Deploy Azure Policy to delegated subscriptions at scale
As a service provider, you may have onboarded multiple customer tenants to Azure Lighthouse. Azure Lighthouse allows service providers to perform operations at scale across several tenants at once, making management tasks more efficient.
This topic explains how to use Azure Policy to deploy a policy definition and policy assignment across multiple tenants using PowerShell commands. In this example, the policy definition ensures that storage accounts are secured by allowing only HTTPS traffic. You can use the same general process for any policy that you want to deploy.
Tip
Though we refer to service providers and customers in this topic, enterprises managing multiple tenants can use the same processes.
Use Azure Resource Graph to query across customer tenants
You can use Azure Resource Graph to query across all subscriptions in customer tenants that you manage. In this example, we'll identify any storage accounts in these subscriptions that don't currently require HTTPS traffic.
$MspTenant = "insert your managing tenantId here"
$subs = Get-AzSubscription
$ManagedSubscriptions = Search-AzGraph -Query "ResourceContainers | where type == 'microsoft.resources/subscriptions' | where tenantId != '$($mspTenant)' | project name, subscriptionId, tenantId" -subscription $subs.subscriptionId
Search-AzGraph -Query "Resources | where type =~ 'Microsoft.Storage/storageAccounts' | project name, location, subscriptionId, tenantId, properties.supportsHttpsTrafficOnly" -subscription $ManagedSubscriptions.subscriptionId | convertto-json
Deploy a policy across multiple customer tenants
The following example shows how to use an Azure Resource Manager template to deploy a policy definition and policy assignment across delegated subscriptions in multiple customer tenants. This policy definition requires all storage accounts to use HTTPS traffic. It prevents the creation of any new storage accounts that don't comply. Any existing storage accounts without the setting are marked as noncompliant.
Write-Output "In total, there are $($ManagedSubscriptions.Count) delegated customer subscriptions to be managed"
foreach ($ManagedSub in $ManagedSubscriptions)
{
Select-AzSubscription -SubscriptionId $ManagedSub.subscriptionId
New-AzSubscriptionDeployment -Name mgmt `
-Location eastus `
-TemplateUri "https://raw.githubusercontent.com/Azure/Azure-Lighthouse-samples/master/templates/policy-enforce-https-storage/enforceHttpsStorage.json" `
-AsJob
}
Note
While you can deploy policies across multiple tenants, currently you can't view compliance details for non-compliant resources in these tenants.
Validate the policy deployment
After you've deployed the Azure Resource Manager template, confirm that the policy definition was successfully applied by attempting to create a storage account with EnableHttpsTrafficOnly set to false in one of your delegated subscriptions. Because of the policy assignment, you should be unable to create this storage account.
New-AzStorageAccount -ResourceGroupName (New-AzResourceGroup -name policy-test -Location eastus -Force).ResourceGroupName `
-Name (get-random) `
-Location eastus `
-EnableHttpsTrafficOnly $false `
-SkuName Standard_LRS `
-Verbose
Clean up resources
When you're finished, you can remove the policy definition and assignment created by the deployment.
foreach ($ManagedSub in $ManagedSubscriptions)
{
select-azsubscription -subscriptionId $ManagedSub.subscriptionId
Remove-AzSubscriptionDeployment -Name mgmt -AsJob
$Assignment = Get-AzPolicyAssignment | where-object {$_.Name -like "enforce-https-storage-assignment"}
if ([string]::IsNullOrEmpty($Assignment))
{
Write-Output "Nothing to clean up - we're done"
}
else
{
Remove-AzPolicyAssignment -Name 'enforce-https-storage-assignment' -Scope "/subscriptions/$($ManagedSub.subscriptionId)" -Verbose
Write-Output "Deployment has been deleted - we're done"
}
}
Next steps
- Learn about Azure Policy.
- Learn about cross-tenant management experiences.
- Learn how to deploy a policy that can be remediated within a delegated subscription.