I’ve been in a situation where I want to run sysprep on a Azure VM to create an image, hopefully without needing to login / connect directly to the VM. I thought that this was an opportunity to learn about custom script extensions. (for use in other situations as well)
in summary, I created a powershell script file, and saved it to a new file ‘sysprep.ps1’:
write-output "Sysprep Script Run, parameter 'runSysprep': $runSysprep"
write-output "starting Sysprep"
Start-Process -FilePath C:\Windows\System32\Sysprep\Sysprep.exe -ArgumentList '/generalize /oobe /shutdown /quiet'
write-output "started Sysprep"
write-output "skipping Sysprep"
I then uploaded this to a storage account, set the security on the container to ‘blob’ (there’s nothing sensitive in that script), then ran the following:
$VMName = 'vmName'
$VMRG = 'vmResourceGroup'
$VMLocation = 'AustraliaEast'
$ExtensionName = 'runsysprep'
$Scripturi = 'https://<storageAccountName>.blob.core.windows.net/templates/scripts/sysprep.ps1'
Set-AzureRmVMCustomScriptExtension -FileUri $ScriptURI -ResourceGroupName $VMRG -VMName $VMName -Name $ExtensionName -Location $VMLocation -run './scripts/sysprep.ps1' -Argument '-runSysprep'
This gave the output:
RequestId IsSuccessStatusCode StatusCode ReasonPhrase
--------- ------------------- ---------- ------------
True OK OK
To see the output messages from the script that was run:
$status = Get-AzureRmVMDiagnosticsExtension -ResourceGroupName $VMRG -VMName $VMName -Name $ExtensionName -Status
This displayed the output that was expected:
Sysprep Script Run, parameter 'runSysprep': True\nstarting Sysprep\nstarted Sysprep
A short time later, the VM is shutdown (but is still allocated & incurring charges), so i then shutdown the VM: