Azure ARM template vs Azure Bicep – What Are The Differences?

Learn about the differences between Azure Arm Template and the Azure Bicep Template

In late 2020, Microsoft announced its project Bicep and released an early alpha version. Bicep was created to deal with the challenges faced by users for Azure Resource Management and writing code for infrastructure. Bicep was created as a transparent layer over Azure ARM to enhance its functionality and simplify the user experience. Read more below about the key differences between Azure ARM and Azure Bicep.

What Is Azure Bicep?

  • Azure Bicep is a Domain Specific Language (DSL) for declaring and deploying Azure resources without specifying each resource separately. It was created to simplify the process of writing code. It has a clearer and simpler syntax than Azure ARM. It offers superior support for modularity and reusing code.

Azure Bicep can be thought of as a revised version of Azure ARM. It is not an entirely new language but was made after modifying Azure ARM. The current version 0.3 is considered to be the latest release and stable for use. Any workload from Azure ARM can be done efficiently in Azure Bicep.

Core Differences Between Azure Bicep and Azure ARM Template

  • There are not many differences between Azure Bicep and Azure ARM. Since Azure Bicep is a transparent abstraction over ARM, essentially everything that can be done in ARM can be replicated in Bicep. Azure ARM resources such as API versions, properties, and types are valid for use in Bicep. If a particular type resource is not available in Bicep, it will still deploy it after sending a warning message.

Azure Bicep’s code is transpiled into a JSON file standard to Azure ARM. This functionality treats Azure ARM as an intermediary language. While the language syntax for Azure Bicep is different than Azure ARM, the core functionalities of Azure ARM templates remain the same. The resource declarations and template functions are also the same.

Main Features of Azure Bicep

  • Azure Bicep is an open-source language and is available to all Azure users. It offers the same functionality as Azure ARM template but is easier to use and deploy. Several tools are available that aim to ease user migration from Azure ARM to Azure Bicep. Azure Bicep offers more than 250 resource types. Thus its ability to perform tasks is matched to that of Azure ARM template. Azure Bicep also includes a CLI to compile and decompile operations.

Terraform, Farmer, and Pulumi are some of the more popular alternatives for Azure Bicep. The core difference between using these alternatives and Azure Bicep is that Azure Bicep transpiles into JSON templates that are native to Azure ARM and Azure. The runtime remains unchanged, and the difficulty of working with JSON is minimized. Microsoft has a dedicated team for Terraform to enhance the user experience; however, analysts believe that Azure Bicep will overtake all the other alternatives due to its compatibility with Azure and Azure ARM template.

Known Limitations of Azure Bicep

  • Based on user experience, there are a few known limitations of Azure Bicep. The first limitation is the lack of support for single-line objects and arrays. The second limitation is Bicep’s code’s sensitivity to newline.

Bicep also lacks support for apiProfile, which is used to map an individual apiProfile to set apiVersion for a particular resource type.

Is Azure Bicep Difficult To Learn?

  • azure arm templateBased on user experience reviews online, Azure Bicep is not at all difficult to learn and master. The resource declarations, template functions, template modularity, outputs, and properties are made in the same way as for Azure ARM template. Azure Bicep’s code is simpler, concise, and easier to understand.

Using Visual Studio Code with the extension for Bicep provides an interactive code editor. This editor offers IntelliSense, syntax validation, and rich type-safety features to help users write the perfect code every time. Thus, the time to fix syntax-related bugs is minimized.

  • If you are unsure about migrating to Azure Bicep, then why not contact Henson Group today? We have been one of the best-managed service providers (MSP) for Microsoft Azure since 2002. We have a strong presence and years of experience working in diverse markets like the US, Europe, and Asia. Call us today for your free Azure assessment and let our experts take care of your Azure needs.