Sample - Not allowed VM extensions

Prohibits the use of specified extensions. You specify an array containing the prohibited extension types.

If you don't have an Azure subscription, create a free account before you begin.

Sample template

{
    "properties": {
        "displayName": "Not allowed VM Extensions",
        "description": "This policy governs which VM extensions that are explicitly denied.",
        "parameters": {
            "notAllowedExtensions": {
                "type": "Array",
                "metadata": {
                    "description": "The list of extensions that will be denied. Example: BGInfo, CustomScriptExtension, JsonAADDomainExtension, VMAccessAgent.",
                    "displayName": "Denied extension"
                }
            }
        },
        "policyRule": {
            "if": {
                "allOf": [
                    {
                        "field": "type",
                        "equals": "Microsoft.Compute/virtualMachines/extensions"
                    },
                    {
                        "field": "Microsoft.Compute/virtualMachines/extensions/publisher",
                        "equals": "Microsoft.Compute"
                    },
                    {
                        "field": "Microsoft.Compute/virtualMachines/extensions/type",
                        "in": "[parameters('notAllowedExtensions')]"
                    }
                ]
            },
            "then": {
                "effect": "deny"
            }
        }
    }
}

You can deploy this template using the Azure portal, with PowerShell or with the Azure CLI.

Deploy with the portal

Deploy the Policy sample to Azure

Deploy with PowerShell

This sample requires Azure PowerShell. Run Get-Module -ListAvailable Az to find the version. If you need to install or upgrade, see Install Azure PowerShell module.

Run the Connect-AzAccount cmdlet to connect to Azure.

$definition = New-AzPolicyDefinition -Name "not-allowed-vmextension" -DisplayName "Not allowed VM Extensions" -description "This policy governs which VM extensions that are explicitly denied." -Policy 'https://raw.githubusercontent.com/Azure/azure-policy/master/samples/Compute/not-allowed-vmextension/azurepolicy.rules.json' -Parameter 'https://raw.githubusercontent.com/Azure/azure-policy/master/samples/Compute/not-allowed-vmextension/azurepolicy.parameters.json' -Mode All
$definition
$assignment = New-AzPolicyAssignment -Name <assignmentname> -Scope <scope>  -notAllowedExtensions <Denied extension> -PolicyDefinition $definition
$assignment

Clean up PowerShell deployment

Run the following command to remove the resource group, VM, and all related resources.

Remove-AzResourceGroup -Name myResourceGroup

Deploy with Azure CLI

To run this sample, install the latest version of the Azure CLI. To start, run az login to create a connection with Azure.

Samples for the Azure CLI are written for the bash shell. To run this sample in Windows PowerShell or Command Prompt, you may need to change elements of the script.

az policy definition create --name 'not-allowed-vmextension' --display-name 'Not allowed VM Extensions' --description 'This policy governs which VM extensions that are explicitly denied.' --rules 'https://raw.githubusercontent.com/Azure/azure-policy/master/samples/Compute/not-allowed-vmextension/azurepolicy.rules.json' --params 'https://raw.githubusercontent.com/Azure/azure-policy/master/samples/Compute/not-allowed-vmextension/azurepolicy.parameters.json' --mode All

az policy assignment create --name <assignmentname> --scope <scope> --policy "not-allowed-vmextension"

Clean up Azure CLI deployment

Run the following command to remove the resource group, VM, and all related resources.

az group delete --name myResourceGroup --yes

Next steps