Modifiable Alias missing for Microsoft.Compute/virtualMachines/extensions

[XristophD]

Hello, I am trying to deploy configurations on VirtualMachine Extensions via Azure Policies, but I am missing aliases to deploy the updates.

In detail, I need to update the policy I try to deploy looks like the following:

{ "properties": { "displayName": "Enable AzureMonitor Extension AutoUpgrade", "mode": "Indexed", "description": "This policy enables the automatic upgrade of Azure Monitor Extensions.", "metadata": { "category": "Monitoring" }, "parameters": { "effect": { "type": "string", "metadata": { "displayName": "Effect", "description": "Enable or disable the execution of the policy." }, "allowedValues": ["Modify", "Disabled"], "defaultValue": "Modify" } }, "policyRule": { "if": { "allOf": [ { "field": "Microsoft.Compute/virtualMachines/extensions/type", "equals": "AzureMonitorWindowsAgent" }, { "field": "Microsoft.Compute/virtualMachines/extensions/publisher", "equals": "Microsoft.Azure.Monitor" }, { "field": "Microsoft.Compute/virtualMachines/extensions/provisioningState", "equals": "Succeeded" }, { "field": "Microsoft.Compute/virtualMachines/extensions/enableAutomaticUpgrade", "equals": false } ] }, "then": { "effect": "[parameters('effect')]", "details": { "conflictEffect": "audit", "roleDefinitionIds": [ "/providers/microsoft.authorization/roleDefinitions/9980e02c-c2be-4d73-94e8-173b1dc7cf3c" ], "operations": [ { "condition": "[greaterOrEquals(requestContext().apiVersion, '2020-06-01')]", "operation": "addOrReplace", "field": "Microsoft.Compute/virtualMachines/extensions/enableAutomaticUpgrade", "value": true } ] } } } } }

The used field "Microsoft.Compute/virtualMachines/extensions/enableAutomaticUpgrade" is not available in the listing of modifiable aliases for Virtual Machines, the policy deployment therefore fails with the following error:

I found, this alias is available for VirtualMachineScaleSets:

Is there a reason this is missing for Virtual Machines? Is there a timeline bringing making this alias available (and modifiable)?

Best Regards Christoph