Azure Arm Templates | Azure Developer Tools

Introduction

Azure Resource Manager (ARM) templates are JSON files that define the infrastructure and configuration for your Azure solution. Using ARM templates, you can declaratively specify the resources that need to be deployed for your application. This tutorial provides a comprehensive guide to understanding and using ARM templates to manage resources in Azure.

Benefits of Using ARM Templates

ARM templates offer several benefits, including:

Declarative Syntax: Define the desired state and let Azure handle the deployment.
Repeatable Deployments: Consistently deploy the same resources multiple times.
Infrastructure as Code: Manage infrastructure using version control systems.
Modular and Reusable: Break down templates into smaller, reusable components.

Structure of an ARM Template

An ARM template consists of the following sections:

Schema: The location of the JSON schema that defines the structure of the template.
Content Version: The version of the template (e.g., "1.0.0.0").
Parameters: Values that you can pass during deployment to customize resource properties.
Variables: Values that are computed from parameters and used within the template.
Resources: The Azure resources to be deployed or updated.
Outputs: Values that are returned after the deployment is executed.

Creating a Simple ARM Template

Let's create a simple ARM template to deploy a storage account in Azure.

{
    "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
        "storageAccountName": {
            "type": "string",
            "minLength": 3,
            "maxLength": 24
        },
        "location": {
            "type": "string",
            "defaultValue": "West US",
            "allowedValues": [
                "East US",
                "West US",
                "West Europe",
                "Southeast Asia"
            ]
        }
    },
    "resources": [
        {
            "type": "Microsoft.Storage/storageAccounts",
            "apiVersion": "2019-04-01",
            "name": "[parameters('storageAccountName')]",
            "location": "[parameters('location')]",
            "sku": {
                "name": "Standard_LRS"
            },
            "kind": "StorageV2",
            "properties": {}
        }
    ]
}

Deploying an ARM Template

There are several ways to deploy an ARM template, including using the Azure portal, Azure CLI, and PowerShell. Here, we'll use Azure CLI to deploy our template.

Using Azure CLI

First, save your template as template.json. Then, use the following commands:

# Authenticate with Azure
az login

# Create a resource group
az group create --name myResourceGroup --location "West US"

# Deploy the template
az deployment group create --resource-group myResourceGroup --template-file template.json --parameters storageAccountName=myuniquestorageacct

Using Azure PowerShell

Alternatively, you can use Azure PowerShell to deploy your template:

# Authenticate with Azure
Connect-AzAccount

# Create a resource group
New-AzResourceGroup -Name myResourceGroup -Location "West US"

# Deploy the template
New-AzResourceGroupDeployment -ResourceGroupName myResourceGroup -TemplateFile template.json -storageAccountName myuniquestorageacct

Advanced Template Features

ARM templates support advanced features such as:

Nested Templates: Break down large templates into smaller, manageable files.
Linked Templates: Reference other templates to create complex deployments.
Custom Functions: Define custom logic within your templates using user-defined functions.
Conditional Deployments: Deploy resources conditionally based on parameters or variables.

Conclusion

Azure Resource Manager templates offer a powerful way to manage your Azure resources declaratively. By following this tutorial, you should now have a good understanding of how to create, structure, and deploy ARM templates. With practice, you can leverage ARM templates to automate and streamline your Azure deployments.

Azure Resource Manager Templates Tutorial