terraform/website/source/docs/modules/sources.html.markdown

layout	page_title	sidebar_current	description
docs	Module Sources	docs-modules-sources	Explains the use of the source parameter, which tells Terraform where modules can be found.

Module Sources

As documented in the Usage section, the only required parameter when using a module is source. The source parameter tells Terraform where the module can be found and what constraints to put on the module. Constraints can include a specific version or Git branch.

Terraform manages modules for you: it downloads them, organizes them on disk, checks for updates, etc. Terraform uses this source parameter to determine where it should retrieve and update modules from.

Terraform supports the following sources:

• Local file paths

• GitHub

• BitBucket

• Generic Git, Mercurial repositories

• HTTP URLs

• S3 buckets

Each is documented further below.

Local File Paths

The easiest source is the local file path. For maximum portability, this should be a relative file path into a subdirectory. This allows you to organize your Terraform configuration into modules within one repository, for example:

module "consul" {
  source = "./consul"
}

Updates for file paths are automatic: when "downloading" the module using the get command, Terraform will create a symbolic link to the original directory. Therefore, any changes are automatically available.

GitHub

Terraform will automatically recognize GitHub URLs and turn them into a link to the specific Git repository. The syntax is simple:

module "consul" {
  source = "github.com/hashicorp/example"
}

Subdirectories within the repository can also be referenced:

module "consul" {
  source = "github.com/hashicorp/example//subdir"
}

These will fetch the modules using HTTPS. If you want to use SSH instead:

module "consul" {
  source = "git@github.com:hashicorp/example.git//subdir"
}

Note: The double-slash, //, is important. It is what tells Terraform that that is the separator for a subdirectory, and not part of the repository itself.

GitHub source URLs require that Git is installed on your system and that you have access to the repository.

You can use the same parameters to GitHub repositories as you can generic Git repositories (such as tags or branches). See the documentation for generic Git repositories for more information.

Private GitHub Repos

If you need Terraform to be able to fetch modules from private GitHub repos on a remote machine (like Atlas or a CI server), you'll need to provide Terraform with credentials that can be used to authenticate as a user with read access to the private repo.

First, create a machine user on GitHub with read access to the private repo in question, then embed this user's credentials into the source parameter:

module "private-infra" {
  source = "git::https://MACHINE-USER:MACHINE-PASS@github.com/org/privatemodules//modules/foo"
}

Note: Terraform does not yet support interpolations in the source field, so the machine username and password will have to be embedded directly into the source string. You can track GH-1439 to learn when this limitation is addressed.

BitBucket

Terraform will automatically recognize BitBucket URLs and turn them into a link to the specific Git or Mercurial repository, for example:

module "consul" {
  source = "bitbucket.org/hashicorp/consul"
}

Subdirectories within the repository can also be referenced:

module "consul" {
  source = "bitbucket.org/hashicorp/consul//subdir"
}

Note: The double-slash, //, is important. It is what tells Terraform that this is the separator for a subdirectory, and not part of the repository itself.

BitBucket URLs will require that Git or Mercurial is installed on your system, depending on the type of repository.

Generic Git Repository

Generic Git repositories are also supported. The value of source in this case should be a complete Git-compatible URL. Using generic Git repositories requires that Git is installed on your system.

module "consul" {
  source = "git://hashicorp.com/consul.git"
}

You can also use protocols such as HTTP or SSH to reference a module, but you'll have specify to Terraform that it is a Git module, by prefixing the URL with git:: like so:

module "consul" {
  source = "git::https://hashicorp.com/consul.git"
}

module "ami" {
  source = "git::ssh://git@github.com/owner/repo.git"
}

If you do not specify the type of source then Terraform will attempt to use the closest match, for example assuming https://hashicorp.com/consul.git is a HTTP URL.

The URLs for Git repositories support the following query parameters:

• ref - The ref to checkout. This can be a branch, tag, commit, etc.

module "consul" {
  source = "git::https://hashicorp.com/consul.git?ref=master"
}

Generic Mercurial Repository

Generic Mercurial repositories are supported. The value of source in this case should be a complete Mercurial-compatible URL. Using generic Mercurial repositories requires that Mercurial is installed on your system. You must tell Terraform that your source is a Mercurial repository by prefixing it with hg::.

module "consul" {
  source = "hg::http://hashicorp.com/consul.hg"
}

URLs for Mercurial repositories support the following query parameters:

• rev - The rev to checkout. This can be a branch, tag, commit, etc.

module "consul" {
  source = "hg::http://hashicorp.com/consul.hg?rev=default"
}

HTTP URLs

An HTTP or HTTPS URL can be used to redirect Terraform to get the module source from one of the other sources. For HTTP URLs, Terraform will make a GET request to the given URL. An additional GET parameter, terraform-get=1, will be appended, allowing you to optionally render the page differently when Terraform is requesting it.

Terraform then looks for the resulting module URL in the following order:

1. Terraform will look to see if the header X-Terraform-Get is present. The header should contain the source URL of the actual module.

2. Terraform will look for a <meta> tag with the name of terraform-get, for example:

<meta name=“terraform-get” content="github.com/hashicorp/example" />

S3 Bucket

Terraform can also store modules in an S3 bucket. To access the bucket you must have appropriate AWS credentials in your configuration or available via shared credentials or environment variables.

There are a variety of S3 bucket addressing schemes, most are documented in the S3 configuration. Here are a couple of examples.

Using the s3 protocol.

module "consul" {
  source = "s3::https://s3-eu-west-1.amazonaws.com/consulbucket/consul.zip"
}

Or directly using the bucket's URL.

module "consul" {
  source = "consulbucket.s3-eu-west-1.amazonaws.com/consul.zip"
}

Unarchiving

Terraform will automatically unarchive files based on the extension of the file being requested (over any protocol). It supports the following archive formats:

• tar.gz and tgz
• tar.bz2 and tbz2
• zip
• gz
• bz2