Compare Azure Resource Manager and Terraform State
Your team knows the benefits of infrastructure as code and the different approaches that are available. Your company is growing at a rapid pace and your team will deploy a significant number of resources to Azure. Declarative infrastructure as code is the right approach to resource provisioning. The team doesn't want to maintain scripts that list every deployment step. Before beginning the process of building your first template, you need to understand how Azure Terraform and Azure Resource Manager works. Investigating the types of templates that are available to use with Azure will help you determine the next steps in your infrastructure-as-code strategy.
This unit covers the difference between Azure Resource Manager and Terraform state.
Azure Resource Manager vs Terraform state
Azure Resource Manager
Azure Resource Manager is the service that's used to deploy and manage resources in Azure with Bicep or ARM templates. You can use Resource Manager to create, update, and delete resources in your Azure subscription. It expects a declarative template that it translates into a set of idempotent commands to create or update your resources.
Terraform State
Terraform state is a json based representation of the resources you're managing with Terraform. Terraform is an agnostic tool that can support anything with an API end point, therefore it requires an agnostic method to manage the lifecycle of resources under management. The state file essentially maps the resource declaration in your template to the ID of the resource in the target environment, in our case Azure.
Comparison of Azure Resource Manager and Terraform State
| Item | Azure Resource Manager | Terraform State |
|---|---|---|
| State file management | Not required, state is stored in Microsoft Azure | State file must be stored and secured |
| Support for other cloud providers and APIs | Only works with Microsoft Azure and Microsoft Entra ID | Works with any cloud or API that has a provider built for it |
| Lifecycle (create, update, delete) | Deployment stacks now allow managing the full life cycle | Terraform is able to manage the full lifecycle |
| Drift detection / plan | What If allows checking for updates | Terraform plan enables drift detection and planning |