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

Applying the VirtualBox builder

VirtualBox might not be considered a production hypervisor, but it is actually very helpful when learning Packer on your own. VirtualBox works on most common operating systems and gives you the option to connect and troubleshoot a VM during an image build. Note that the builders that support VirtualBox offer a headless option, meaning you will not launch VMs in a GUI during a build. This is handy if you are working remotely via SSH or using automation.

A caveat to the VirtualBox builder is lack of access to TTY from your Packer session. This means the machine’s text output won’t directly show up in Packer output. Provisioners executing over SSH have the handy ssh_pty option, which allows you to capture SSH output. For the rest, you should probably use headless = "false", which is the default and lets you view the VM in VirtualBox. Later, we will cover other builders such as QEMU, which can actually output all of a VM’...