How to update a VM Application from a Compute Gallery on a VM Scale Set ?

Question

Hello !

I need to deploy an application in a Virtual Machine Scale Set, thus I have chosen to use VM Applications from Compute Gallery as it went recently GA.
It looks great as it provides a way to install and update an application on a VMSS (as I need to provide commands for installation, uninstallation and update when create a version of my VM Application).
For now I can automate the creation of the VMSS and the installation of a VM Application version, but I can't find a way to update the VM Application to a new version on my VMSS.
The following page explains how to install a VM Application but there is nothing about updating...

Honestly I am wondering if this is possible as there is apparently no PowerShell cmdlet to do it...
I have tried to do it using the portal and Azure CLI, the result is always the same: the change is accepted but once "done" the previous version is still in place :-/

I hope I am missing something on this and will appreciate any help :)
I am strongly hesitating to move to a Custom Script Extension :)

Answer 1

Hello @XavierM ,

So essentially, you'll need to setup/install the new app version or run the deployment of the new app version on any VM or VMSS instance and it should update if that exists on the current iteration, or it will remove the old version and install the new one.

This is simply deploying the application again as if you were deploying the first time. The difference is that if it is already there it should use the update command that you provided on the first install of the app. If that update command doesn't exist, it will remove the old version and install the new version using the remove/install commands.

Hope this helps? Please feel free to reach back if you have any question. Tag me in you response. Thanks.

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