What is Azure Resource Manager? A Comprehensive Overview

What is Azure Resource Manager?

Azure resource manager is a service for deploying and managing resources using an infrastructure as a code paradigm. It allows you to modify, provision, and remove resources through different features.

Some of the standard Azure ARM terms that you must be familiar with when using ARM are as follows:

1. Resource:

It is an asset that can be managed. Assets include virtual networks, machines, web applications, databases, and storage accounts. Resources might also include subscriptions, management groups, resource groups, or tags.

2. Resource Group:

A resource group is a container that groups together relatable resources. In Azure, resource groups allow you to manage different resources as a whole.

3. Resource Provider:

A resource provider is a set of REST operations allowing a specific Azure service functionality. It is the only service in Azure where you can create resources. Examples include Microsoft Compute for virtual machines and Microsoft Storage for storage accounts.

4. Resource Manager Template:

A JSON file that defines the infrastructure and configuration for your project.  A file defines how resources must be deployed to subscriptions, groups, or tenants.

5. Declarative Syntax:

Declarative syntax is utilized for resource management templates. It allows users to define how resources must be handled without knowing programming commands.

What is Consistent Management Layer?

When you forward a request via any Azure tools, APIs, or SDKs and the resource manager receives it, it authorizes and authenticates the request before sending it to the Azure service. As each request is handled via the same API, you see constant capabilities and results in all the multiple tools.

This consistent way in which Azure handles requests sent through any of its tools, APIs, or SDKs is referred to as Consistent Management Layer. 

Also Read: Microsoft Azure Tutorial for Beginners

The Benefits of Using Resource Manager

Azure resource manager offers multiple advantages in terms of deployment and resource management. These benefits are as follows:

1. Security

ARM lets you use various security and safety features with your resources, such as OAuth authentication and role-based access controls. It offers granular control over resources and lets you restrict who can modify specific workloads. This also includes the ability to lock resources against deletion or modification.

Moreover, all events within ARM are logged with event users and changes. This assists audit management as required and ensures that your environment management aligns with compliance standards.

2. Centralized Management

ARM lets you manage resources from centralized dashboards. It also allows you to integrate multiple Azure resources, including services from the Microsoft Azure marketplace and third-party applications.

This centralization also ensures that resources are managed consistently. It also enhances visibility into your resource configuration, allowing consistent management across different tools.

3. Templates

ARM templates let you deploy and define multiple Azure resources that you require to be consistent and clear. They let you define resource details such as locations, names, security settings, availability zones, and networks. After defining, you can utilize Azure templates to deploy identical resources repeatedly, as required for distributed applications, development, or testing.

ARM templates can be customized, modified, or built through Visual Studio, Visual Studio Code, or Azure Portal. You can even completely automate ARM template deployment, eliminating the need for manual configurations. In addition, if you use third-party tools, you can readily use ARM templates on Azure marketplace solutions.

What is an Azure Resource Manager Template?

Azure resource manager templates or JSON files define your project's configuration and infrastructure. Templates utilize declarative syntax, so you can specify what you want to deploy without writing multiple commands that define how to deploy it. Templates also specify the resources to be deployed and their properties. 

The template is to be used for deployment only after it gets validated by the resource manager. This reduces the occurrence of deployment failure midway.

The template consists of the following parts:

• Parameters: Parameters allow you to use a single template in multiple environments during deployment.
• User-defined functions: It will enable you to define customized elements for template simplification.
• Variables: These values can be reused in multiple templates and utilize values from parameters.
• Resources: These specify the Azure resources that are to be deployed.
• Outputs: These values can be returned after deployment and are often used for sharing important information or for subsequent deployments.

Recommended Read: Azure Cloud Services and Its Importance

ARM Template Best Practices

While crafting ARM templates, you must consider multiple best practices. These practices make management efficient and ensure that you can easily determine your resources.

1. Template Limits

Azure enforces certain size limits on ARM templates: a maximum template size of 4MB and a maximum parameter file size of 64KB. These limits include all nested resources, variables, definitions, and parameters. Exceeding these limits may cause deployment failures.

In addition, you must also consider some hard limits for templates. These restrict you:

• 64 output values
• 24,576 characters in a template expression
• 256 variables
• 800 resources
• 256 parameters 

2. Resource Groups

Each resource group you craft stores meta-data about the resources it contains. This meta-data gets stored in a similar location as your group. This means that if a region becomes inaccessible, you will be able to manage the resources in that group once access is restored.

If you want to craft a resource group failover, ensure to store a copy of your meta-data in the failover region. This allows you to retain control even when your original group is inaccessible.

3. Consider YAML

JSON is the format for ARM templates. This format is suitable for simple templates, but as the deployment and resource number complexities rise, these templates might lose their human readability.

Even though you cannot edit this format, you can create your templates in YAML and convert them to JSON using a conversion tool before deployment. YAML increases the readability of your template and lets you comment on why and how you are defining resources. It would be extremely helpful if different team members could work to define templates.

4. Avoid Linking Templates if not Necessary

Linked templates are a feature that allows you to diversify your resources into specific templates. Later, these templates are linked together and entitled to one deployment source.

This linking is amazing, except that it needs templates to be publicly accessible, or your deployment pipeline must be accessible. You can offer this access later with the SAS token, but it still brings some vulnerability to your system.

Moreover, if you use link templates, you can use parameter objects or URIs. You cannot combine formats, restricting your ability to manage crucial information within the template.

Rather than working around search issues, you must use standard templates. You can even use your pipelines for deployment control and ensure that dependent templates are deployed together. This lets you achieve the same results as linked templates with better security.

Azure Classic vs Resource Manager

The Azure public cloud offers support to two deployment models:

1. Classic Mode

Each resource in Azure classic mode or Azure Service Management (ASM) is a separate management unit. Azure resources are crafted in a cloud container. However, the container cannot be managed because, as a whole, every resource is managed individually. Resource grouping is not allowed in the classic mode, which makes Azure resources management less convenient.

2. Azure Resource Manager

ARM is the latest way to deploy Azure resources through resource groups, which allows you to manage different resources together. When you interact with ARM resource groups through the Azure Portal or Azure PowerShell, you use the ARM API behind the scenes.

Both ARM and classic resources can be availed in Azure's new portal. However, you only use classic resources when using the classic portal.

Conclusion

The Azure resource manager is a management service that lets you manage layers that help you update, create, and remove resources in your Azure account. To understand and experience more about the Azure Resource Manager (ARM), connect with Simplilearn and enroll in the Designing Microsoft Azure Infrastructure Solutions (AZ-305) Training Course today.

FAQs

Q1. What language does Azure Resource Manager use?

Bicep is the language used in Azure Resource Manager.

Q2. How does Azure Resource Manager improve resource management?

ARM supports automation and template-driven deployment. This helps define infrastructures as code that can be tested, deployed, and version-controlled as a part of your pipelines.

Q3. How does role-based access control (RBAC) work with Azure Resource Manager?

It helps manage who gets access to Azure resources, how they use those resources, and the areas they access them.

Q4. What is the difference between Azure Resource Manager and RBAC?

ARM is a management Azure service that lets you manage layers that help you update, create and remove resources in your Azure account. However, RBAC helps manage who gets access to Azure resources, how they use those resources, and the areas they get access to.