How to start/stop a virtual machine scale set instance

There are so many auto shutdown scripts available to manage single instance Azure virtual machines, but how do we manage the snoozing / user defined scheduling of instances in virtual machine scale sets in non-production environments as part of FinOps.

Stand-alone virtual machines can be snoozed via the auto-shutdown feature or via the automation tasks. You also have the option to configure the start/stop plan in the marketplace for a scaled solution across multiple availability zones, multiple subcriptions and resource groups.

None of these solutions are however capable of managing virtual machine scale set instances. So how do we configure user defined schedules for virtual machine instances inside a virtual machine scale set? These instances have no Automation Tasks and the start/stop plan does not work on these instances. So I configured an Azure Automation Runbook specifically for virtual machine scale set instances.

Depolyment Plan

Step 1 – Create an Azure Automation Account
Step 2 – Provision the SAMI
Step 3 – Assign the SAMI Role
Step 4 – Import the Necessary PowerShell Modules
Step 5 – Create 2 Runbooks
Step 6 – Information Gathering
Step 7 – Add the PowerShell START script
Step 8 – Creating your STOP powershell script

Deployment Steps

Step 1 - Create an Azure Automation Account

Step 2 - Provision the SAMI

Go to your Automation Account > Identity > System Assigned tab > make sure the SAMI is ON,

Step 3 - Assign the SAMI Role

Click on Azure Role Assignments button > Add role assignment  > select your scope and role based on PoLP

Step 4 - Import the Necessary PowerShell Modules

You may need to install the Connect-AzAccount module for your powershell script.

Click on Modules > Add a Module > select Browse from gallery > click here to browse from gallery > enter Connect-AzAccount >

Click on the Az.Accounts module

On the content page > populate the search bar with your required command to ensure that the command is included in the module.

Go to Automation account > Modules > search and install the required modules required by your PowerShell script >

Select > choose a runtime version that is not in preview > Import.

You can then do a search on the module name to verify its importation.

Step 5 - Create 2 Runbooks

Step 6  - Information Gathering

1.1 Use powershell to view / collect all the high-level information about your target scale set:

1.2 To get a view of all the instances in your vm scale set:

Step 7 - Add the PowerShell START script

Expand your Runbook and find your new START Runbook >

Copy and paste your prepared PowerShell script into the window,

Add the following powershell script to your runbook:

Create a schedule for your startup runbook,

Go to Runbook > Schedule > Add a schedule > link a schedule to your runbook >

Step 8 - Creating your STOP powershell script

Expand your Runbook and find your new STOP Runbook >

Add the following powershell script to your runbook:

This will successfully allow you to schedule the start up and shutdown of your virtual machine scale set instances using user defined scheduling.

Additional helpful management scripts

Additional useful powershell commands for managing your virtual machine scale set instances: