Decoding Azure Infrastructure: Azure Bicep and ARM Templates

Azure Bicep vs ARM Templates

In the world of Azure infrastructure as code (IaC), two major players are Azure Resource Manager (ARM) templates and Azure Bicep. Both are powerful tools for managing Azure resources, but they have significant differences. This article will compare these two technologies and highlight the advantages of Azure Bicep over ARM templates.

What are ARM Templates?

Azure Resource Manager (ARM) templates are JSON files that define the resources needed to deploy an application in Azure. They provide a declarative way to define deployment configurations, allowing you to specify the resources to deploy and their properties.

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {},
  "variables": {},
  "resources": [],
  "outputs": {}
}

What is Azure Bicep?

Azure Bicep is a domain-specific language (DSL) for deploying Azure resources declaratively. It’s a transparent abstraction over ARM and ARM templates, aiming to drastically simplify the authoring experience with a cleaner syntax and better support for modularity and code reuse.

param storageAccountName string = 'mystorageaccount'

resource storageAccount 'Microsoft.Storage/storageAccounts@2021-04-01' = {
  name: storageAccountName
  location: resourceGroup().location
  sku: {
    name: 'Standard_LRS'
  }
  kind: 'StorageV2'
}

Azure Bicep vs ARM Templates

Syntax: While ARM templates use JSON syntax, Azure Bicep uses a cleaner and more intuitive syntax. This makes Bicep files easier to read and write.
Modularity: Azure Bicep supports modularity, which allows you to break down your infrastructure into smaller, reusable components. This feature promotes code reuse and makes managing your infrastructure more manageable.
Tooling: Azure Bicep is fully integrated with Visual Studio Code, providing features like autocompletion, code navigation, and live linting. It also offers seamless integration with Azure CLI and Azure PowerShell.
Transparency: Azure Bicep is a transparent abstraction over ARM and ARM templates, meaning anything that can be done in an ARM Template can be done in Bicep.

Conclusion

While ARM templates have been the standard for Azure IaC for many years, Azure Bicep offers several advantages that make it a compelling alternative. Its simplified syntax, improved modularity, and better tooling make it an excellent choice for anyone looking to adopt IaC practices in Azure.

In the next article, we will dive deeper into Azure Bicep and learn how to get started with it. Stay tuned!