Why use Packer

This topic describes why you should use Packer to automate the creation of machine images over traditional pre-baked images, which are pre-configured digital images that include the necessary software, settings, and data.

Pre-baked images

Pre-baked machine images have a lot of advantages, but most people have been unable to benefit from them because images have been too tedious to create and manage. There are either no existing tools to automate the creation of machine images or they had too high of a learning curve. The result is that, prior to Packer, creating machine images threatened the agility of operations teams, and therefore aren't used, despite the massive benefits.

Packer changes all of this. Packer automates the creation of any type of machine image. It embraces modern configuration management by encouraging you to use a framework such as Chef or Puppet to install and configure the software within your Packer-made images.

Advantages of using Packer

Super fast infrastructure deployment. Packer images allow you to launch completely provisioned and configured machines in seconds, rather than several minutes or hours. This benefits not only production, but development as well, since development virtual machines can also be launched in seconds, without waiting for a typically much longer provisioning time.

Multi-provider portability. Because Packer creates identical images for multiple platforms, you can run production in AWS, staging/QA in a private cloud like OpenStack, and development in desktop virtualization solutions such as VMware or VirtualBox. Each environment is running an identical machine image, giving ultimate portability.

Improved stability. Packer installs and configures all the software for a machine at the time the image is built. If there are bugs in these scripts, they'll be caught early, rather than several minutes after a machine is launched.

Greater testability. After a machine image is built, that machine image can be quickly launched and smoke tested to verify that things appear to be working. If they are, you can be confident that any other machines launched from that image will function properly.