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This cheat sheet provides a quick reference for some common Packer commands and concepts. Packer is an open-source tool for automating the creation of machine images (e.g., Amazon Machine Images, VirtualBox images, Docker containers) for multiple platforms from a single configuration.


To use Packer, you need to install it on your system. Installation methods vary depending on your operating system. Refer to the official Packer documentation for installation instructions.

Packer Concepts


Builders are responsible for creating machine images. Packer supports a variety of builders for different platforms, including AWS, Azure, VirtualBox, and more.

  • Create a machine image with a builder:
    packer build template.json


Packer configuration files, called templates, define what builders to use and how to create machine images.

  • Create a basic Packer template:

    "builders": [
    "type": "builder_name",
    "...": "..."
  • Use variables and provisioners in templates for more advanced image creation.


Variables in Packer templates allow you to parameterize your configuration.

  • Declare and use variables in a template:

    "variables": {
    "variable_name": "default_value"
    "builders": [
    "type": "builder_name",
    "variable_name": "{{user `variable_name`}}"
  • Define variable values at runtime using -var command-line flags.


Provisioners in Packer templates enable you to install and configure software on the machine image.

  • Use built-in provisioners like Shell, Ansible, or Chef to customize the image.


Post-processors allow you to transform the created machine image after the build process.

  • Examples include compressing images, copying them to a different location, or pushing them to a cloud provider.

Packer Command-Line

  • Validate a Packer template:

    packer validate template.json
  • Build a machine image using a Packer template:

    packer build template.json
  • Inspect a machine image without building it:

    packer inspect template.json
  • Create a custom variable file and pass it during the build process:

    packer build -var-file=my-vars.json template.json


This cheat sheet covers some common Packer commands and concepts. Packer simplifies the process of creating machine images for different platforms; refer to the official Packer documentation for more in-depth information and advanced usage.