How to Check If a Resource Exists in the ARM Template?


When working with Azure Resource Manager (ARM) templates, you may need to check if a specific resource exists before performing actions on it. This can be critical to avoid errors in deployment or update operations. In this blog post, we’ll explore how to check if a resource exists within an ARM template using conditional statements.

Concepts Used

ARM Template

An Azure Resource Manager (ARM) template is a JSON file that defines the resources you need to deploy for your solution. It allows you to declaratively define your Azure infrastructure.

Conditional Functions

Azure ARM Templates offer conditional functions like if(), equals(), and more, that allow you to evaluate expressions based on certain conditions.

Step-by-Step Guide to Check If a Resource Exists

Step 1: Define the Resource Identifier

You need to have the specific identifier of the resource you want to check. It could be a combination of resource group, name, type, etc.

Step 2: Use the reference Function (Optional)

The reference function can be used to get a reference to a full resource object if you know its ID. You may use it with the conditional if() function to check if the resource exists.


Step 3: Utilize the exists Function

The exists function returns a Boolean value that indicates whether the resource exists.


Step 4: Implement Conditional Logic

You can use the result from the exists function to conditionally create or modify resources within your ARM template.



Checking if a resource exists in an ARM template is a valuable technique to ensure robust and error-free deployment scripts. By leveraging Azure’s built-in functions like exists, you can easily create conditional logic in your ARM templates that adapts to the current state of your Azure environment. This enhances the flexibility of your templates, allowing them to be reused in various scenarios and stages of the development lifecycle.