Azure Resource Manager Template: A Comprehensive Guide to Deployment and Management

Azure Resource Manager (ARM) templates are a powerful tool for deploying and managing Azure resources. They allow you to define and deploy Azure resources consistently and reliably.

ARM templates are written in JSON and can be used to deploy a wide range of Azure resources, including virtual machines, storage accounts, and networks. These templates can be easily version-controlled and shared with others.

The benefits of using ARM templates include improved consistency, reduced deployment time, and enhanced collaboration. By using ARM templates, you can ensure that your Azure resources are deployed consistently and in the correct order.

ARM templates can be deployed using the Azure portal, Azure CLI, or Azure PowerShell. The deployment process involves uploading the template to Azure and providing the necessary parameters.

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Azure is a powerful cloud computing platform that allows you to organize resources in a consistent and modular way.

ARM provides a consistent way to create, deploy, and manage Azure resources, making it easier to manage your infrastructure.

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With Azure, you can define and deploy resources as a single logical unit called a resource group, which can contain various resources such as virtual machines, storage accounts, and network interfaces.

ARM enables you to automate the deployment and management of your infrastructure, saving time and reducing errors.

By using ARM, you can tag your resources, making it easier to organize, track, and manage them.

Here are some key benefits of using ARM:

ARM templates are written in JSON (JavaScript Object Notation), a human-readable and easy-to-write format.

ARM templates describe the desired state of resources in a declarative manner, allowing you to specify what resources should exist and their configurations.

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Parameters are a crucial part of Azure Resource Manager (ARM) templates, allowing users to input values during deployment. This makes templates more flexible and reusable.

In an ARM template, parameters are defined in the parameters section. You can specify up to 256 parameters in a template. To reduce the number of parameters, you can use objects that contain multiple properties.

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The available properties for a parameter are:

You can also specify additional properties such as minValue, maxValue, minLength, maxLength, prefixItems, items, properties, additionalProperties, discriminator, nullable, and description. These properties are optional and provide more control over the parameter's behavior.

For example, you can define a parameter for a username and password for a Virtual Machine, specifying the type and default value.

In some cases, specifying parameters in line with the PowerShell deployment command can be time-consuming, especially when there are many parameters. In such cases, you can specify the value in a parameter file, which can be created in a file named storageAccount.parameters.json.

Resources play a crucial role in Azure deployments. All the azure resources are defined here which makes the deployment.

To create a resource, you need to set up the type, name, location, version, and properties of the resource that needs to be deployed. We can also use the variables and parameters here that are defined in the ‘variables’ section.

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Microsoft Learn has modules to help you learn more about ARM templates, including how to develop and deploy more complex environments. Examine their learning path for modules that go deeper into developing ARM templates.

The Azure Portal is the place where you create resources. In the Azure Portal, you will see various options listed to create a resource, such as Windows, Ubuntu, Web App, SQL Database, etc.

ARM templates are written in JSON (JavaScript Object Notation) and are used to define and deploy resources into the Microsoft Azure cloud platform. This declarative approach allows you to specify what resources should exist and their configurations.

To create a resource group, you can use the New-AzResourceGroup command, which requires giving the resource group a name and an Azure region.

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You can create a template from scratch using the Azure Portal's Template Editor. To do this, click on the 'Build your template in the editor' option after clicking the 'Create' button.

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The Template Editor will open, displaying a simple format of the ARM Template. This is where you can write and add your code in the editor. You can also use the highlighted menu at the top to add a resource, use a quickstart template, load your template file, or download the created template.

ARM templates are written in JSON and are used to define and deploy resources into the Microsoft Azure cloud platform. They describe the desired state of resources in a declarative manner, allowing you to specify what resources should exist and their configurations.

To add a resource, you can use the 'Add a resource' option in the Template Editor. This will give you a list of available resource types to choose from, including Azure Storage, Azure Virtual Network, and more.

Here are some common resource types you can add to your ARM template:

The ARM template file format is a crucial aspect of Azure Resource Manager. It typically has a file extension of .json.

The top-level structure of an ARM template includes various properties, each serving a specific purpose. The schema declaration property is first up and specifies the version of the ARM template schema that the template uses.

The schema declaration property is a critical part of the template, as it determines the version of the template language used. This is essential for ensuring compatibility with Azure services.

The contentVersion property indicates the version of the template. This is typically a string, used for versioning the template.

You can specify the schema type, such as the location of the JSON file and the version of the template language. Some common schema types include:

Comments in ARM templates are written using /* */ for block comments and // for inline comments. This helps make your templates more readable and maintainable.

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You can deploy an ARM template using PowerShell with a script like deploy-vnet.ps1, or using Azure CLI.

ARM templates can be deployed in complete mode, which removes any resources in the resource group not defined in the template.

In complete mode, ARM deploys and updates all resources defined in your template, and it removes any resources in the resource group that are not defined in the template.

After creating and deploying an ARM template, you're ready to return to the Azure Portal to verify the deployment.

You can now return to the Azure Portal to check the status of your deployment. The portal will show you the resource group deployment progress.

To deploy the ARM template, you'll need to run the New-AzResourceGroupDeployment command in PowerShell. This command requires the resource group to deploy to and the path to the template file.

The name of the storage account must be globally unique across Azure, with all lowercase numbers and letters.

To deploy ARM templates using PowerShell, you'll need PowerShell 5.1 or later, specifically version 7.1.3 was used in this tutorial.

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You'll also need the PowerShell module for Azure, version 6.0.0 was used here.

