Setting Up Infracost with Terragrunt Repos

Oct 13, 2025 by talynt.org 34 views

$Setting Up Infracost with Terragrunt Repos$

Infracost GitHub App with Terragrunt Repos: A Step-by-Step Guide

Infracost is a popular tool used for estimating the cost of cloud infrastructure. It integrates seamlessly with GitHub, allowing users to estimate costs directly from their pull requests. However, when using Terragrunt, a popular tool for managing Terraform configurations, users may encounter issues with Infracost commenting on pull requests. In this article, we will explore the steps to set up Infracost with Terragrunt repos and troubleshoot common issues.

Setting Up Infracost with Terragrunt Repos

To set up Infracost with Terragrunt repos, follow these steps:

Step 1: Create an Infracost GitHub App

Log in to your GitHub account and navigate to the GitHub Apps page.
Click on the "New GitHub App" button.
Fill in the required information, including the app name, description, and homepage URL.
Under "Webhooks", select "Pull requests" and "Issues" as the events to trigger the app.
Click on the "Save" button to create the app.

Step 2: Configure Infracost Cloud Portal

Log in to the Infracost Cloud Portal and navigate to the "Settings" page.
Click on the "GitHub Apps" tab.
Select the GitHub app you created in Step 1.
Under "Repository settings", select the repository you want to integrate with Infracost.
Click on the "Save" button to save the changes.

Step 3: Configure Terragrunt

In your Terragrunt configuration file (usually terragrunt.hcl), add the following configuration:

terraform {
  source = "your-terraform-module-url"
}

inputs = {
  // your input variables
}

Make sure your Terragrunt configuration file is in the root of your repository.

Step 4: Verify Infracost Configuration

Log in to the Infracost Cloud Portal and navigate to the "Settings" page.
Click on the "GitHub Apps" tab.
Select the GitHub app you created in Step 1.
Under "Repository settings", verify that the repository you want to integrate with Infracost is selected.
Click on the "Save" button to save the changes.

Issue 1: Infracost does not comment on PRs

If Infracost does not comment on PRs, check the following:

Make sure the GitHub app is enabled and configured correctly.
Verify that the repository is selected in the Infracost Cloud Portal.
Check the Terragrunt configuration file for any errors.
Try running infracost estimate manually in your repository to see if it works.

Issue 2: Check is skipped after trying for 20 minutes

If the check is skipped after trying for 20 minutes, check the following:

Make sure the GitHub app is enabled and configured correctly.
Verify that the repository is selected in the Infracost Cloud Portal.
Check the Terragrunt configuration file for any errors.
Try running infracost estimate manually in your repository to see if it works.

Additional Configurations Required for Terragrunt

Terragrunt requires additional configurations to detect .hcl files. To add these configurations, follow these steps:

Log in to the Infracost Cloud Portal and navigate to the "Settings" page.
Click on the "GitHub Apps" tab.
Select the GitHub app you created in Step 1.
Under "Repository settings", click on the "Add configuration" button.
Select "Terraform" as the configuration type.
Add the following configuration:

{
  "terraform": {
    "source": "your-terraform-module-url"
  }
}

Click on the "Save" button to save the changes.

In this article, we explored the steps to set up Infracost with Terragrunt repos and troubleshoot common issues. We also discussed the additional configurations required for Terragrunt to detect .hcl files. By following these steps, you should be able to successfully integrate Infracost with your Terragrunt repos and estimate costs directly from your pull requests.
Infracost GitHub App with Terragrunt Repos: Q&A

In our previous article, we explored the steps to set up Infracost with Terragrunt repos and troubleshoot common issues. However, we understand that you may still have questions about the process. In this article, we will address some of the most frequently asked questions about Infracost GitHub app with Terragrunt repos.

Q: What is Infracost, and how does it work with Terragrunt?

A: Infracost is a tool that estimates the cost of cloud infrastructure. It integrates with GitHub to estimate costs directly from pull requests. Terragrunt is a tool that manages Terraform configurations. When you use Infracost with Terragrunt, it estimates the cost of your Terraform configurations and provides a detailed breakdown of the costs.

Q: How do I set up Infracost with Terragrunt repos?

A: To set up Infracost with Terragrunt repos, follow these steps:

Create an Infracost GitHub app.
Configure the Infracost Cloud Portal.
Configure Terragrunt.
Verify Infracost configuration.

Q: What are the common issues that I may encounter when setting up Infracost with Terragrunt repos?

A: Some common issues that you may encounter when setting up Infracost with Terragrunt repos include:

Infracost does not comment on PRs.
Check is skipped after trying for 20 minutes.

Q: How do I troubleshoot common issues?

A: To troubleshoot common issues, follow these steps:

Verify that the GitHub app is enabled and configured correctly.
Verify that the repository is selected in the Infracost Cloud Portal.
Check the Terragrunt configuration file for any errors.
Try running infracost estimate manually in your repository to see if it works.

Q: Do I need to add additional configurations for Terragrunt to detect `.hcl` files?

A: Yes, you need to add additional configurations for Terragrunt to detect .hcl files. To add these configurations, follow these steps:

Log in to the Infracost Cloud Portal and navigate to the "Settings" page.
Click on the "GitHub Apps" tab.
Select the GitHub app you created in Step 1.
Under "Repository settings", click on the "Add configuration" button.
Select "Terraform" as the configuration type.
Add the following configuration:

{
  "terraform": {
    "source": "your-terraform-module-url"
  }
}

Click on the "Save" button to save the changes.

Q: How do I estimate costs with Infracost and Terragrunt?

A: To estimate costs with Infracost and Terragrunt, follow these steps:

Run infracost estimate in your repository to estimate costs.
Infracost will provide a detailed breakdown of the costs.
You can use this information to optimize your infrastructure costs.

Q: Can I use Infracost with other tools like Terraform and AWS CloudFormation?

A: Yes, you can use Infracost with other tools like Terraform and AWS CloudFormation. Infracost supports a wide range of cloud providers and infrastructure as code tools.

In this article, we addressed some of the most frequently asked questions about Infracost GitHub app with Terragrunt repos. We hope that this information has been helpful in setting up and troubleshooting Infracost with Terragrunt repos. If you have any further questions, please don't hesitate to contact us.