Book Image

HashiCorp Packer in Production

By : John Boero
Book Image

HashiCorp Packer in Production

By: John Boero

Overview of this book

Creating machine images can be time-consuming and error-prone when done manually. HashiCorp Packer enables you to automate this process by defining the configuration in a simple, declarative syntax. This configuration is then used to create machine images for multiple environments and cloud providers. The book begins by showing you how to create your first manifest while helping you understand the available components. You’ll then configure the most common built-in builder options for Packer and use runtime provisioners to reconfigure a source image for desired tasks. You’ll also learn how to control logging for troubleshooting errors in complex builds and explore monitoring options for multiple logs at once. As you advance, you’ll build on your initial manifest for a local application that’ll easily migrate to another builder or cloud. The chapters also help you get to grips with basic container image options in different formats while scaling large builds in production. Finally, you’ll develop a life cycle and retention policy for images, automate packer builds, and protect your production environment from nefarious plugins. By the end of this book, you’ll be equipped to smoothen collaboration and reduce the risk of errors by creating machine images consistently and automatically based on your defined configuration.
Table of Contents (18 chapters)
Part 1: Packer’s Beginnings
Part 2: Managing Large Environments
Part 3: Advanced Customized Packer

Selecting a compression algorithm for Packer images

Compression is not a simple yes or no option. There are several ways to compress an image based on the type of image and how it’s formatted. Some image types support native compression and some also support encryption. The order in which encryption and compression are performed on images is important. Compression takes patterns and simplifies repetition to save space. Encryption randomizes data and makes it hard to read. If you encrypt a disk during the build and then attempt to compress it, compression will not be able to reduce the image size because the data is scrambled by encryption. Also, if your OS provides its own disk compression, then recompressing will not save any size but will take much more time to decompress before usage. Various image formats have their own standards for encryption and compression:

  • AMI: Optionally compressed and encrypted
  • QCOW2: Optionally compressed
  • VMDK: Optionally compressed...