An Azure administrator account with resource creation permissions, such as Owner or Contributor, is required.

To deploy an ARM template, you can use a script like deploy-vnet.ps1, or alternatively, you can use Azure CLI.

In incremental mode, Resource Manager ignores resources in the resource group that isn't specified in the template.

All properties are reapplied when redeploying an existing resource in incremental mode.

Complete Mode is a deployment mode in Azure Resource Manager (ARM) that ensures the resource group exactly matches the state defined in the template.

By default, deployments operate in incremental mode, but you need to specify --mode Complete if you want to use complete mode.

In complete mode, ARM deploys and updates all resources defined in your template, and it removes any resources in the resource group that are not defined in the template.

This mode is more aggressive and can lead to the deletion of existing resources not defined in the template.

Resource Manager deletes resources that exist in the resource group but are not specified in the template when in complete mode.

If your template contains a resource that isn’t deployed because the condition evaluates to false, the outcome is determined by the REST API version used to deploy the template.

Incremental mode is the default deployment mode for Azure Resource Manager (ARM), and it's suitable for most scenarios, especially during regular deployments or updates.

In incremental mode, ARM deploys and updates only the resources defined in your template that have changed or are new.

Existing resources in the resource group are left unchanged, unless you specify new properties in the template, in which case ARM updates the resource with the new value.

If you redeploy an existing resource in incremental mode, all properties are reapplied, and properties not specified in the template are reverted to their default values.

Resource Manager interprets the deployment as overwriting those values, so it's essential to specify all the necessary properties in the template.

ARM deployment modes support two primary modes: incremental and complete, with incremental being the default mode.

Template management is a crucial aspect of Azure Resource Manager (ARM) templates.

ARM templates are version-controlled, allowing you to track changes and collaborate with others.

You can manage templates using Azure DevOps or GitHub, which support template versioning and branching.

This makes it easier to manage and deploy complex infrastructure configurations.

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Outputs are the final result of a template run, showing the desired outcome when a template is successfully deployed. They can be thought of as the end product of a template's execution.

You can specify up to 64 outputs in a template, which is a limitation to keep in mind when designing your templates. Typically, outputs are used to return values from resources that were deployed.

The structure of an output definition is as follows:

In Bicep, the concept of outputs is similar, allowing you to expose information from deployed resources. These outputs can be used for reference or passed as parameters to other templates.

You can use outputs to return values from resources that were deployed, such as the hostname with a value fetched from the public IP address name. This can be useful for referencing or passing the values to other templates.

To remove resources from a resource group, consider using ARM's complete mode. In complete mode, ARM removes any resources in the resource group that are not defined in the template.

ARM templates can be used to define the resources to be removed. For example, a simple ARM template can be created with a single parameter called StorageAccountName to set the storage account name.

Complete mode is typically used when you want to ensure that the resource group exactly matches the state defined in the template. This can lead to the deletion of existing resources not defined in the template.

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There are two primary modes for deploying and managing resources with Azure Resource Manager (ARM): incremental and complete.

Incremental mode is suitable for most scenarios, especially during regular deployments or updates where you want to add, modify, or remove specific resources without affecting the entire resource group.

In incremental mode, ARM deploys and updates only the resources defined in your template that have changed or are new.

It leaves existing resources in the resource group unchanged.

ARM attempts to create all template resources in both incremental and complete modes. If the resource already exists and matches the template resource, the Azure resource is left unchanged.

If you change the value of one or more properties in a resource, Azure updates the resource with the new value.

You can use complete mode with caution, especially with copy loops, as it can lead to the deletion of existing resources not defined in the template.

In complete mode, ARM deploys and updates all resources defined in your template, and it removes any resources in the resource group that are not defined in the template.

You only need to specify --mode Complete if you explicitly want to use complete mode, as deployments operate in incremental mode by default.

Linked templates are a great way to break down complex templates into manageable components. In fact, Azure Resource Manager supports the concept of linking templates, which allows you to create a main template that links to other templates and parameters files via URI.

To make the most of linked templates, your URI must be publicly accessible by the Azure Resource Manager. This means you can't use a private link, and you'll need to make your templates accessible via a URL like http://www.contoso.com/AzureTemplates/newStorageAccount.json.

Breaking down your templates into smaller, linked components can make them much easier to work with and deploy. And if you're just getting started with Azure Resource Manager, you may want to check out the Azure Quickstart Templates for some inspiration and guidance.

Here are some next steps to consider:

Comments in ARM templates can be a lifesaver for understanding complex deployments. You can use either // or /* ... */ for inline comments.

In Visual Studio Code, save your parameter files with comments as JSON with comments (JSONC) file type to avoid getting an error message saying "Comments not permitted in JSON".

Azure CLI users should upgrade to version 2.3.0 or later and specify the --handle-extended-json-format switch to deploy templates with comments.

The Azure Resource Manager Tools extension in Visual Studio Code can automatically detect an ARM template and change the language mode. This allows you to use inline comments, which are no longer marked as invalid.

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Azure Blueprints are a great tool for defining and deploying a set of resource templates and other artifacts as a package. They go beyond Infrastructure as Code (IaC) and include policy definitions, resource groups, role-based access control (RBAC), and more.

Azure Blueprints provide a higher-level, more abstract view of an entire environment, aiming to provide a more comprehensive governance framework. This is in contrast to ARM templates, which offer fine-grained control over individual resources.

Azure Blueprints are a more comprehensive solution for managing complex environments, making them a great choice for large-scale deployments. They can help you establish a standardized approach to infrastructure management.