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

Building and testing your plugin

The GNUMakefile scaffolding also includes simple test support. It would be wise to modify any test Packer templates to demonstrate every feature of your plugin fully. There is a helpful test target to put the test templates and mock data through your plugin. When ready, you can simply run make test and you will get an informative report of failures or issues:

$ make test
?       packer-plugin-nspawn    [no test files]
ok      packer-plugin-nspawn/builder/nspawn     0.047s
ok      packer-plugin-nspawn/datasource/nspawn  0.036s
?       packer-plugin-nspawn/version    [no test files]

Having this added to automation would also be a very wise move. A pre-commit hook can prevent broken code from being committed and also log one of these tests for compliance...