Tutorial: Create multiple resource instances with ARM templates

Learn how to iterate in your Azure Resource Manager template (ARM template) to create multiple instances of an Azure resource. In this tutorial, you modify a template to create three storage account instances.

Azure Resource Manager creates multiple instances diagram

This tutorial covers the following tasks:

  • Open a Quickstart template
  • Edit the template
  • Deploy the template

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

Prerequisites

To complete this article, you need:

Open a Quickstart template

Azure Quickstart Templates is a repository for ARM templates. Instead of creating a template from scratch, you can find a sample template and customize it. The template used in this quickstart is called Create a standard storage account. The template defines an Azure Storage account resource.

  1. From Visual Studio Code, select File > Open File.

  2. In File name, paste the following URL:

    https://raw.githubusercontent.com/Azure/azure-quickstart-templates/master/quickstarts/microsoft.storage/storage-account-create/azuredeploy.json
    
  3. Select Open to open the file.

  4. There is a 'Microsoft.Storage/storageAccounts' resource defined in the template.

  5. Select File > Save As to save the file as azuredeploy.json to your local computer.

Edit the template

The existing template creates one storage account. You customize the template to create three storage accounts.

From Visual Studio Code, make the following four changes:

Azure Resource Manager creates multiple instances

  1. Add a copy element to the storage account resource definition. In the copy element, you specify the number of iterations and a variable for this loop. The count value must be a positive integer and can't exceed 800.
  2. The copyIndex() function returns the current iteration in the loop. You use the index as the name prefix. copyIndex() is zero-based. To offset the index value, you can pass a value in the copyIndex() function. For example, copyIndex(1).
  3. Delete the variables element, because it's not used anymore.
  4. Delete the outputs element. It's no longer needed.

The completed template looks like:

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "storageAccountType": {
      "type": "string",
      "defaultValue": "Standard_LRS",
      "allowedValues": [
        "Standard_LRS",
        "Standard_GRS",
        "Premium_LRS"
      ],
      "metadata": {
        "description": "Storage Account type"
      }
    },
    "location": {
      "type": "string",
      "defaultValue": "[resourceGroup().location]",
      "metadata": {
        "description": "Location for all resources."
      }
    }
  },
  "resources": [
    {
      "type": "Microsoft.Storage/storageAccounts",
      "apiVersion": "2019-04-01",
      "name": "[concat(copyIndex(),'storage', uniqueString(resourceGroup().id))]",
      "location": "[parameters('location')]",
      "sku": {
        "name": "[parameters('storageAccountType')]"
      },
      "kind": "StorageV2",
      "copy": {
        "name": "storagecopy",
        "count": 3
      },
      "properties": {}
    }
  ]
}

For more information about creating multiple instances, see Resource iteration in ARM templates

Deploy the template

  1. Check the file you saved in the previous section.

  2. From the local Shell, run the following commands. Select the tab to show the PowerShell code or the CLI code.

    Note

    Before you can use Azure CLI in Azure China 21Vianet, please run az cloud set -n AzureChinaCloud first to change the cloud environment. If you want to switch back to Azure Public Cloud, run az cloud set -n AzureCloud again.

    echo "Enter a project name that is used to generate resource group name:" &&
    read projectName &&
    echo "Enter the location (i.e. chinaeast):" &&
    read location &&
    resourceGroupName="${projectName}rg" &&
    az group create --name $resourceGroupName --location "$location" &&
    az deployment group create --resource-group $resourceGroupName --template-file "$HOME/azuredeploy.json"
    

After a successful template deployment you can display the three storage accounts created in the specified resource group. Compare the storage account names with the name definition in the template.

echo "Enter a project name that is used to generate resource group name:" &&
read projectName &&
resourceGroupName="${projectName}rg" &&
az storage account list --resource-group $resourceGroupName &&
echo "Press [ENTER] to continue ..."

Clean up resources

When the Azure resources are no longer needed, clean up the resources you deployed by deleting the resource group.

  1. From the Azure portal, select Resource group from the left menu.
  2. Enter the resource group name in the Filter by name field.
  3. Select the resource group name. You shall see a total of three resources in the resource group.
  4. Select Delete resource group from the top menu.

Next steps

In this tutorial, you learned how to create multiple storage account instances. In the next tutorial, you develop a template with multiple resources and multiple resource types. Some of the resources have dependent resources.