How to Conditionally Add Objects to Arrays in Terraform

Learn how to conditionally add objects to arrays in Terraform using dynamic construction techniques while ensuring clarity and flexibility in your infrastructure code.
---

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Conditionally add object to array

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Conditionally Add Objects to Arrays in Terraform

Adding objects to arrays in Terraform can be a tricky task, especially when you need to conditionally include elements based on certain criteria. In this guide, we will explore how to dynamically construct the elements of the records module parameter in Terraform to achieve this requirement. Let's dive into the problem and the solution.

Understanding the Problem

You need a solution that allows you to add a mandatory DNS record to your Route53 configuration while also conditionally adding an optional wildcard record if a certain condition is met.

Solution Breakdown

To achieve this, we will use the concat function in Terraform. This approach will allow us to combine a constant record with a conditional array for the wildcard record based on your specified logic. Here’s how you can structure your records parameter effectively.

Step 1: Mandatory Record Definition

First, we will define the mandatory DNS record. This is the record that is always included in the array, irrespective of any conditions.

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Conditional Record Definition

Next, we'll create a conditional statement to decide whether to include the wildcard record. If the condition is satisfied, we will provide the necessary details; otherwise, we will return an empty list.

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Combining the Records

Finally, we will use the concat function to combine the mandatory record with the conditional array. This allows for a clean and dynamic addition of elements.

[[See Video to Reveal this Text or Code Snippet]]

Final Implementation

Here’s how your complete module code snippet would look with the modifications:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

By utilizing the concat function alongside conditional expressions, you've successfully structured your Terraform configuration to conditionally add an object to an array based on specified criteria. This not only keeps your code clean but also adds flexibility to your infrastructure as code.

Now you can efficiently manage your DNS records in Route53, adapting to varying conditions with ease. Happy coding!