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)
1
Part 1: Packer’s Beginnings
7
Part 2: Managing Large Environments
11
Part 3: Advanced Customized Packer

Parallel builds

Remember that builds happen in parallel by default. This is more apparent now as we add multiple sources to our build. Packer’s strength becomes more apparent in a multi-cloud deployment. Remember that Packer is a tool, not a platform or a service. Packer can be run whenever or however you want it to, but it must also be used responsibly. If you accidentally kick off 50 builds in parallel, they will all be started simultaneously. There is also no locking or state file, as with Terraform, so you may accidentally run the same build multiple times simultaneously, which will probably not be what you intended. If you use unique identifiers for each build instance, they will all build simultaneously. If you use fixed naming, then likely Packer’s builders will error, saying that certain resources it needs to create already exist and can’t be replaced.

In the early days of Packer’s in 2017, HashiCorp built a managed platform called Atlas, which...