> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Sourcing a Module From the Terraform Registry

> Learn to source and manage Terraform modules using Terragrunt for efficient infrastructure as code practices.

Leverage the Terraform Registry to discover, share, and reuse community-maintained modules. When you integrate Terragrunt, you can reference these modules directly using the `tfr://` protocol.

## 1. Referencing a Module in Terragrunt

In your `terragrunt.hcl` file, set the `source` attribute to point at a Registry module:

```hcl theme={null}
# terragrunt.hcl
terraform {
  source = "tfr://<namespace>/<module_name>/<provider>"
}
```

| Element      | Description                                  | Example               |
| ------------ | -------------------------------------------- | --------------------- |
| namespace    | Author or organization publishing the module | terraform-aws-modules |
| module\_name | Identifier for the module                    | vpc                   |
| provider     | Cloud provider name                          | aws                   |

Example:

```hcl theme={null}
terraform {
  source = "tfr://terraform-aws-modules/vpc/aws"
}
```

## 2. Initializing the Configuration

Run the following command to download and prepare the module in your working directory:

```bash theme={null}
terragrunt init
```

This initializes your Terragrunt configuration and fetches the specified module from the Terraform Registry.

## 3. Pinning a Module Version

To guarantee reproducible builds and avoid unintended upgrades, specify a version constraint:

```hcl theme={null}
terraform {
  source  = "tfr://terraform-aws-modules/vpc/aws"
  version = "~> 3.0"
}
```

Modules in the Registry follow semantic versioning. Locking to `~> 3.0` ensures you get all non-breaking updates in the 3.x series.

## 4. Updating to the Latest Matching Version

When you’re ready to pull in the newest matching release (within your version constraint), use:

```bash theme={null}
terragrunt get --update
```

This command refreshes your local copy of the module, incorporating any fixes or enhancements.

## 5. Security and Best Practices

<Callout icon="triangle-alert" color="#FF6B6B">
  Always verify the module’s publisher and review its source code before applying in production. Prefer modules marked as **Verified** or provided by official vendors to reduce risk.
</Callout>

* Review module inputs, outputs, and provisioners for security compliance.
* Check the [Terraform Registry](https://registry.terraform.io) page for the module’s documentation and changelog.
* Use version pinning to control when features and fixes are introduced.

## Links and References

* [Terraform Registry](https://registry.terraform.io)
* [Terragrunt Documentation](https://terragrunt.gruntwork.io/)
* [Terraform Modules Best Practices](https://www.terraform.io/docs/language/modules/develop/index.html)

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