions/*******/resourceGroups/acctestRG-220626211113595156/providers/Microsoft.Compute/virtualMachineScaleSets/acctestvmss-220626211113595156" -> (known after apply)
name                                              = "acctestvmss-220626211113595156"
~ platform_fault_domain_count                       = 0 -> (known after apply)
- secure_boot_enabled                               = false -> null
~ unique_id                                         = "616bcf0e-1720-47d4-94da-da801a213b92" -> (known after apply)
- vtpm_enabled                                      = false -> null
# (17 unchanged attributes hidden)
~ automatic_instance_repair {
~ enabled      = false -> (known after apply)
~ grace_period = "PT30M" -> (known after apply)
}
+ extension {
+ auto_upgrade_minor_version = (known after apply)
+ automatic_upgrade_enabled  = (known after apply)
+ force_update_tag           = (known after apply)
+ name                       = (known after apply)
+ protected_settings         = (sensitive value)
+ provision_after_extensions = (known after apply)
+ publisher                  = (known after apply)
+ settings                   = (known after apply)
+ type                       = (known after apply)
+ type_handler_version       = (known after apply)
}
~ network_interface {
name                          = "example"
# (3 unchanged attributes hidden)
# (1 unchanged block hidden)
}
~ os_disk {
~ disk_size_gb              = 30 -> (known after apply)
# (3 unchanged attributes hidden)
~ diff_disk_settings {
+ placement = "CacheDisk" # forces replacement
# (1 unchanged attribute hidden)
}
}
+ terminate_notification {
+ enabled = (known after apply)
+ timeout = (known after apply)
}
+ termination_notification {
+ enabled = (known after apply)
+ timeout = (known after apply)
}
# (1 unchanged block hidden)
}
Plan: 1 to add, 0 to change, 1 to destroy.
--- FAIL: TestAccLinuxVirtualMachineScaleSet_disksOSDiskEphemeral (319.10s)
FAIL

[sergelogvinov]

@stephybun thank you for feedback. Yep, my bad. I did not test well.

Now all fine.

[katbyte]

LGTM 🌵

[github-actions]

This functionality has been released in v3.14.0 of the Terraform Provider. Please see the Terraform documentation on provider versioning or reach out if you need any assistance upgrading.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template. Thank you!

[NillsF]

@stephybun
This change impacted my Terraform code for Linux scale sets. The default of CacheDisk didn't work, and I was able to solve by setting:

diff_disk_settings {
      option    = "Local"
      placement = "ResourceDisk"
    }

I wonder if setting the default to ResourceDisk might be a better default value.

[sergelogvinov]

Hello. Can you tell me what instance type/region do you use?

[NillsF]

standard_e32ads_v5 in East US.

[sergelogvinov]

Yep, maybe you a right. I did not find the cache size here eads-v5 either.

All my instances eads-v4 use Temp storage too.

So, I vote for your idea )

[github-actions]

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If you have found a problem that seems related to this change, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.