Ability to specify LUN and Caching for additional Azure data disks on managed image

[ukienet]

Overview

Since version 1.2.2 packer supports building with additional disks.

I tested this new feature by creating a template that creates additional 127GB managed data disk. After I ran the template I found out that packer defaults certain values for data disks:

1. LUN is defaulted to 0. I assume that adding more disks will increment LUN to 1, 2, etc.
2. Caching is set to Read/Write on attached disks.

Problem

Once Azure Manager disk is created, it is not possible to change properties of the attached disk in the managed image. For example, Azure CLI does not offer commands to change property of data disk in managed image. Likewise, Azure Powershell, does not offer cmd-lets to change properties of data disk in managed image. I tired changing Lun via powershell in Azure Cloud Shell and received the following error

1. I need to change LUN from 0 to 1 on a single data disk created with the managed disk using packer version 1.2.2. This is the requirement of the Azure Scale Set infrastructure we run.
2. I also need to set caching to Read-only according to recommendations: https://docs.microsoft.com/en-us/azure/virtual-machines/windows/premium-storage-performance#disk-caching

Feature Requested

Enhance packer to allow setting LUN and cache value for data disks before creating managed image.

[ghost]

This issue has been automatically migrated to hashicorp/packer-plugin-azure#19 because it looks like an issue with that plugin. If you believe this is not an issue with the plugin, please reply to hashicorp/packer-plugin-azure#19.