Packer Image Builder

Packer is an open-source tool for creating identical machine images for multiple platforms from a single source configuration created by Mitchell Hashimoto in 2013, developed by HashiCorp, providing automated image building for Amazon EC2, Google Cloud, Azure, VMware, VirtualBox, Docker, QEMU, and other platforms, with features including provisioning through shell scripts, Ansible, Chef, Puppet, and custom provisioners, post-processing for image manipulation, variable templating, parallel builds across multiple platforms, and integration with CI pipelines, designed to enable immutable infrastructure by baking application code and configuration into versioned images, adopted by companies including HashiCorp, Disney, Target, and Cisco for their image management workflows. The configuration uses HashiCorp Configuration Language or JSON for defining builders, provisioners, and post-processors, with builders specifying the target platform and image parameters including instance type, source image, disk size, and network configuration, while provisioners execute scripts and configuration management tools inside the building instance to install software, configure services, and prepare the image, and post-processors manipulate the output including compressing, checksumming, and pushing to image registries. The parallel building feature enables building images for multiple platforms simultaneously, with each builder running as a separate goroutine, reducing total build time for multi-platform images, while the variable system enables parameterized builds with variables sourced from environment variables, variable files, and command-line flags. The template validation through the validate command. The manifest output for tracking built images. The integration with Vagrant. The Docker import and push. The cloud-init integration. Designed by Mitchell Hashimoto. Designed for DevOps teams.