# Packer

> Packer is a HashiCorp tool that builds identical machine images, such as AWS AMIs and Docker images, from a single configuration file.

- Source: https://www.itwonderlab.com/packer/
- Published: 2026-10-03
- Updated: 2026-10-03
- Author: Javier Ruiz Jiménez (https://www.javierruizjimenez.com/)
- Site: IT Wonder Lab (https://www.itwonderlab.com/)

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**Packer** starts a temporary machine, runs your provisioners ([Ansible](https://www.itwonderlab.com/ansible/) or shell scripts), and saves the result as an image. The image is then used by [Terraform](https://www.itwonderlab.com/terraform/) to create servers that boot already configured, an approach called immutable infrastructure.

### Key concepts

- **Source**: the platform and base image, for example `amazon-ebs`.
- **Provisioner**: how the image is configured.
- **Plugin**: adds a platform, installed with `packer init`.
- Output for an [AMI](https://www.itwonderlab.com/aws-ami/) is a new image id.

### Learn it

Follow [Build an AWS AMI with Packer](https://www.itwonderlab.com/packer-build-aws-ami/).