» Packer Build Environment

This page outlines the environment that Packer runs in within Terraform Enterprise.

» Supported Builders

Terraform Enterprise currently supports running the following Packer builders:

  • amazon-chroot
  • amazon-ebs
  • amazon-instance
  • digitalocean
  • docker
  • googlecompute
  • null
  • openstack
  • qemu
  • virtualbox-iso
  • vmware-iso

» Files

All files in the uploading package (via Packer push or GitHub), and the application from the build pipeline are available on the filesystem of the build environment.

You can use the file icon on the running build to show a list of available files.

Files can be copied to the destination image Packer is provisioning with Packer Provisioners.

An example of this with the Shell provisioner is below.

  "provisioners": [
      "type": "shell",
      "scripts": [

We encourage use of relative paths over absolute paths to maintain portability between Terraform Enterprise and local builds.

The total size of all files in the package being uploaded via Packer push or GitHub must be 5 GB or less.

If you need to upload objects that are larger, such as dmgs, see the packer push "Limits" documentation for ways around this limitation.

» Hardware Limitations

Currently, each builder defined in the Packer template receives the following hardware resources. This is subject to change.

  • 1 CPU core
  • 2 GB of memory
  • 20 GBs of disk space

» Environment Variables

You can set any number of environment variables that will be injected into your build environment at runtime. These variables can be used to configure your build with secrets or other key value configuration.

Variables are encrypted and stored securely.

Additionally, the following environment variables are automatically injected. All injected environment variables will be prefixed with ATLAS_

If the build was triggered by a new application version, the following environment variables are also available:

For any of the GITHUB_ attributes, the value of the environment variable will be the empty string ("") if the resource is not connected to GitHub or if the resource was created outside of GitHub (like using packer push or vagrant push).

» Base Artifact Variable Injection

A base artifact can be selected on the "Settings" page for a build configuration. During each build, the latest artifact version will have it's external ID (such as an AMI for AWS) injected as an environment variable for the environment.

The keys for the following artifact types will be injected:

You can then reference this artifact in your Packer template, like this AWS example:

  "variables": {
      "base_ami": "{{env `ATLAS_BASE_ARTIFACT_AWS_AMI_ID`}}"
  "builders": [
      "type": "amazon-ebs",
      "access_key": "",
      "secret_key": "",
      "region": "us-east-1",
      "source_ami": "{{user `base_ami`}}"

» Notes on Security

Packer environment variables in Terraform Enterprise are encrypted using Vault and closely guarded and audited. If you have questions or concerns about the safety of your configuration, please contact our security team at security@hashicorp.com.