> ## 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 a Git Repository
> Learn to reference Terraform modules in a private Git repository and manage authentication securely for reproducible Terraform runs.
In this guide, you’ll learn how to reference Terraform modules hosted in a private Git repository (GitHub, GitLab, Bitbucket, etc.) and manage authentication securely. By the end, you’ll be able to pin module versions for reproducible Terraform runs.
## Prerequisites
* A Terraform module stored in a private Git repository
* Credentials configured in your local environment (HTTPS token or SSH key)
* Terraform CLI installed on your workstation
## Authentication Methods
Choose one of the following authentication options to securely fetch private modules:
| Method | Description | Setup Commands |
| ----------------------------- | -------------------------------------------- | ------------------------------------------------------------------------------------------------------------ |
| HTTPS + Personal Access Token | Use a PAT stored in an environment variable. | `bash
export GIT_TOKEN="your_token_here"
`
Configure `~/.netrc` or a Git credential helper. |
| SSH Keys | Authenticate via your SSH keypair. | `bash
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_rsa
`
Add your public key to your Git provider. |
Avoid hard-coding tokens or keys in your `.tf` files. Instead, use environment variables, `~/.netrc`, or a Git credential helper.
## Referencing a Module in Terraform
Insert one of the following snippets into your `main.tf`. Replace ``, ``, and `modules/my_module` with your repository and path.
### HTTPS Example
```hcl theme={null}
module "my_module" {
source = "git::https://:${var.GIT_TOKEN}@github.com//.git//modules/my_module?ref=v1.0.0"
# Module inputs
example_var = "foo"
}
```
### SSH Example
```hcl theme={null}
module "my_module" {
source = "git::ssh://git@github.com//.git//modules/my_module?ref=v1.0.0"
# Module inputs
example_var = "foo"
}
```
* The double slash (`//modules/my_module`) specifies the subdirectory within the repository.
* The `?ref=v1.0.0` suffix pins the module to a tag, branch, or commit.
Embedding credentials in URLs can expose sensitive data if your configuration is shared. Use variables and environment-based authentication whenever possible.
## Initializing and Updating Modules
1. Initialize Terraform and download referenced modules:
```bash theme={null}
terraform init
```
2. After updating the remote module, refresh your local cache:
```bash theme={null}
terraform get -update
```
3. Review and apply your changes:
```bash theme={null}
terraform apply
```
## Best Practices
* Always pin module sources with `?ref=` to ensure reproducibility.
* Store API tokens and SSH keys outside of version control.
* Test module updates in a non-production workspace before rolling out.
## Links and References
* [Terraform Modules Documentation](https://www.terraform.io/docs/language/modules/index.html)
* [GitHub Personal Access Tokens](https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/creating-a-personal-access-token)
* [SSH Key Setup](https://docs.github.com/en/authentication/connecting-to-github-with-ssh)
* [Terraform CLI Commands](https://www.terraform.io/docs/cli/index.html)