Description of problem

The Machine API Operator does not apply boot diagnostics to Azure VMs on Azure Stack Hub, even when the Machine spec correctly specifies diagnostics configuration. The created Azure VM shows "diagnosticsProfile": null despite the Machine and MachineSet having correct diagnostics settings.

Root cause:
The deriveVirtualMachineParametersStackHub function in pkg/cloud/azure/services/virtualmachines/virtualmachines_stack.go is missing the line DiagnosticsProfile: vmSpec.DiagnosticsProfile. This field has been missing from the StackHub implementation since boot diagnostics were added to the public cloud version. When commit afd0f3f9 (OCPBUGS-55372) unified the StackHub and public cloud implementations, it preserved this pre-existing gap. The regular (non-StackHub) function has this field at line 280, but it is completely missing from the StackHub version.

Version-Release number

4.22

How reproducible

Always

Steps to Reproduce

Create a MachineSet on Azure Stack Hub with boot diagnostics configuration:

diagnostics:
  boot:
    customerManaged:
      storageAccountURI: [https://storage.blob.example.com|https://storage.blob.example.com]
    storageAccountType: CustomerManaged

Create a Machine from the MachineSet

Wait for the Machine to be provisioned

Check the Azure VM diagnostics profile:

az vm show \-n  \-g  \-\-query "diagnosticsProfile"

Actual results

The Azure VM shows:

"diagnosticsProfile": null

Boot diagnostics are not enabled on the VM, even though the Machine resource shows the correct diagnostics configuration in its spec.

Expected results

The Azure VM should have boot diagnostics configured:

"diagnosticsProfile": {
  "bootDiagnostics": {
    "enabled": true,
    "storageUri": "[https://storage.blob.example.com"|https://storage.blob.example.com"]
  }
}

Example failed job

For detailed MachineSet and Machine status, see:
https://qe-private-deck-ci.apps.ci.l2s4.p1.openshiftapps.com/view/gs/qe-private-deck/pr-logs/pull/openshift_release/73625/rehearse-73625-periodic-ci-openshift-verification-tests-main-installation-nightly-4.22-azure-stack-ipi-boot-diagnostics-usermanaged-f28/2013057286183849984