Azure Compute Templates

Azure Resource Manager (ARM) templates let you define the infrastructure and configuration for your Azure solutions in a declarative JSON file. This guide provides an overview of template structure, best practices, and examples specific to compute resources such as Virtual Machines, Scale Sets, and Containers.

Overview

Templates are composed of several top‑level sections:

Schema – The JSON schema that defines the template format.
Parameters – Input values that can be overridden at deployment time.
Variables – Reusable expressions derived from parameters.
Resources – The Azure resources to be provisioned.
Outputs – Values returned after deployment.

Template Schema

The schema URL must be the first property of the template. The latest schema for Azure is:

{
  "$schema": "https://schema.management.azure.com/schemas/2022-09-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  // ...
}

Sample Compute Template

The following example deploys a Windows Server virtual machine with a public IP address.

{
  "$schema": "https://schema.management.azure.com/schemas/2022-09-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "vmName": { "type": "string", "defaultValue": "myVM" },
    "adminUsername": { "type": "string", "defaultValue": "azureuser" },
    "adminPassword": { "type": "secureString" },
    "vmSize": { "type": "string", "defaultValue": "Standard_DS1_v2" }
  },
  "variables": {
    "nicName": "[concat(parameters('vmName'), '-nic')]",
    "publicIPName": "[concat(parameters('vmName'), '-pip')]"
  },
  "resources": [
    {
      "type": "Microsoft.Network/publicIPAddresses",
      "apiVersion": "2022-01-01",
      "name": "[variables('publicIPName')]",
      "location": "[resourceGroup().location]",
      "properties": {
        "publicIPAllocationMethod": "Dynamic"
      }
    },
    {
      "type": "Microsoft.Network/networkInterfaces",
      "apiVersion": "2022-01-01",
      "name": "[variables('nicName')]",
      "location": "[resourceGroup().location]",
      "dependsOn": [
        "[resourceId('Microsoft.Network/publicIPAddresses', variables('publicIPName'))]"
      ],
      "properties": {
        "ipConfigurations": [
          {
            "name": "ipconfig1",
            "properties": {
              "subnet": {
                "id": "[resourceId('Microsoft.Network/virtualNetworks/subnets', 'myVnet', 'mySubnet')]"
              },
              "publicIPAddress": {
                "id": "[resourceId('Microsoft.Network/publicIPAddresses', variables('publicIPName'))]"
              }
            }
          }
        ]
      }
    },
    {
      "type": "Microsoft.Compute/virtualMachines",
      "apiVersion": "2022-03-01",
      "name": "[parameters('vmName')]",
      "location": "[resourceGroup().location]",
      "dependsOn": [
        "[resourceId('Microsoft.Network/networkInterfaces', variables('nicName'))]"
      ],
      "properties": {
        "hardwareProfile": {
          "vmSize": "[parameters('vmSize')]"
        },
        "osProfile": {
          "computerName": "[parameters('vmName')]",
          "adminUsername": "[parameters('adminUsername')]",
          "adminPassword": "[parameters('adminPassword')]"
        },
        "storageProfile": {
          "imageReference": {
            "publisher": "MicrosoftWindowsServer",
            "offer": "WindowsServer",
            "sku": "2019-Datacenter",
            "version": "latest"
          },
          "osDisk": {
            "createOption": "FromImage"
          }
        },
        "networkProfile": {
          "networkInterfaces": [
            {
              "id": "[resourceId('Microsoft.Network/networkInterfaces', variables('nicName'))]"
            }
          ]
        }
      }
    }
  ],
  "outputs": {
    "adminUsername": {
      "type": "string",
      "value": "[parameters('adminUsername')]"
    },
    "publicIP": {
      "type": "string",
      "value": "[reference(variables('publicIPName')).ipAddress]"
    }
  }
}

Parameters

Define parameters to make your template reusable and environment‑agnostic.

Name	Type	Default	Description
vmName	string	myVM	Name of the virtual machine.
adminUsername	string	azureuser	Admin user for the VM.
adminPassword	secureString		Secure admin password.
vmSize	string	Standard_DS1_v2	Size of the VM.

Best Practices

Store secret values in Azure Key Vault and reference them via reference().
Use dependsOn only when necessary; Azure resolves most dependencies automatically.
Leverage linked templates for modular deployments.
Version your templates and use contentVersion for tracking changes.