Run scripts in your Windows VM by using action Run Commands

The Run Command feature uses the virtual machine (VM) agent to run PowerShell scripts within an Azure Windows VM. You can use these scripts for general machine or application management. They can help you to quickly diagnose and remediate VM access and network issues and get the VM back to a good state.

Benefits

You can access your virtual machines in multiple ways. Run Command can run scripts on your virtual machines remotely by using the VM agent. You use Run Command through the Azure portal, REST API, or PowerShell for Windows VMs.

This capability is useful in all scenarios where you want to run a script within a virtual machine. It's one of the only ways to troubleshoot and remediate a virtual machine that doesn't have the RDP or SSH port open because of improper network or administrative user configuration.

Prerequisites

Windows OS’ Supported

Restrictions

The following restrictions apply when you're using Run Command:

• Output is limited to the last 4,096 bytes.
• The minimum time to run a script is about 20 seconds.
• Scripts run as System on Windows.
• One script at a time can run.
• Scripts that prompt for information (interactive mode) aren't supported.
• You can't cancel a running script.
• The maximum time a script can run is 90 minutes. After that, it will time out.
• Outbound connectivity from the VM is required to return the results of the script.
• It isn't recommended to run a script that will cause a stop or update of the VM Agent. This can let the extension in a Transitioning state, leading to a timeout.

Available commands

This table shows the list of commands available for Windows VMs. You can use the RunPowerShellScript command to run any custom script that you want. When you're using the Azure CLI or PowerShell to run a command, the value that you provide for the --command-id or -CommandId parameter must be one of the following listed values. When you specify a value that isn't an available command, you receive this error:

The entity was not found in this Azure location

Azure CLI

The following example uses the az vm run-command command to run a shell script on an Azure Windows VM.

# script.ps1
#   param(
#       [string]$arg1,
#       [string]$arg2
#   )
#   Write-Host This is a sample script with parameters $arg1 and $arg2

az vm run-command invoke  --command-id RunPowerShellScript --name win-vm -g my-resource-group \
    --scripts @script.ps1 --parameters "arg1=somefoo" "arg2=somebar"

Azure portal

Go to a VM in the Azure portal and select Run command from the left menu, under Operations. You see a list of the available commands to run on the VM.

Choose a command to run. Some of the commands might have optional or required input parameters. For those commands, the parameters are presented as text fields for you to provide the input values. For each command, you can view the script that's being run by expanding View script. RunPowerShellScript is different from the other commands, because it allows you to provide your own custom script.

After you choose the command, select Run to run the script. After the script finishes, it returns the output and any errors in the output window. The following screenshot shows an example output from running the RDPSettings command.

PowerShell

The following example uses the Invoke-AzVMRunCommand cmdlet to run a PowerShell script on an Azure VM. The cmdlet expects the script referenced in the -ScriptPath parameter to be local to where the cmdlet is being run.

Invoke-AzVMRunCommand -ResourceGroupName '<myResourceGroup>' -Name '<myVMName>' -CommandId 'RunPowerShellScript' -ScriptPath '<pathToScript>' -Parameter @{"arg1" = "var1";"arg2" = "var2"}

Limiting access to Run Command

Listing the run commands or showing the details of a command requires the Microsoft.Compute/locations/runCommands/read permission on Subscription Level. The built-in Reader role and higher levels have this permission.

Running a command requires the Microsoft.Compute/virtualMachines/runCommands/action permission. The Virtual Machine Contributor role and higher levels have this permission.

You can use one of the built-in roles or create a custom role to use Run Command.

Action Run Command Windows troubleshooting

When troubleshooting action run command for Windows environments, refer to the RunCommandExtension log file typically located in the following directory: C:\WindowsAzure\Logs\Plugins\Microsoft.CPlat.Core.RunCommandWindows\<version>\RunCommandExtension.log for further details.

Known issues

• Your Action Run Command Extension might fail to execute in your Windows environment if the command contains reserved characters. For example:

  If the & symbol is passed in the parameter of your command such as the below PowerShell script, it might fail.

  $paramm='abc&jj'
  Invoke-AzVMRunCommand -ResourceGroupName AzureCloudService1 -Name test -CommandId 'RunPowerShellScript' -ScriptPath     C:\data\228332902\PostAppConfig.ps1 -Parameter @{"Prefix" = $paramm}
  

  Use the ^ character to escape the & in the argument, such as $paramm='abc^&jj'

• The Run Command extension might also fail to execute if command to be executed contains "\n" in the path, as it will be treated as a new line. For example, C:\Windows\notepad.exe contains the \n in the file path. Consider replacing \n with \N in your path.

• Ensure you don't have any custom setting in the registry key HKLM\SOFTWARE\Microsoft\Command Processor\AutoRun (detailed here). This could trigger during the RunCommand Extension install or enable phases and cause an error like 'XYZ is not recognized as an internal or external command, operable program or batch file'.

Action Run Command Removal

If needing to remove your action run command Windows extension, refer to the below steps for Azure PowerShell and CLI:

Replace rgname and vmname with your relevant resource group name and virtual machine name in the following removal examples.

 Invoke-AzVMRunCommand -ResourceGroupName 'rgname' -VMName 'vmname' -CommandId 'RemoveRunCommandWindowsExtension'

az vm run-command invoke  --command-id RemoveRunCommandWindowsExtension --name vmname -g rgname

Next steps

To learn about other ways to run scripts and commands remotely in your VM, see Run scripts in your Windows VM.